Screening Libraries of Semifluorinated Arylene Bisimides to Discover and Predict Thermodynamically Controlled Helical Crystallization

Article abstract of DOI:10.1021/acscombsci.6b00143

Synthesis, structural, and retrostructural analysis of a library containing 16 self-assembling perylene (PBI), 1,6,7,12-tetrachloroperylene (Cl₄PBI), naphthalene (NBI), and pyromellitic (PMBI) bisimides functionalized with environmentally friendly AB₃ chiral racemic semifluorinated minidendrons at their imide groups via m = 0, 1, 2, and 3 methylene units is reported. These semifluorinated compounds melt at lower temperatures than homologous hydrogenated compounds, permitting screening of all their thermotropic phases via structural analysis to discover thermodynamically controlled helical crystallization from propeller-like, cogwheel, and tilted molecules as well as lamellar-like structures. Thermodynamically controlled helical crystallization was discovered for propeller-like PBI, Cl₄PBI and NBI with m = 0. Unexpectedly, assemblies of twisted Cl₄PBIs exhibit higher order than those of planar PBIs. PBI with m = 1, 2, and 3 form a thermodynamically controlled columnar hexagonal 2D lattice of tilted helical columns with intracolumnar order. PBI and Cl₄PBI with m = 1 crystallize via a recently discovered helical cogwheel mechanism, while NBI and PMBI with m = 1 form tilted helical columns. PBI, NBI and PMBI with m = 2 generate lamellar-like structures. 3D and 2D assemblies of PBI with m = 1, 2, and 3, NBI with m = 1 and PMBI with m = 2 exhibit 3.4 ? π-π stacking. The library approach applied here and in previous work enabled the discovery of six assemblies which self-organize via thermodynamic control into 3D and 2D periodic arrays, and provides molecular principles to predict the supramolecular structure of electronically active components.

Full text of DOI:10.1021/acscombsci.6b00143

Subscriber access provided by The Bodleian Libraries of The University of Oxford
Article
Screening Libraries of Semifluorinated Arylene Bisimides to Discover
and Predict Thermodynamically Controlled Helical Crystallization
Ming-Shou Ho, Benjamin E. Partridge, Hao-Jan Sun, Dipankar Sahoo,
Pawaret Leowanawat, Mihai Peterca, Robert Graf, Hans W. Spiess, Xiangbing
Zeng, Goran Ungar, Paul A. Heiney, Chain-Shu Hsu, and Virgil Percec
ACS Comb. Sci., Just Accepted Manuscript • DOI: 10.1021/acscombsci.6b00143 • Publication Date (Web): 31 Oct 2016
Downloaded from http://pubs.acs.org on November 5, 2016
Just Accepted
“Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted
online prior to technical editing, formatting for publication and author proofing. The American Chemical
Society provides “Just Accepted” as a free service to the research community to expedite the
dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts
appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been
fully peer reviewed, but should not be considered the official version of record. They are accessible to all
readers and citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered
to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published
in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just
Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor
changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers
and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors
or consequences arising from the use of information contained in these “Just Accepted” manuscripts.
ACS Combinatorial Science is published by the American Chemical Society. 1155
Sixteenth Street N.W., Washington, DC 20036
Published by American Chemical Society. Copyright © American Chemical Society.
However, no copyright claim is made to original U.S. Government works, or works
produced by employees of any Commonwealth realm Crown government in the course
of their duties.

Page 1 of 21
ACS Combinatorial Science
1
2
3
4
5
6
7
8
9
Screening Libraries of Semifluorinated Arylene Bisimides to
Discover and Predict Thermodynamically Controlled Helical
Crystallization
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
Ming-Shou Ho,a Benjamin E. Partridge,a Hao-Jan Sun,a,b Dipankar Sahoo,a,b Pawaret
Leowanawat,a Mihai Peterca,a,b Robert Graf,c Hans W. Spiess,c Xiangbing Zeng,d Goran Ungar,d,e
Paul A. Heiney,b Chain-Shu Hsu,f and Virgil Percec*,a
a Roy & Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania
19104-6323, United States
b Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6396, United
States
c Max-Planck Institute for Polymer Research, 55128 Mainz, Germany
d Department of Materials Science and Engineering, University of Sheffield, Sheffield S1 3JD, United Kingdom
e Department of Physics, Zhejiang Sci-Tech University, Hangzhou 3110018, China
f Department of Applied Chemistry, National Chiao Tung University, 1001 Ta Hsueh Road, Hsin-Chu 30049, Taiwan
ABSTRACT: Synthesis, structural and retrostructural analysis of a library containing sixteen self-assembling perylene (PBI),
1,6,7,12-tetrachloroperylene (Cl4PBI), naphthalene (NBI), and pyromellitic (PMBI) bisimides functionalized with environ-
mentally friendly AB3 chiral racemic semifluorinated minidendrons at their imide groups via m = 0, 1, 2, and 3 methylene
units is reported. These semifluorinated compounds melt at lower temperatures than homologous hydrogenated compounds,
permitting screening of all their thermotropic phases via structural analysis to discover thermodynamically controlled helical
crystallization from propeller-like, cogwheel, and tilted molecules as well as lamellar-like structures. Thermodynamically
controlled helical crystallization was discovered for propeller-like PBI, Cl4PBI and NBI with m = 0. Unexpectedly, assemblies
of twisted Cl4PBIs exhibit higher order than those of planar PBIs. PBI with m = 1, 2, and 3 form a thermodynamically controlled
columnar hexagonal 2D lattice of tilted helical columns with intracolumnar order. PBI and Cl4PBI with m = 1 crystallize via a
recently discovered helical cogwheel mechanism, while NBI and PMBI with m = 1 form tilted helical columns. PBI, NBI and
PMBI with m = 2 generate lamellar-like structures. 3D and 2D assemblies of PBI with m = 1, 2, and 3, NBI with m = 1 and PMBI
with m = 2 exhibit 3.4 Å π–π stacking. The library approach applied here and in previous work enabled the discovery of six
assemblies which self-organize via thermodynamic control into 3D and 2D periodic arrays, and provides molecular principles
to predict the supramolecular structure of electronically active components.
Introduction
their decomposition temperatures.31,32 By definition, 3D
crystals and 2D liquid crystals with a high degree of order
self-organize via kinetically controlled processes while low
order 1D and 2D mostly by thermodynamically controlled
mechanisms. Kinetically controlled crystallization is deter-
mined by heating and cooling rates and by the thermal his-
tory of the sample, and hence reproducible formation of a
crystalline array is tedious. In contrast, crystalline phases
assembled via a thermodynamically controlled process are
generated predictably and reproducibly without depend-
ence on the thermal history of the sample.31,32
Planar self-assembling electron-accepting arylene bisi-
mides, such as unsubstituted and substituted perylene bisi-
mides (PBI),1–8 naphthalene bisimides (NBI),9 and pyro-
mellitic bisimides (PMBI),10–12 and their supramolecular as-
semblies, have been investigated for a variety of applica-
tions, including industrial pigments,1 models for biological
systems,13–18 and n-type semiconductors for photovoltaic
and organic electronics.3,19–21 Since the publication of com-
prehensive reviews in 2016,5–8 this area continues to de-
velop apace.22–30 Key to successful application of planar ar-
omatic bisimides is the generation of highly ordered and
suitably organized crystalline arrays that form preferen-
tially via a thermodynamically controlled process below
ACS Paragon Plus Environment

ACS Combinatorial Science
Scheme 1. Synthesis of Semifluorinated Amine Dendron 5aa
Page 2 of 21
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
aReagents and conditions: (i) Conc. HNO3, MeCN, cat. AIBN, o/n (50 °C); (ii) pyridine hydrochloride, 40 min (200 °C); (iii) tBuOK,
CF2=CFOC3F7, DMF, 2 h (0 °C) then o/n (RT); (iv) NH2NH2·H2O, graphite, EtOH/THF (2:1), 19 h (reflux).
The structural and retrostructural analysis2,33–35 of com-
plex functional systems2,36 through generational,37–40 com-
bined generational41 and deconstructive42 library ap-
proaches has been employed for the discovery and, after
elucidation of the self-organization mechanism, prediction
of programmed primary and secondary structures that self-
organize into tertiary structures. These first principles have
been employed in the design of systems with complex func-
tions,2,36 such as transmembrane water channels,43 altering
the chemoselectivity of organic reactions to discover a he-
lix-helix transition and generate molecular machines,44,45
enhancement of charge carrier mobility,46 mimics of com-
plex biological membranes47,48 and their programmed gly-
cans,49–51 homochiral self-sorting in the crystal state,52 and
programmed polymer backbone conformation,53 via first
principles also known as materials genome. Recently Pm3¯ n
supramolecular assemblies pioneered with self-assembling
dendrons were also discovered in block copolymers,54,55
other molecular building blocks56,57 and in surfactants.58
compared to perhydrogenated alkanes.75 However, these
linear perfluorinated segments degrade to form perfluo-
rooctanoic acid, which is toxic and biopersistent.75–79 In con-
trast, semifluorinated dendrons derived from perfluoropro-
pyl vinyl ether (PPVE)73 degrade into environmentally tol-
erable perfluoropropyl chains.80,81 These semifluorinated
chains are of a length that, in comparison with previous
studies on hydrogenated components,82–84 would be antici-
pated to promote thermodynamically controlled crystalli-
zation of supramolecular PBI assemblies. Indeed, electron-
accepting NBI derivatives with the same semifluorinated
dendrons with m = 3 exhibited two thermodynamically con-
trolled columnar hexagonal phases.66 However, no system-
atic library of semifluorinated aromatic bisimides has been
screened to elaborate the effect of molecular changes in the
primary structure on their ability to generate desirable
thermodynamically controlled crystalline phases has been
reported to date.
Here we report the synthesis, structural and retrostruc-
tural analysis of a library of arylene bisimides based on PBI,
tetrachlorinated PBI (Cl4PBI), NBI, and PMBI, dendronized
with environmentally acceptable chiral racemic semifluori-
nated dendrons. The melting temperature of these com-
pounds allowed access to the entire range of their self-orga-
nized assemblies for structural and retrostructural analysis.
Appropriate choice of molecular parameters permits access
to various desirable supramolecular assemblies and func-
tions, including thermodynamically controlled crystalliza-
tion,31,67 close contact aromatic stacking,85,86 and cogwheel-
type self-organization.32
Models for their self-assembly have also been elaborated.59–
63
Among previous work on libraries of arylene bisi-
mides,31,32,64–67 a combined generational approach was ap-
plied to a series of PBI derivatives with two identical self-
assembling hydrogenated minidendrons, (3,4,5)nG1-m-PBI,
where n is the number of carbons in the aliphatic chain and
m is the number of methylenic units in the linker between
the dendron and the imide group of the PBI core. The appro-
priate selection of n and m transforms crystallization of
their supramolecular assemblies from a kinetically con-
trolled process into a thermodynamically controlled
one.31,64,65
Results and Discussion
Synthesis of Semifluorinated PBI, Cl4PBI, NBI, and
PMBI. The semifluorinated dendronized arylene bisimides
reported here are denoted Ar(m), where Ar is the name of
the bisimide core (P – perylene (PBI); PCl – tetrachlorinated
perylene (Cl4PBI); N – naphthalene (NBI); B – benzene
(PMBI)), and m denotes the number of methylene units be-
tween the core imide and the phenyl ring of the dendron.
Combining each of the four aromatic bisimides with each of
four semifluorinated dendrons (with m = 0, 1, 2, and 3) fur-
nishes a library of sixteen compounds. The synthesis of first
generation semifluorinated amine dendron with m = 0 (5a)
is outlined in Scheme 1.
However, the use of hydrogenated dendronized aromatic
bisimides in organic electronics is hampered by various fac-
tors, including high melting temperature sometimes ex-
ceeding their decomposition temperature, and sensitivity to
air and moisture.68,69 In contrast, fluorinated dendrons con-
fer resistance to moisture and alter the thermal and ther-
modynamic stability of assemblies of self-organizing build-
ing blocks.66,70–74 Previous studies of self-assembling den-
drons with n-dodecyl substituents had shown that substitu-
tion of 8 out of 12 methylenic units with linear CF2 segments
provides an optimum enhancement of thermal stability,70
arising from the higher rigidity of linear perfluoroalkanes
ACS Paragon Plus Environment

Page 3 of 21
ACS Combinatorial Science
Scheme 2. Synthesis of Semifluorinated PBIs (P(m)), Cl4PBIs (PCl(m)), NBIs (N(m)), and PMBIs (B(m)) with m = 0, 1,
2, and 3a
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
aReagents and conditions: (i) Zn(OAc)2·H2O, quinoline, 4 h (180 °C); (ii) cat. DMAP, DMF, o/n (130 °C).
Semifluorinated aromatic bisimides with m = 0, 1, 2, and
3 based on PBI (the P series: P(0), P(1), P(2), and P(3)),
Cl4PBI (the PCl series: PCl(0), PCl(1), PCl(2), and PCl(3)),
NBI (the N series: N(0), N(1), N(2), and N(3)), and PMBI
(the B series: B(0), B(1), B(2), and B(3)) were synthesized
as outlined in Scheme 2.
with the amines 5a, 5b, 5c, and 5d via one of two methods.
Dianhydrides 6, 8, and 9 are commercially available. Tetra-
chlorinated perylene-3,4,9,10-tetracarboxylic dianhydride
7 was synthesized from 6 using a modified literature proce-
dure.67,88 Treatment of 6 with chlorosulfonic acid and a cat-
alytic amount of iodine at 65 °C for 20 h, followed by re-
moval of insoluble starting material by hot filtration, af-
forded 7 in 94% yield, as an orange solid used without pu-
rification.
3,4,5-Trimethoxybenzoic acid (1) underwent AIBN-
mediated nitration in acetonitrile to give 3,4,5-trimethox-
ynitrobenzene (2) in 69% yield after purification by flash
column chromatography (FCC) on silica gel eluted with
EtOAc/hexanes (1:5).72 Demethylation of nitroarene 2 with
pyridine hydrochloride at 200 °C in bulk provided 3,4,5-tri-
hydroxynitrobenzene (3) in 78% yield after FCC on silica gel
(eluted with EtOAc/hexanes, 1:3).72 Nucleophilic addition of
3 to perfluoropropyl vinyl ether (PPVE) was achieved in
48% yield with a catalytic amount of potassium tert-butox-
ide in dry DMF to give 4, which was purified by FCC on neu-
tral alumina, eluting with EtOAc/hexanes (1:20).73 Subse-
quent reduction of 4 with hydrazine hydrate and graphite
in a refluxing mixture of ethanol and THF (2:1) afforded
semifluorinated amine dendron 5a, with m = 0, in 58% yield
after purification by FCC on neutral alumina, eluting with
EtOAc/hexanes (1:4).82,87 Semifluorinated dendronized
amines with m = 1, 2 and 3 (5b, 5c, and 5d, respectively)
were synthesized as reported.66
Treatment of 6 or 7 with 5a, 5b, 5c, or 5d and
Zn(OAc)2·H2O in quinoline for 4 h at 180 °C to afford P(m)
and PCl(m), respectively, with m = 0, 1, 2, or 3, in 20–58%
yield after purification by FCC on silica gel with chloroform
as eluent and precipitation into MeOH to remove traces of
ionic impurities.82 Heating 8 or 9 with 5a, 5b, 5c, or 5d and
a catalytic amount of DMAP in DMF at 130 °C for 16 h gave
N(m) and B(m), with m = 0, 1, 2, or 3 in 20–58% yield after
FCC (silica gel, EtOAc/hexanes, 1:3).89 P(m), PCl(m), N(m),
and B(m) exhibit good solubility in THF and moderate sol-
ubility in CHCl3.
Thermal, Structural and Retrostructural Analysis of
the Assemblies of Semifluorinated PBI, Cl4PBI, NBI, and
PMBI Derivatives by DSC and XRD. Differential scanning
calorimetry (DSC) experiments were used to determine
transition temperatures and their corresponding enthalpy
changes. DSC experiments performed at different
The sixteen dendronized aromatic bisimides were syn-
thesized by condensation of the bisanhydrides 6, 7, 8, and 9
ACS Paragon Plus Environment

ACS Combinatorial Science
Page 4 of 21
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
Figure 1. DSC traces of (a) semifluorinated PBIs P(m) and (b) semifluorinated Cl4PBIs PCl(m) recorded with heating and cooling
rates of 2 °C/min. Phases determined by XRD, transition temperatures, and associated enthalpy changes (in parentheses in
kcal/mol) are indicated.
heating and cooling rates allow discrimination between
ordered periodic arrays assembled via a thermodynami-
cally or kinetically controlled process.82–84 Phase transitions
associated with thermodynamically controlled processes
are characterized by a lack of scan rate dependence of the
transition temperature and its associated enthalpy change
and little supercooling, whereas kinetically controlled
phase transitions show significant dependence on scan rate,
significant supercooling, and highly dissimilar enthalpy
changes in heating and cooling scans. DSC traces of the P,
PCl, N, and B series were measured at 10 °C/min (Support-
ing Figure SF1) and 2 °C/min (Figures 1 and 2). Phases de-
noted in Figures 1 and 2 were determined by X-ray diffrac-
tion (XRD) as discussed later. Note that all values of the iso-
tropization temperature (Ti) mentioned in the discussion
refer to Ti upon second heating at 10 °C/min, unless other-
wise stated.
Ti values than RH-PBIs with n = 12, but lower Ti values than
RH-PBIs with n = 6 (Supporting Table ST1).82 This difference
in Ti where n = 12 is largest for the m = 3 compound (91 °C),
and decreases with decreasing m (68 °C for m = 2) such that
there is almost no difference in Ti of semifluorinated P(0)
and P(1) and RH-PBIs (9 °C for both m = 0 and 1). The P se-
ries evidences a general correlation between decreasing
linker length, m, and increasing Ti. Decreasing m reduces the
flexibility of the imide-dendron linker (Scheme 2), limiting
the conformational freedom of the dendron and enhancing
the ability of the dendronized bisimides to pack into peri-
odic arrays. However, this trend is not perfect in the P se-
ries. Ti of P(3) is 14 °C higher than that of P(2), perhaps be-
cause the more flexible m = 3 compound can adopt a more
favorable supramolecular packing (see XRD discussion
later).
Semifluorinated dendrons in P(0) and P(1) transform
their self-organization from a kinetically controlled to a
thermodynamically controlled process and promotes for-
mation of 3D crystalline assemblies rather than 2D periodic
arrays. P(0) exhibits a single thermodynamically
The Ti values of P(1), P(2), and P(3) are comparable to
those of analogous hydrogenated PBIs (RH-PBIs),
(3,4,5)nG1-m-PBI with m = 1, 2, and 3 (Supporting Scheme
SS1).82–84 Semifluorinated P(1), P(2), and P(3) have higher
ACS Paragon Plus Environment

Page 5 of 21
ACS Combinatorial Science
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
Figure 2. DSC traces of (a) semifluorinated NBIs N(m) and (b) semifluorinated PMBIs B(m) recorded with heating and cooling
rates of 2 °C/min. Phases determined by XRD, transition temperatures, and associated enthalpy changes (in parentheses in
kcal/mol) are indicated.
controlled crystalline phase (a 3D body-centered ortho-
rhombic crystal, Φc-ok) below its Ti of 358 °C. This contrasts
with (3,4,5)12G1-0-PBI, which exhibits a mixture of kinet-
ically controlled 2D and 3D phases below 250 °C, and a 2D
columnar hexagonal array with short range intracolumnar
order (Φhio) between 250 °C and Ti (372 °C). Thermody-
namically controlled self-organization is also observed for
the high temperature 2D Φhio phase of P(m) with m = 1, 2,
and 3. Hence all four compounds in the P series self-organ-
ize into at least one 2D or 3D array via thermodynamic con-
trol.
were evidenced by XRD. P(3) also generates an undeter-
mined 3D crystalline phase of structure (Φx) via kinetic con-
trol. The readily observed crystalline phases in P(1), P(2),
and P(3) contrast the hydrogenated (3,4,5)12G1-m-PBI
with m = 1, 2, and 3 for which crystalline phases were ob-
served only with heating at a slow rate of 1 °C/min.
Tetrachlorination of the PBI core distorts its planarity
due to steric and electronic repulsion between adjacent
chlorine atoms.68,90–92 Single-crystal XRD studies demon-
strated that this distortion induces a twist in the PBI core of
35–37°, which shows little dependence on the identity of
the groups attached to the imide positions of the Cl4PBI
core.68,90–92 A previous study67 comparing the supramolecu-
lar assemblies of RH-PBI and hydrogenated Cl4PBI deriva-
tives (RH-Cl4PBI) showed that RH-Cl4PBIs exhibited lower
values of Ti than RH-PBIs, as expected from the twisting of
the aromatic core and the subsequent disruption to π–π
stacking between adjacent molecules. However, all phases
exhibited by RH-Cl4PBIs with m = 0, 1, and 2 were unexpect-
edly crystalline and of higher order than analogous RH-PBIs.
io
In addition to its thermodynamically controlled Φh
phase, P(1) exhibits two 3D columnar monoclinic crystal-
line phases formed via kinetic control: Φmk1, observed at 10
and 2 °C/min, and Φmk2, observed between 120 and 131 °C
only upon heating at 2 °C/min (Figure 1a). P(2) forms a 3D
k
crystalline Φs–o phase below 109 °C with slow heating (2
k
°C/min). The transition between the low temperature Φs–o
phase and high temperature Φhio phase is readily observed
by DSC upon first heating but is barely evident in subse-
quent cooling and heating due to a reduction in the enthalpy
of the phase transition between these phases. Both phases
k
Two of these crystalline phases (Φc–o and Φmk) were gen-
erated via thermodynamic control in the m = 0 RH-Cl4PBI.
ACS Paragon Plus Environment

ACS Combinatorial Science
Page 6 of 21
Solid state NMR experiments confirmed a more regular the as prepared sample, which is an oil at room tempera-
1
2
3
4
5
6
7
8
packing in RH-Cl4PBIs than in RH-PBIs.
ture. The formation of crystalline phases in N(1) and N(2)
and lack of crystalline phases in N(3) parallels the behavior
of (3,4,5)PPVEG1-m-S4NBI,66 for which crystalline phases
were observed only in the m = 1 and 2 derivatives.
Like P(0), semifluorinated PCl(0) exhibits only a single
k
3D crystalline Φc–o phase formed under thermodynamic
control (Figure 1b). The Ti of PCl(0) is 85 °C lower than that
of P(0), as expected from the disruption of planarity in the
PCl(0) core. The generation of a single crystalline phase in
PCl(0) is consistent with the exclusively crystalline phases
in RH-Cl4PBI and further evidences that the disordered
Cl4PBI core generates high degrees of order in its supramo-
lecular assemblies.67
The B series contains the smallest possible aromatic
core–a benzene ring–and therefore have the lowest ratio of
aromatic to semifluorinated regions reported here. DSC
traces for the B series are shown in Figure 2b. As for the P,
PCl, and N series, decreasing the size of the planar aromatic
region decreases Ti: Ti of B(0) (86 °C) is the lowest of all four
m = 0 compounds (Ti values of N(0), PCl(0) and P(0) are
176, 273 and 358 °C, respectively). B(0) generates a single
crystalline phase, as observed in P(0), PCl(0), and N(0).
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
As observed for the P series, increasing m results in a gen-
erally decreased Ti for the PCl series. PCl(1) has a Ti of 125
°C, below which PCl(1) generates a single crystalline 3D Φh
phase accessed via an exothermic crystallization upon heat-
ing from the as prepared sample (Figure 1b). PCl(2) gener-
ates an unidentified disordered periodic array (Ti = 53 °C)
whereas PCl(3) exhibits a 2D Φhio phase (Ti = 80 °C). After
heating to the isotropic state, neither phase is reformed in
PCl(2) or PCl(3) upon cooling, even at 2 °C/min (Figure
1b). In contrast, the hydrogenated counterpart to PCl(2)
k
k
However, this Φh phase in B(0) is generated via a kinet-
ically controlled process, rather than a thermodynamically
controlled process as observed for the other m = 0 com-
k
pounds. In the as prepared sample, B(1) exhibits a Φm
phase which could not be regenerated with subsequent
cooling and heating cycles, even at the slow rate of 2 °C/min
(Figure 2b). The correlation between increasing m and de-
creasing Ti seen in the P, PCl, and N series is observed too
for B(0), B(1), and B(3). However, B(2) provides a notable
exception to this trend. Indeed, its Ti of 96 °C is higher than
that of B(0) (86 °C). B(2) also disobeys the trend of decreas-
ing thermal stability with decreasing planar aromatic re-
gion; Ti of B(2) is higher than that of N(2) and PCl(2) (96 °C
vs 83 and 53 °C, respectively). B(2) forms a 3D Φs–ok phase
k
k
self-organizes into two crystalline phases (Φc–o and Φm
)
below its Ti of 108 °C. Substitution of semifluorinated for
hydrogenated dendrons decreases Ti of Cl4PBI compounds
with m = 1, 2, and 3 (Supporting Table ST1).
The N series also exhibits the trend of decreasing Ti with
increasing m (Figure 2a) seen for the PCl series and, to a
lesser extent, for the P series. The Ti of N(0) is 176 °C, sig-
nificantly lower than Ti of P(0) and PCl(0) (358 and 273
°C,), as expected from the lower degree of π–π stacking
available to molecules of N(0) due to their smaller aromatic
core. N(1) and N(2) have lower Ti values than N(0) (89 and
83 °C, respectively, vs 176 °C), and N(3) exhibits only an iso-
tropic phase.
k
in the as prepared sample, with a transition to a 3D Φc–o
phase at 80 or 77 °C upon first heating at 10 or 2 °C/min,
respectively. In subsequent cooling and heating cycles, only
the Φc–ok phase is observed. We propose that the unexpect-
edly high melting temperature of B(2) arises from reduced
steric interactions between neighboring molecules in the
helical supramolecular columns of B(2). B(3), like N(3), ex-
hibits no discernable periodic arrays and is an oil at room
temperature. The physical properties of electronic liquids
such as N(3) and B(3) may be of fundamental interest.
In contrast to the P series, the PCl series, and reported
semifluorinated
(3,4,5)PPVEG1-m-S4NBI
(Supporting
Scheme SS1),66,93 which all exhibited a mixture of 2D and 3D
phases, N(m) with m = 0, 1, and 2 exhibit only 3D crystalline
arrays after first heating. N(0) exhibits a single, thermody-
namically controlled crystalline columnar hexagonal phase
A summary of the thermal analysis of semifluorinated
PBI, Cl4PBI, NBI, and PMBI derivatives is presented in Sup-
porting Tables ST2 and ST3.
k
io
(Φh ) below Ti. N(1) exhibits a 2D Φh phase upon first
heating which is not reformed upon subsequent heating or
cooling and hence represents a nonequilibrium phase
formed during sample preparation. Instead, N(1) forms a
Structural and Retrostructural Analysis of the Assem-
blies of Semifluorinated PBI, Cl4PBI, NBI, and PMBI by
Oriented Fiber XRD and Simulation of XRD of their Su-
pramolecular Models. Phases were determined by analy-
sis of XRD patterns of oriented fibers (Figures 3 to 6), gen-
eration of supramolecular models (Figures 3 to 6) and com-
parison of experimental XRD data with XRD simulated from
those models (Supporting Figures SF3 to SF6).33,52,84
k
3D Φc–o phase, observed by DSC with slow heating and
cooling (2 °C/min) or upon quicker heating (10 °C/min) via
an exotherm at 46 °C. N(2) exhibits a kinetically controlled
3D crystalline Φs–ok phase which shows a large dependence
on heating and cooling rate. At 2 °C/min, the as prepared
sample exhibits the Φs–ok phase, which melts at 94 °C and is
reformed after a large degree of supercooling (48 °C) at 46
The presence of numerous sharp, well resolved diffrac-
tion peaks in the quadrants of the XRD patterns of P(0),
P(1), P(2), and P(3) (Figure 3) indicates high molecular or-
der indicative of crystalline supramolecular arrays. Fur-
thermore, the presence of off-meridional reflections
k
°C. At 10 °C/min, the Φs–o phase is not regenerated upon
cooling the isotropic melt to –50 °C. A second heating re-
forms the Φs–ok phase at 23 °C, as evidenced by an exother-
mic peak in DSC (Supporting Figure SF1c, right). N(3) ex-
hibits no discernable periodic arrays, even at 2 °C/min from
ACS Paragon Plus Environment

Page 7 of 21
ACS Combinatorial Science
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
Figure 3. XRD patterns collected from oriented fibers of the P series (a–d) and schematic illustrations of molecular models for the
P series (e–g). Temperature, phase, lattice parameters, layer lines and fiber axis are indicated, as appropriate. Phase notation: Φc–
k – columnar centered orthorhombic crystalline phase; Φs–ok – columnar simple orthorhombic crystalline phase; Φhio – 2D colum-
o
nar hexagonal phase with short range intracolumnar order. Color code: green – C, aromatic core; yellow – C, dendron phenyl ring;
grey – C, dendron linker; white – H; red – O; dark blue – N; light blue and orange – semifluorinated chains.
forming a cross-pattern indicate long-range helical order
that is correlated between columns, observed in P(1), N(0),
N(1), B(0), and B(1).2,33,34
along the column, with neighboring tetramers rotated by
90° with respect to each other to generate a helical column
with 8 molecules (4 column strata) in its unit cell. The inter-
dimer π–π stacking distance of 5.1 Å in P(0) is similar to
that of the Φhio phase of m = 0 RH-PBI (4.8 Å) due to the pro-
peller-like conformation of the m = 0 dendrons which limits
the stacking distance between molecules and prevents close
contact π–π stacking (3.3–3.8 Å).85,86
The P, PCl, N, and B series generate three classes of helical
structures: propeller-like, which refers to the propeller-
like molecular conformation of m = 0 molecules in which the
phenyl ring of the dendron is twisted out of the plane of the
aromatic core; cogwheel,32 which refers to a model recently
reported by our laboratory in which the semifluorinated
chains on the periphery of the dendron are aligned parallel
to the column axis; and tilted, in which the semifluorinated
chains are tilted with respect to the column axis.
P(1) forms two kinetically controlled crystalline mono-
clinic phases, Φmk1 (Figure 3b, f) and Φmk2, and a thermody-
io
namically controlled 2D columnar hexagonal array, Φh
k1
(Supporting Figure SF2b). In both Φm and Φmk2, single
molecules are stacked with a relative rotation of 36° be-
tween neighboring strata. As will be discussed later, molec-
ular modeling and reconstruction of the XRD pattern indi-
All three helical structures are observed in the P series.
Molecules in the helical columns of the Φc–o of P(0) adopt
k
a propeller-like conformation which avoids steric hin-
drance between the otherwise coplanar phenyl ring and bi-
simide (Figure 3a, e). Taking the volume of the unit cell of
P(0) from XRD-derived lattice parameters, together with its
experimental density (1.71 g/cm3), it was determined that
cate that Φmk2 of P(1) self-organizes via a cogwheel helical
k1
model.32 The difference between the structures of the Φm
,
Φmk2, and Φhio phases in P(1) lies in the supramolecular ar-
rangement of the helical columns. The kinetically controlled
Φmk2 phase involves a slight distortion of the columns from
a perfect hexagonal array, suggesting a deviation from a
perfectly symmetric column, along with an increase in the
average column diameter to 25.3 Å. In the thermodynami-
k
the supramolecular columns in the Φc–o phase of P(0) are
constructed with two molecules per column stratum of
thickness 5.1 Å. Simulations of XRD patterns were unable to
exactly reproduce the experimental pattern (Figure 3a).
The most consistent model (Figure 3e) suggests that the PBI
cores of the two molecules in each column stratum are co-
planar and arranged side-by-side within the stratum, form-
ing a planar dimer. Each dimer is rotated by 45° with re-
spect to its adjacent dimer. Together, this tetramer repeats
io
cally controlled high temperature Φh phase, observed
above 123 °C, these columns are arranged in a 2D hexagonal
array with column diameter 27.6 Å. This increase in column
diameter suggests a larger degree of disorder in the semi-
fluorinated region, as expected at
ACS Paragon Plus Environment

ACS Combinatorial Science
Page 8 of 21
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
Figure 4. XRD patterns collected from oriented fibers of the PCl series (a–d) and schematic illustrations of molecular models for
PCl(0) (e) and PCl(1) (f). Temperature, phase, lattice parameters, layer lines and fiber axis are indicated, as appropriate. Phase
notation: Φc–ok – columnar centered orthorhombic crystalline phase; Φhk – columnar hexagonal crystalline phase; Φx – unidenti-
fied disordered 2D columnar phase; Φhio – 2D columnar hexagonal phase with short range intracolumnar order. Color code: green
– C, aromatic core; yellow – C, dendron phenyl ring; grey – C, dendron linker; white – H; red – O; dark blue – N; light blue and or-
ange – semifluorinated chains.
higher temperature. In contrast, the lattice parameters of
the low temperature Φm phase indicate a substantial de-
from XRD (Figure 3c), almost identical to that in P(1). As for
P(1), the molecules of P(2) arrange into a 2D thermody-
namically controlled Φhio phase with short range inter- and
intra-columnar order at high temperature (Supporting Fig-
ure SF2c).
k1
viation from symmetric columns. So far the exact nature of
this distortion was not ascertained via molecular modeling
and XRD reconstruction studies. However, we can assume
that there must be significant disorder in the semifluori-
nated portions of the dendrons to adequately fill the unit
cell determined by XRD. In all three phases, each column
P(3) assembles into helical columns in which molecules
io
are separated by 3.4 Å, to give a 2D Φh phase with short
range helical order at elevated temperature (Figure 3d).
P(3) additionally forms an unidentified crystalline Φx phase
at low temperature (Supporting Figure SF2d), which has a
large unit cell and most likely represents a non-columnar
arrangement of molecules. This crystalline Φx phase has a
well-defined c parameter along the fiber axis (~55 Å) and a
characteristic distance of ~62 Å in the ab-plane. In sum-
mary, P(m) molecules with m = 0, 1, 2, and 3 self-assemble
to give 3D crystals at low temperature. The 3D crystal of
P(0) is formed via a thermodynamically controlled process.
P(0), P(1) and P(2) exhibit propeller-like helical, cogwheel
helical and lamellar-like structures, respectively. P(m) with
m = 1, 2, and 3 also generate thermodynamically controlled
2D columnar hexagonal Φhio phases with short π–π stacking
distances of 3.4 or 3.5 Å at higher temperature.
io
stratum of 3.4 Å contains only a single molecule. The Φh
phase is characterized by a lower degree of intra- and inter-
columnar correlations, with shorter range helical order, but
the average π–π distance between molecules is also 3.4 Å
(Supporting Figure SF2b), which represents close contact
between aromatic cores.85,86 The methylene linker in P(1)
permits tilting of the dendron with respect to the stratal
plane, reducing the unfavorable steric interactions between
propeller-like molecules of P(0) and permitting a closer in-
termolecular arrangement (3.4 Å in P(1) vs 5.1 Å in P(0)).
This closer arrangement is also supported by solid state
NMR to be discussed later. The 3.4 Å π–π distance of the
three phases of P(1) is almost equal to that of the Φmk phase
of m = 1 RH-PBI (3.5 Å).
Unlike P(0) and P(1), P(2) self-organizes into a lamellar-
like arrangement of molecules with a planar single unit re-
peat and extended semifluorinated chains (Figure 3g), de-
noted “Φs–ok” for consistency with other structures in this
work. Close intermolecular π–π stacking of 3.5 Å is evident
XRD patterns and molecular models of the supramolecu-
lar assemblies of the PCl series are shown in Figure 4. Like
P(0) (Figure 3e), PCl(0) adopts a propeller-like molecular
conformation and generates tetramers which self-organize
into a Φc-ok phase (Figure 4e). The π–π stacking distance of
ACS Paragon Plus Environment

Page 9 of 21
ACS Combinatorial Science
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
Figure 5. XRD patterns collected from oriented fibers of the N series (a–d) and schematic illustrations of molecular models of the N
k
series (e–h). Temperature, phase, lattice parameters, layer lines and fiber axis are indicated, as appropriate. Phase notation: Φh
–
columnar hexagonal crystalline phase; Φc–ok – columnar centered orthorhombic crystalline phase; Φs–ok – columnar simple ortho-
rhombic crystalline phase. Color code: green – C, aromatic core; yellow – C, dendron phenyl ring; grey – C, dendron linker; white –
H; red – O; dark blue – N; light blue and orange – semifluorinated chains.
PCl(0) (5.3 Å) is slightly larger than that of P(0) (4.8 Å)
and arises from the increase in the effective volume of the
Cl4PBI core caused by its distortion from planarity. The
thermodynamically controlled formation of a single crystal
phase in P(0) and PCl(0) contrasts both with the mixture of
2D and 3D phases generated by m = 0 RH-PBI82 and with the
mixture of thermodynamically and kinetically 3D phases
generated by m = 0 RH-Cl4PBI.67
PCl(1) exhibits a 3D Φhk phase generated by a kinetically
controlled process in which the helical columns are formed
by single molecules stacked with a π–π distance of 4.0 Å and
rotated by 45° with respect to adjacent molecules (Figure
4f). The enhanced flexibility afforded by the m = 1 linker in
PCl(1) allows the molecules to adopt a more favorable con-
formation and generate closer π–π stacking than in PCl(0)
(5.3 Å). As discussed later, reconstruction of the XRD pat-
tern of PCl(1) suggests that its columns self-organize ac-
cording to the cogwheel mechanism.32
density (1.69 g/cm3, Supporting Table ST5) were unable to
reproduce the experimental XRD pattern satisfactorily, and
therefore the nature of the molecular packing of PCl(3)
could not be determined. The typically observed columnar
structures generated by dendronized PBIs,32,66,67 character-
ized by planar cofacial π–π stacking of aromatic cores, is dis-
rupted in m = 3 derivatives due to the enhanced flexibility
of the longer linker. This gives rise to non-columnar (P(3))
and/or atypical columnar structures (PCl(3)) or, as will be
discussed later, disfavoring the formation of ordered arrays
completely (N(3) and B(3)).
Figure 5 shows XRD patterns and molecular models of the
supramolecular assemblies in the N series. As for P(0) and
PCl(0), N(0) exhibits a single, thermodynamically con-
trolled crystalline phase below Ti. While this phase is a Φc–
k
k
phase for P(0) and PCl(0), for N(0) this is a Φh phase.
o
The helical columns of N(0) are constructed from a single
molecules separated by 5.1 Å (Figure 5e). This is almost
identical to the π–π distances observed in the Φc-ok phase of
P(0) and PCl(0) (5.1 and 5.3 Å, respectively) and arises
from the propeller-like conformation of m = 0 molecules.
PCl(2) and PCl(3) form 2D phases via kinetic control. It
was not possible to determine the structure of the 2D phase
in PCl(2) due to the low degree of order and low Ti of the
compound. The XRD pattern of the ordered array observed
only upon first heating of an as prepared sample of PCl(3)
(Figure 4d) is consistent with a Φhio lattice with an a param-
eter of 31.9 Å. The intense meridional feature suggests a π–
π stacking distance of ~4.2 Å, i.e. slightly higher than that in
PCl(1) (4.0 Å). Unfortunately, XRD simulation studies of
various models of PCl(3) consistent with the experimental
A fiber extruded from an as prepared sample of N(1) at
23 °C exhibits two crystalline phases upon first heating at 2
°C/min: an initially observed Φhk phase (Figure 5b, f) and a
subsequently formed Φc–ok phase (Figure 5c, g).
Cooling and reheating regenerate only Φc–ok, which must
therefore be a kinetically controlled crystalline phase that
ACS Paragon Plus Environment

ACS Combinatorial Science
Page 10 of 21
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
Figure 6. XRD patterns collected from oriented fibers of the B series (a–d) and schematic illustrations of molecular models of the B
series (e–h). In (b), the WAXS pattern on the left was collected at a detector-to-sample distance of 11 cm, and the IAXS pattern on
the right was collected at a detector-to-sample distance of 54 cm. Temperature, phase, lattice parameters, layer lines and fiber axis
are indicated, as appropriate. Phase notation: Φhk – columnar hexagonal crystalline phase; Φmk – columnar monoclinic crystalline
phase; Φs–ok – columnar simple orthorhombic crystalline phase; Φc–ok – columnar centered orthorhombic crystalline phase. Color
code: green – C, aromatic core; yellow – C, dendron phenyl ring; grey – C, dendron linker; white – H; red – O; dark blue – N; light
blue and orange – semifluorinated chains.
represents the thermodynamic product of supramolecu-
lar self-organization. Both phases exhibit close contact (3.4
Å) stacking of aromatic cores. The difference in the stabili-
ties of Φhk and Φc–ok lies in the molecular packing within the
helical columns. In the less favorable Φhk phase, N(1) mole-
cules are stacked with a relative rotation of 60° to each
other. In contrast, heating the sample above 44 °C (Figure
2a) permits rearrangement of the molecules to generate the
Φc–ok phase, in which the intermolecular rotation is 90°. The
columns in both Φh and Φc–o are helical, but are incon-
sistent with the cogwheel model observed for P(1) and
PCl(1) (Supporting Figure SF7). Instead, peripheral chains
on the columns of N(1) are tilted away from the column
axis.
6a, e). However, this crystal is formed via a kinetically con-
trolled process in B(0) whereas P(0), PCl(0), and B(0)
form crystalline phases via thermodynamic controlled pro-
cesses. The Φhk phase generated by B(0) suggests that com-
pounds with smaller aromatic cores (N(0) and B(0)) are
k
able to adopt a higher symmetry structure (Φh ) than com-
pounds with larger cores (P(0) and PCl(0)), which form
pseudohexagonal Φc–ok phases. The Φhk phase of B(0) forms
a pseudohexagonal array of single-column unit cells more
accurately described as a larger hexagonal unit cell contain-
ing four columns with slightly differing projections on the
ab-plane of the lattice. Solid state NMR experiments to be
discussed later supports asymmetric packing in the crystal-
line Φhk phase of B(0) but the exact nature of the difference
between columns could not be ascertained through molec-
ular modeling and XRD simulation studies. The helical col-
k
k
k
N(2) adopts a kinetically controlled Φs–o phase (Figure
5d, h), observable with slow first heating at 2 °C/min or via
an exothermic crystallization at 23 °C upon second heating
at 10 °C/min (Supporting Figure SF1c). N(2) generates a la-
mellar-like arrangement of molecules rather than a colum-
nar structure, denoted “Φs–ok” as for P(2). The molecules in
this phase are separated by a larger distance (5.1 Å) than
those in N(1) (3.5 Å) and identical to the π–π stacking dis-
tance in N(0) (5.1 Å).
k
umn of B(0) in Φh comprises a single unit repeat with an
intermolecular π–π stacking distance of 4.6 Å, i.e. slightly
smaller than in N(0) (5.1 Å) but still consistent with a pro-
peller-like molecular conformation.
k
B(1) exhibits a single kinetically controlled Φm phase
(Figure 6b, f), observable upon first heating (Figure 2b)
k
with similar helical columns to those in Φh of B(0): both
compounds stack in a helical arrangement with a 60° rota-
tion between adjacent molecules and a similar intermolec-
ular distance: 4.5 Å in B(1) vs 4.6 Å in B(0). Furthermore,
As with the other m = 0 compounds discussed here, B(0)
adopts a propeller-like molecular conformation and gener-
ates only a single helical crystalline phase below Ti, (Figure
ACS Paragon Plus Environment

Page 11 of 21
ACS Combinatorial Science
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
k
Figure 7. The cogwheel model of P(1) (a–d) in Φmk2 and of PCl(1) (e–h) in Φh . (a–c) Schematic illustrations of the cogwheel
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
model of P(1) used in the XRD simulation in (d). (d) Comparison of (left) experimental and (right) simulated XRD patterns of P(1).
(e–g) Schematic illustrations of the cogwheel model of PCl(1). (h) Comparison of (left) experimental and (right) reconstructed
XRD patterns of PCl(1). Phases, lattice indexing, temperature and phase are indicated. Phase notation: Φmk2 – columnar simple
monoclinic crystalline phase; Φhk – columnar hexagonal crystalline phase. Dcol, exp represents the column diameter as determined
from lattice parameters calculated from XRD data. Dcol, model represents the column diameter of the supramolecular column as mod-
eled, depicted in (c) and (g) for P(1) and PCl(1), respectively. Color code: green – C, aromatic core; yellow – C, dendron phenyl
ring; grey – C, dendron linker; light blue, orange – semifluorinated chains; white – H; red – O; dark blue – N, imide.
their experimental XRD patterns are best indexed by large,
low symmetry unit cells, but could almost be described by a
unit cell in which the a and b parameters are decreased by
50% to give a unit cell containing a single column. These
unit cells are of almost equal dimensions (Figure 6a, b) and
volumes: 27.2 nm3 in Φmk of B(1) vs 29.2 nm3 in Φhk of B(0).
The key difference between the supramolecular packing of
B(0) and B(1) is the relative conformation of the phenyl
ring of the dendron. The methylene linker in B(1) precludes
a propeller-like conformation, generating instead a crystal-
line array of tilted helical columns.
N(2) than it is for tilted helical structures such as N(1) and
B(1). B(2) also exhibited a crystalline Φs–ok phase in the as
prepared sample (Figure 6c, g), which was not reformed
upon subsequent heating and cooling. This Φs–ok phase is a
lamellar-like arrangement of molecules rather than a true
columnar structure and is denoted “Φs–ok” for consistency.
Supporting Table ST5 summarizes the lattice parameters of
all compounds, determined from fiber XRD experiments.
Detailed structural analysis data are presented in Support-
ing Table ST4.
Molecular Modeling and Reconstruction of the XRD
Patterns of P(1) and PCl(1) with the Cogwheel Model. A
library of dendronized PBIs with m = 1 (denoted PBI*) and
dendrons with three chiral dimethyloctyloxy chains that
self-organize into supramolecular helices via a cogwheel
mechanism was recently reported.32 Simulated XRD pat-
terns generated from cogwheel models of P(1) and PCl(1)
closely reproduce experimentally obtained XRD patterns
(Figure 7), indicating that P(1) and PCl(1) self-organize ac-
cording to the cogwheel model.
Unlike the trend observed in the P, PCl and N series,
which correlates increasing m with decreasing Ti, B(2) (Ti =
96 °C) has a markedly higher Ti than both B(1) (Ti = 45 °C),
which does not self-assemble into any 2D or 3D arrays after
initial melting, and B(0) (Ti = 84 °C), which adopts a ther-
modynamically controlled crystalline Φhk phase (Figure 6a,
e).
The π–π stacking distance in B(2) (3.4 Å) is shorter than
stacking distances in B(0) (4.6 Å) and B(1) (4.5 Å). This
close contact packing was also observed in P(1), P(2), and
N(1), and may be responsible for the enhanced Ti of B(2)
relative to B(0) and B(1). Neighboring molecules in the su-
pramolecular columns of B(2) are rotated by 90° with re-
spect to each other, forming a dimeric unit which repeats
along the column axis. Although the arrangement of aro-
matic cores in columns of B(2) is helical, the small size of its
aromatic core compared to the size of the unit cell (Figure
6h) suggests that the semifluorinated chains of B(2) are ex-
tended far from the column core. This is more typical of la-
mellar-like structures such as those formed by P(2) and
A key criterion for the cogwheel model is the arrange-
ment of peripheral alkyl or semifluorinated chains parallel
to the column axis, thereby acting as the ‘teeth’ of a cog-
wheel.32 The diameters of supramolecular columns of P(1)
and PCl(1) modeled with parallel semifluorinated chains
(Figure 7c, g; Dcol, model = 25.4 Å) reproduce the diameters of
the columns derived from XRD data (Figure 7d, h; Dcol, exp
=
25.3 Å). In contrast, the experimental column diameter of
N(1) (25.4 Å) derived from XRD data is significantly
ACS Paragon Plus Environment

ACS Combinatorial Science
Page 12 of 21
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
Figure 8. (a) Comparison of the supramolecular columns self-assembled from the P, PCl, N, and B series. (b–e) Summary of thermal
phase behavior of periodic arrays as a function of m and temperature for (b) the P series, (c) the PCl series, (d) the N series and (e)
the B series. Data obtained from DSC and XRD upon second heating at indicated heating rate, unless otherwise stated. Formation
process abbreviation: Thermo – thermodynamic; Kin, K – kinetic. Phase notation: Φc–ok – columnar centered orthorhombic crystal-
line phase; Φs–ok – columnar simple orthorhombic crystalline phase; Φhio – 2D columnar hexagonal phase with short range intraco-
lumnar order; Φhk – columnar hexagonal crystalline phase; Φmk – columnar monoclinic crystalline phase; Φx – unidentified disor-
dered phase; Φxk – unidentified crystalline phase. Color code: green – aromatic core; orange, blue – dendron phenyl ring; grey –
dendron linker; pink – Cl atom.
larger than the diameter of a cogwheel column model (21.4
Å), and hence the semifluorinated chains in N(1) must be
tilted away from the column axis (Supporting Figure SF7).
No other compounds in the library of 16 compounds re-
ported here can be described with a physically plausible
model consistent with the cogwheel mechanism. P(1),
PCl(1), and PBI* all have a perylene core, close contact π–π
stacking and a single methylene unit m = 1 linker. This im-
plies that the cogwheel model can be a general mechanism
for columnar self-assembly. These results provide some
tentative parameters for the design of further structures ex-
hibiting a cogwheel structure but additional experiments
are required to enable design of programmed self-organiza-
tion via the cogwheel model.
The cogwheel model allowed PBI* to deracemize at the
supramolecular level.32 The semifluorinated molecules re-
ported here are also chiral but racemic, due to the asymmet-
ric CHF unit in the semifluorinated chain. PCl(1) exhibits a
columnar hexagonal unit cell, and hence deracemization
may occur between supramolecular helices of PCl(1). How-
ever, the inability to access enantiopure semifluorinated
minidendrons precludes experimental investigation into
this process. P(1) forms a monoclinic phase with two col-
umns in its unit cell, and hence columns of different hand-
edness could pack together in the same crystalline domain
in their assemblies.
ACS Paragon Plus Environment

Page 13 of 21
ACS Combinatorial Science
Comparative Analysis of the Complex Supramolecu- Molecules of the N and B series generally exhibit substan-
1
2
3
4
5
6
7
8
lar Assemblies of Semifluorinated PBI, Cl4PBI, NBI, and
PMBI. Figure 8 depicts the supramolecular columnar struc-
tures and phase diagrams of the P, PCl, N, and B series.
Twelve compounds self-organize to give a single molecule
in the strata of their columns. In contrast, P(0) and PCl(0)
contain two molecules per stratum, as seen in RH-PBIs and
RH-Cl4PBIs.67,82 This may arise from the higher electron den-
sity of the semifluorinated segments and consequently
higher electronic repulsion between these segments when
packed together with a column stratum. Helical crystalliza-
tion occurs via thermodynamic control for Φc–ok of P(0) and
PCl(0) and for Φhk of N(0), whereas Φhk is formed via a ki-
netically controlled process in B(0). All m = 0 compounds
generate a single crystalline phase, which contrasts with the
multiple phases observed in RH- PBI82 and RH-Cl4PBI.67 The
propeller-like molecular conformation induces steric hin-
drance between adjacent molecules such that the m = 0
compounds demonstrate the highest π–π stacking distances
within their respective series. However, the intermolecular
spacing in the remaining structures in the P series does not
vary significantly with m (3.4 Å in P(1) and 3.5 Å in P(2)).
These distances correlate well with the shortest intramolec-
ular distances observed in RH-PBI (3.5 Å). For all values of
m, the intermolecular π–π spacing in PCl(m) is greater than
that in P(m), as expected from the disruption to the planar-
ity of the aromatic core in Cl4PBI molecules caused by steric
and electronic repulsions between the chlorine atoms in the
bay-positions.
tially lower Ti values than the P and PCl series (Figure 8d,
e). However, in contrast to the mixture of 2D arrays and 3D
crystalline phases observed in the P and PCl series, all non-
isotropic phases in the molecules of the N and B series are
crystalline. This reduction in overall thermal stability with
concomitant elimination of non-crystalline phases has been
observed in the PCl series and in RH-Cl4PBIs.67 The mole-
cules in the N and B series also have a smaller planar aro-
matic region than PBI derivatives, which reduces π–π inter-
actions and the favorability of non-crystalline phases to
such an extent that they are not observed.
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
Whereas P(0) and PCl(0) stack with π–π distances that
are 1.3–1.7 Å greater than those where m = 1, 2, and 3,
which exhibit near-identical stacking distances to each
other, there is no simple relationship between π–π stacking
distance and linker length, m, in the N and B series. In the B
series, the π–π stacking distance is almost identical in B(0)
and B(1) (4.6 vs 4.5 Å) but is markedly lower in the unex-
pectedly stable B(2) (3.4 Å). In the N series, N(0) and N(2)
exhibit the largest stacking distances (5.1 and 5.2 Å) and
N(1) has the lowest distance in the N series (3.4 Å). It is no-
table that the helical columns of both N(1) and B(2), the
most closely packed structures in their respective series,
are formed from dimers in which molecules are in close con-
tact and rotated by 90° with respect to each other, whereas
the columns of all other periodic arrays formed by mole-
cules in the N and B series consist of single unit repeats with
greater separation between adjacent aromatic cores (Fig-
ure 8a).
All molecules in the PCl series (Figure 8c) exhibit a lower
Ti than molecules in the P series (Figure 8b) with the same
linker length, m, consistent with RH-PBI and RH-Cl4PBI.85,86
Tetrachlorination of RH-PBI had also been observed to in-
crease the crystallinity of their supramolecular assemblies,
such that RH-Cl4PBI with m = 0, 1, and 2, generated solely
crystalline structures.67 P(0) and PCl(0) both form a single
crystalline Φc–ok phase via thermodynamic control. P(1) ex-
hibits two crystalline monoclinic phases at low tempera-
ture, Φmk1 and Φmk2, but transforms into a 2D Φhio structure
upon heating. In contrast, PCl(1) forms only a single crys-
Figure 9 compares the structures of the supramolecular
columns generated by compounds in the P, PCl, N, and B se-
ries. Semifluorinated compounds with m = 0 and 1 form ex-
clusively helical structures. Propeller-like molecular con-
formations (Figure 9b, left) are observed in all m = 0 com-
pounds (blue in Figure 9a). The semifluorinated chains in
propeller-like helical conformations are slightly tilted away
from the column axis. In contrast, the semifluorinated
chains in cogwheel columns (red in Figure 9a) are aligned
parallel to the column axis (Figure 9b, center). The cog-
wheel model is observed only in P(1) and PCl(1), that is,
compounds with an m = 1 linker and large aromatic core.
These traits were observed in PBI* which also assembled
via the cogwheel mechanism.32
k
talline Φh phase below Ti. Hence tetrachlorination of P(1)
provides exclusively crystalline assemblies. This effect is
not observed with longer linker lengths: PCl(2) and PCl(3)
do not form any ordered arrays reformed upon cooling from
an isotropic melt. In contrast, P(2) and P(3) form crystal-
Helical columns, with semifluorinated chains tilted away
from the column axis (tilted helical, green in Figure 9a and
Figure 9b, right) are observed in several phases: the ther-
modynamically controlled high temperature 2D columnar
hexagonal Φhio phases of P(m) with m = 1, 2, and 3, and the
crystalline phases of non-cogwheel m = 1 derivatives N(1)
and B(1). The disruption from a cogwheel model in the P
series is due to increased motion of the semifluorinated
chains in the high temperature Φhio phase, introducing a liq-
uid-like semifluorinated region in the periodic array. In
N(1) and B(1), the smaller aromatic core increases steric
hindrance between semifluorinated chains on neighboring
molecules and forces the dendrons to tilt away from the col-
umn axis.
io
line assemblies at low temperature and 2D Φh phases at
higher temperature, as observed for P(1). This high temper-
ature Φhio phase in P(m) with m = 1, 2, and 3 is formed via
a thermodynamically controlled process. Therefore, all
P(m) compounds generate a thermodynamically controlled
phase, which is a crystalline Φc–ok phase for m = 0 and a 2D
Φhio phase for m = 1, 2, and 3. Tetrachlorination of P(m) pre-
vents the formation of 2D arrays via a thermodynamically
controlled process, instead either promoting formation of
3D arrays (Φc–ok in PCl(0) and Φhk in PCl(1)) or eliminating
the formation of any stable ordered arrays, as in PCl(2) and
PCl(3). PCl(2) and PCl(3) represent examples of electroni-
cally active semifluorinated liquids and glasses, which may
be of interest for applications in special organic electronics.
ACS Paragon Plus Environment

ACS Combinatorial Science
Page 14 of 21
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
Figure 9. (a) Schematic summary of column structure in supramolecular columns self-assembled from the P, PCl, N, and B series.
(b) Structural models to exemplify the three helical mechanisms for self-assembly observed in this work: (left) propeller-like heli-
cal; (center) cogwheel helical; (right) tilted helical. Phase notation: Φc–ok – columnar centered orthorhombic crystalline phase; Φs–
k – columnar simple orthorhombic crystalline phase; Φhio – 2D columnar hexagonal phase with short range intracolumnar order;
o
Φhk – columnar hexagonal crystalline phase; Φmk, Φmk1, Φmk2 – columnar monoclinic crystalline phase; Φx – unidentified disor-
dered phase; Φxk – unidentified crystalline phase; i – isotropic. Color code: green – C, aromatic core; yellow – C, dendron phenyl
ring; grey – C, dendron linker; light blue, orange – semifluorinated chains; white – H; red – O; dark blue – N, imide.
P(2), N(2), and B(2) adopt planar molecular confor-
mations, forming lamellar-like Φs–o phases with extended
semifluorinated chains and a non-helical arrangement of ar-
omatic cores. These phases are characterized by a lack of
rotation between adjacent molecules, and the extension of
semifluorinated chains far from the bisimide core. The Φc–
phase of B(2) (Figure 6h) also has extended semifluori-
nated chains but has a helical arrangement of aromatic
cores with an average intermolecular rotation of 90°. P(3)
and PCl(2) form unidentified phases, while N(3) and B(3)
generate only an electronically active isotropic liquid.
from the PBI core strongly overlap and are observed as a
broad peak with a maximum at 7.9 ppm, indicating signifi-
cantly stronger electronic shielding in the condensed phase
compared to the corresponding site in solution (Figure 10a,
top left; 8.7 and 8.9 ppm). Even the signals from the protons
of the phenyl rings of the dendrons are poorly resolved and
seen only as a shoulder to the core proton signals around
7.0 ppm. In contrast, the protons of the side chains (–OCHF–
) appear as a well resolved peak at 5.9 ppm.
k
k
o
The spectrum of PCl(0) (Figure 10b) shows much better
resolved signals than that of P(0), allowing discrimination
between the protons of the Cl4PBI core at 7.9 ppm and the
protons of the dendron phenyl rings at 7.0 ppm. The in-
creased resolution in PCl(0) vs P(0) indicates a more regu-
lar stacking in Cl4PBI. This supports the higher order assem-
bly observed by XRD experiments and was observed in RH-
Cl4PBIs.67 The position and line shape of the proton signals
from the side chains is unchanged between P(0) and
PCl(0), suggesting that the differences between the two sys-
tems originate only from the different stacking of the
twisted molecular Cl4PBI building blocks compared to that
of the planar PBI molecules. This agrees with molecular
models reconstructed from XRD data which suggest a simi-
lar helical columnar structure in P(0) and PCl(0) compris-
ing a tetrameric repeating unit with two molecules per col-
umn stratum of thickness 5.1 and 5.3 Å, respectively (Figure
8a).
Solid State NMR Studies of Dendronized PBI, Cl4PBI,
and NBI. Solid state NMR experiments are able to verify and
refine models derived from XRD results by interrogating the
structure of supramolecular assemblies at a molecular level,
and provide additional information about dynamic pro-
cesses not available via diffraction experiments, such as lo-
cal molecular reorientation within supramolecular struc-
tures.94,95 In particular, proximity of aromatic groups such
1
as in columnar stacks leads to characteristic H NMR shifts
in bulk compared to the chemical shifts in solution. Figure
1
10 shows excerpts of H Magic Angle Spinning (MAS) NMR
spectra of dendronized P(m), PCl(m) and N(m) with m = 0
and 1, recorded at 50 °C. Solution NMR spectra recorded in
CDCl3 at 27 °C are provided for comparison. Spectra of B(0)
are shown in Supporting Figure SF8.
P(m), PCl(m), and N(m) are expected to exhibit rela-
1
tively simple H MAS spectra due to the low number of
The signal arising from the core protons of N(0) (Figure
10b, top right) is broader than the analogous signal for P(0)
and PCl(0), ranging from 9.5 to 7.3 ppm with a weighted av-
erage of 8.1 ppm. Weak features at the top of the signal can-
1
chemically distinct H environments observed in solution
NMR spectra (Figure 10a): m + 4 environments for P(m)
and m + 3 environments for PCl(m) and N(m). However,
self-organization of the molecules in the solid state leads to
a substantial spread of the chemical shifts, determined by
the heterogeneity of the local packing arrangement. For
P(0) (Figure 10b, top left), the two signals expected to arise
1
not be interpreted based on the H MAS NMR spectrum
alone. In contrast to the broad signal of the core protons, the
signals arising from the dendron phenyl rings and the sem-
ifluorinated side chains are relatively sharp, at 7.2 and 5.8
ACS Paragon Plus Environment

Page 15 of 21
ACS Combinatorial Science
ppm, respectively. The proton of the semifluorinated side is the narrow Lorentzian line shape of the signal arising
1
2
3
4
5
6
7
8
group is better separated from the aromatic proton signals
in N(0) than in P(0) or PCl(0), perhaps due to the smaller
π-electron system and consequently weaker π-electron
shifts of the NBI core.
from the core protons at 7.6 ppm, indicating more regular
packing in N(1) than in N(0). This observation is consistent
with the much closer π–π stacking in N(1) vs N(0) (3.4 vs
5.1 Å) and significantly lower density of N(0) at 23 °C
(1.38 g/cm3 vs 1.71 g/cm3 for N(1)). This may result from
the ability of the dendron to tilt out of the stratal plane in
N(1), due to the presence of the methylene linker (Figure
5). In all cases, the addition of a methylene unit from m = 0
to m = 1 causes a downfield shift of the proton signal of the
semifluorinated side chain by 0.2–0.3 ppm. This feature
cannot directly be attributed to the improved π–π stacking
in the m = 1 compounds, but might arise from local changes
in the density of the semifluorinated groups required to ac-
commodate the improved stacking of the aromatic cores.
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
More detailed information on the local packing arrange-
ment of molecules in the supramolecular structure can be
obtained by 2D 1H–1H Double Quantum (DQ) NMR correla-
tion spectra, which probe proximities between specific pro-
ton sites.94,95 Examples are shown for P(m), PCl(m) and
N(m) with m = 0 and 1 in Figure 11 and for B(0) in Support-
ing Figure SF8. The multitude of structured features in the
aromatic region of these spectra evidences the presence of
differently ordered stacks in these samples.
The DQ-SQ correlation spectrum of P(0) (Figure 11a) is
unstructured, indicating a broad variety of local packing ar-
rangements of neighboring PBI cores. Sharp features result
from DQ coherences involving protons of the semifluori-
nated chains. Coherences between two CHF protons of the
semifluorinated chains are observed at 5.8 ppm/11.6 ppm
(broken red circle), while coherences between CHF sites
and aromatic protons are observed at 5.8 ppm/13.7 ppm
(broken red line). The DQ-SQ correlation spectrum of
PCl(0) (Figure 11b) shows many more detailed features
compared to the spectrum of P(0). In addition to the DQ co-
herence between two CHF sites at 5.8 ppm/11.6 ppm (bro-
ken orange circle), coherences of these sites with the pro-
tons of the core (5.8ppm/13.8 ppm and 8 ppm/13.8 ppm,
lower broken orange line) as well as with the protons of the
dendron phenyl rings (5.8 ppm/12.8 ppm and 7 ppm/12.8
ppm, upper broken orange line) are observed. The correla-
tion pattern between the aromatic moieties of PCl(0) (par-
allel to the diagonal) is also much more structured com-
pared to that of P(0). Higher resolution in the spectrum of
tetrachlorinated PCl(0) compared to that of nonchlorinated
P(0) was also observed for RH-PBI and RH-Cl4PBI.67
1
1
Figure 10. (a) H solution NMR spectra and (b) H Magic
Angle Spinning (MAS) NMR spectra of P(m) (left), PCl(m)
(center), and N(m) (right), with m = 0 (top) and 1 (bottom).
Solution spectra were recorded at 27 °C in THF-d8 (P(0)) or
CDCl3 (all others), and residual solvent peaks are marked
with a red cross. Solid state MAS spectra were recorded at
50°C with a MAS spinning frequency of 25 kHz.
Some general trends are evident upon comparison of the
1H MAS NMR spectra of the m = 0 compounds (Figure 10,
top) with those of the m = 1 derivatives (Figure 10, bottom).
In all cases, the proton signal of the aromatic core moiety
becomes significantly narrower and more shielded upon
addition of a methylene linker due to improved π–π stack-
ing of the aromatic core moieties in the m = 1 compounds.
This agrees with the closer stacking evidenced by XRD (Fig-
ures 3 and 4). In P(1) and PCl(1), this shift is so pronounced
that the signals of the dendron phenyl rings and those of the
semifluorinated chains overlap and cannot be distin-
guished. In the spectrum of N(1), the signals from the NBI
core and the dendron phenyl rings are well resolved, and
are both shifted upfield by 0.5 ppm compared to similar sig-
nals in N(0). Of particular interest in the spectrum of N(1)
N(0) also exhibits a dominant DQ signal in the aromatic
region (Figure 11c), where the core protons have become
inequivalent due to the local environment. A DQ signal in-
volving two protons from the semifluorinated chains is ob-
served in N(0) (broken blue circle), as in P(0) and PCl(0).
In addition, DQ coherences between the CHF sites and the
core protons (5.8–8.0 ppm/13.8 ppm, lower broken blue
line) as well as between the CHF sites and the dendron phe-
nyl ring protons (5.8–7.2 ppm/13.0 ppm, upper broken blue
line) are observed, the latter being of significantly higher in-
tensity.
ACS Paragon Plus Environment

ACS Combinatorial Science
Page 16 of 21
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
Figure 11. 2D 1H–1H Double Quantum (DQ) NMR correlation spectra of (a) P(0), (b) PCl(0), (c) N(0), (d) P(1), (e) PCl(1), and (f)
N(1) recorded at 50 °C with a MAS spinning frequency of 25 kHz and DQ excitation period of one rotor period using the Back-to-
Back DQ excitation scheme. Broken lines and circles denote features of interest, described in the main text.
An additional DQ signal is observed in the spectra of the
m = 1 compounds (Figure 11d–f) arising from the meth-
ylene protons. It should be noted that the two protons of the
methylene linker are inequivalent and exhibit two signals
separated by up to 0.9 ppm (in PCl(1) and N(1)). Further-
more, the DQ spectrum of N(1) indicates the presence of
two different packing arrangements (broken vs. solid lines)
with different electronic shielding from the aromatic moie-
ties, such that the more shielded CH2 signals (broken blue
lines) correlate with the core proton signals with higher
chemical shift values and thus weaker π–π interactions. The
presence of two different packing arrangements is con-
sistent with DSC data (Figure 2a) which indicate a transition
Conclusions
The synthesis, structural, and retrostructural analysis of
a “combined generational” library of sixteen semifluori-
nated dendronized aromatic bisimides based on PBI, Cl4PBI,
NBI, and PMBI with various lengths of aliphatic linker m (m
= 0, 1, 2, and 3) is reported. Thermodynamically controlled
formation of crystalline phases is observed for the first time
in m = 0 arylene derivatives (P(0), PCl(0), and N(0)), and
three PBI derivatives (P(1), P(2), and P(3)) undergo ther-
io
modynamically controlled self-assembly to form a 2D Φh
phase at high temperature. Two molecules (P(1) and
PCl(1)) assemble via a cogwheel model and provide design
parameters to generalize programmed cogwheel assembly
in additional systems. Semifluorinated electronically active
liquids and glasses are formed by five molecules (PCl(2),
PCl(3), N(3), B(1), and B(3)) upon second and subsequent
heating of the as prepared sample. These liquids and glasses
may have desirable properties for numerous applications
including organic electronics. This diversity of assemblies
could only be accessed by screening rationally designed li-
braries of self-assembling semifluorinated dendronized ar-
omatic bisimides. These library approaches will continue to
elucidate the influence of molecular parameters and pri-
mary structure on the generation of order at the supramo-
lecular level and will therefore enable the design, from first
principles, of further thermodynamically controlled and
thermally accessible structures with potential technological
applications such as coatings, dyestuffs, and organic elec-
tronics.
k
k
between the Φh and Φc–o phases of N(1) occurring at the
NMR experimental temperature of 50 °C.
The m = 0 compounds all exhibit a spread of the DQ sig-
nals between the core protons and the dendron phenyl ring
protons along the diagonal of the spectrum (Figure 11a–c).
This spread indicates a heterogeneous distribution of π–π
interactions within a similar packing arrangement of aro-
matic core and dendron phenyl ring. In PCl(1) and N(1)
(Figure 11e, f), this spreading collapses to a single, well-de-
fined π-stacking distance, indicating a more highly ordered
structure in these m = 1 derivatives. In contrast, the DQ
spectrum of P(1) (Figure 11d) is still blurred, with a notable
spread of the aromatic core/dendron phenyl correlation
signals distributed along the spectral diagonal. Neverthe-
less, the local packing of the PBI core moiety is clearly im-
proved upon the addition of the methylene linker, con-
1
sistent with H MAS spectra (Figure 10b) and XRD results
(Figure 3a, b).
ACS Paragon Plus Environment

Page 17 of 21
ACS Combinatorial Science
Perylenediimide Chromophores. J. Am. Chem. Soc. 2004, 126 (39),
12268–12269.
ASSOCIATED CONTENT
1
2
3
4
5
6
Experimental procedures, synthetic protocols, characteriza-
tion data for new compounds and additional discussion are
available in the Supporting Information. This material is avail-
able free of charge via the Internet at http://pubs.acs.org.
(14) Zhang, X.; Rehm, S.; Safont-Sempere, M. M.; Würthner, F.
Vesicular Perylene Dye Nanocapsules as Supramolecular
Fluorescent pH Sensor Systems. Nat. Chem. 2009, 1 (8), 623–629.
(15) Wasielewski, M. R. Self-Assembly Strategies for
Integrating Light Photosynthetic Systems. Acc. Chem. Res. 2009, 42
(12), 1910–1921.
AUTHOR INFORMATION
(16) Eakins, G. L.; Gallaher, J. K.; Keyzers, R. A.; Falber, A.;
Webb, J. E. A.; Laos, A.; Tidhar, Y.; Weissman, H.; Rybtchinski, B.;
Thordarson, P.; Hodgkiss, J. M. Thermodynamic Factors Impacting
the Peptide-Driven Self-Assembly of Perylene Diimide Nanofibers.
J. Phys. Chem. B 2014, 118, 8642–8651.
(17) Krieg, E.; Weissman, H.; Shimoni, E.; Bar On Ustinov, A.;
Rybtchinski, B. Understanding the Effect of Fluorocarbons in
7
8
9
Corresponding Author
* E-mail: percec@sas.upenn.edu
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
ACKNOWLEDGMENT
Financial support by the National Science Foundation (DMR-
1066116 (VP), DMR-1120901 (VP and PAH) and
OISE-1243313 (VP)), the Humboldt Foundation (VP) and the P.
Roy Vagelos Chair at Penn (VP) is gratefully acknowledged. GU
and XZ acknowledge support from the joint NSF-EPSRC PIRE
project “RENEW” (EPSRC grant EP-K034308). BEP thanks the
Howard Hughes Medical Institute for an International Student
Research Fellowship.
Aqueous
Supramolecular
Polymerization:
Ultrastrong
Noncovalent Binding and Cooperativity. J. Am. Chem. Soc. 2014,
136 (26), 9443–9452.
(18) Krieg, E.; Bastings, M. M. C.; Besenius, P.; Rybtchinski, B.
Supramolecular Polymers in Aqueous Media. Chem. Rev. 2016, 16,
2414–2477.
(19) Anthony, J. E.; Facchetti, A.; Heeney, M.; Marder, S. R.;
Zhan, X. N-Type Organic Semiconductors in Organic Electronics.
Adv. Mater. 2010, 22 (34), 3876–3892.
(20) Zhan, X.; Facchetti, A.; Barlow, S.; Marks, T. J.; Ratner, M.
A.; Wasielewski, M. R.; Marder, S. R. Rylene and Related Diimides
for Organic Electronics. Adv. Mater. 2011, 23, 268–284.
(21) Facchetti, A. π-Conjugated Polymers for Organic
Electronics and Photovoltaic Cell Applications. Chem. Mater. 2011,
23 (3), 733–758.
(22) Tsarfati, Y.; Strauss, V.; Kuhri, S.; Krieg, E.; Weissman, H.;
Shimoni, E.; Baram, J.; Guldi, D. M.; Rybtchinski, B. Dispersing
Perylene Diimide/SWCNT Hybrids: Structural Insights at the
Molecular Level and Fabricating Advanced Materials. J. Am. Chem.
Soc. 2015, 137 (23), 7429–7440.
(23) Shahar, C.; Dutta, S.; Weissman, H.; Shimon, L. J. W.; Ott,
H.; Rybtchinski, B. Precrystalline Aggregates Enable Control over
Organic Crystallization in Solution. Angew. Chem. Int. Ed. 2016, 55
(1), 179–182.
(24) Hartnett, P. E.; Margulies, E. A.; Matte, H. S. S. R.; Hersam,
M. C.; Marks, T. J.; Wasielewski, M. R. Effects of Crystalline
Perylenediimide Acceptor Morphology on Optoelectronic
Properties and Device Performance. Chem. Mater. 2016, 28 (11),
3928–3936.
(25) Görl, D.; Würthner, F. Entropically Driven Self-Assembly
of Bolaamphiphilic Perylene Dyes in Water. Angew. Chem. Int. Ed.
2016, 55, 12094–12098.
(26) Ogi, S.; Stepanenko, V.; Thein, J.; Würthner, F. Impact of
Alkyl Spacer Length on Aggregation Pathways in Kinetically
Controlled Supramolecular Polymerization. J. Am. Chem. Soc. 2016,
138 (2), 670–678.
(27) Sung, J.; Nowak-Król, A.; Schlosser, F.; Fimmel, B.; Kim,
W.; Kim, D.; Würthner, F. Direct Observation of Excimer-Mediated
Intramolecular Electron Transfer in a Cofacially Stacked Perylene
Bisimide Pair. J. Am. Chem. Soc. 2016, 138, 9029–9032.
(28) Fernandez-Ariza, J.; Calderon, R. M. K.; Rodriguez-
Morgade, M. S.; Guldi, D. M.; Torres, T. Phthalocyanine-
Perylenediimide Cart Wheels. J. Am. Chem. Soc. 2016, 138 (39),
12963–12974.
(29) Fan, Y.; Barlow, S.; Zhang, S.; Lin, B.; Marder, S. R.
Comparison of 3D Non-Fullerene Acceptors for Organic
Photovoltaics Based on Naphthalene Diimide and Perylene
Diimide-Substituted 9,9′-Bifluorenylidene. RSC Adv. 2016, 6 (74),
70493–70500.
(30) Erdmann, T.; Fabiano, S.; Milián-Medina, B.; Hanifi, D.;
Chen, Z.; Berggren, M.; Gierschner, J.; Salleo, A.; Kiriy, A.; Voit, B.;
Facchetti, A. Naphthalenediimide Polymers with Finely Tuned in-
REFERENCES
(1)
Würthner, F. Perylene Bisimide Dyes as Versatile
Building Blocks for Functional Supramolecular Architectures.
Chem. Commun. 2004, 1564–1579.
(2)
Rosen, B. M.; Wilson, C. J.; Wilson, D. A.; Peterca, M.;
Imam, M. R.; Percec, V. Dendron-Mediated Self-Assembly,
Disassembly, and Self-Organization of Complex Systems. Chem.
Rev. 2009, 109 (11), 6275–6540.
(3)
Huang, C.; Barlow, S.; Marder, S. R. Perylene-3,4,9,10-
Tetracarboxylic Acid Diimides: Synthesis, Physical Properties, and
Use in Organic Electronics. J. Org. Chem. 2011, 76 (8), 2386–2407.
(4)
Görl, D.; Zhang, X.; Würthner, F. Molecular Assemblies of
Perylene Bisimide Dyes in Water. Angew. Chem. Int. Ed. 2012, 51
(26), 6328–6348.
(5)
Würthner, F.; Saha-Möller, C. R.; Fimmel, B.; Ogi, S.;
Leowanawat, P.; Schmidt, D. Perylene Bisimide Dye Assemblies as
Archetype Functional Supramolecular Materials. Chem. Rev. 2016,
116 (3), 962–1052.
(6)
Wöhrle, T.; Wurzbach, I.; Kirres, J.; Kostidou, A.;
Kapernaum, N.; Litterscheidt, J.; Haenle, J. C.; Staffeld, P.; Baro, A.;
Giesselmann, F.; Laschat, S. Discotic Liquid Crystals. Chem. Rev.
2016, 116 (3), 1139–1241.
(7)
Hammer, B. A. G.; Müllen, K. Dimensional Evolution of
Polyphenylenes: Expanding in All Directions. Chem. Rev. 2016, 116
(4), 2103–2140.
(8)
Gsänger, M.; Bialas, D.; Huang, L.; Stolte, M.; Würthner, F.
Organic Semiconductors Based on Dyes and Color Pigments. Adv.
Mater. 2016, 28, 3615–3645.
(9)
Suraru, S.-L.; Würthner, F. Strategies for the Synthesis of
Functional Naphthalene Diimides. Angew. Chem. Int. Ed. 2014,
7428–7448.
(10) Zheng, Q.; Huang, J.; Sarjeant, A.; Katz, H. E. Pyromellitic
Diimides: Minimal Cores for High Mobility N-Channel Transistor
Semiconductors. J. Am. Chem. Soc. 2008, 130, 14410–14411.
(11) Sydlik, S. A.; Chen, Z.; Swager, T. M. Triptycene
Polyimides: Soluble Polymers with High Thermal Stability and Low
Refractive Indices. Macromolecules 2011, 44 (4), 976–980.
(12) Guo, X.; Watson, M. D. Pyromellitic Diimide-Based Donor-
Acceptor Poly(phenylene Ethynylene)s. Macromolecules 2011, 44,
6711–6716.
(13) Rybtchinski, B.; Sinks, L. E.; Wasielewski, M. R.
Combining Light-Harvesting and Charge Separation in a Self-
Assembled Artificial Photosynthetic System Based on
17
ACS Paragon Plus Environment

ACS Combinatorial Science
Page 18 of 21
Chain π-Conjugation: Electronic Structure, Film Microstructure,
and Charge Transport Properties. Adv. Mater., published online
August 30, 2016; DOI: 10.1002/adma.201602923.
Reverse Thermal Actuators. J. Am. Chem. Soc. 2012, 134 (9), 4408–
4420.
(46) Percec, V.; Glodde, M.; Bera, T. K.; Miura, Y.;
1
2
3
4
5
6
7
8
9
(31) Percec, V.; Sun, H.-J.; Leowanawat, P.; Peterca, M.; Graf, R.;
Spiess, H. W.; Zeng, X.; Ungar, G.; Heiney, P. A. Transformation from
Kinetically into Thermodynamically Controlled Self-Organization
of Complex Helical Columns with 3D Periodicity Assembled from
Dendronized Perylene Bisimides. J. Am. Chem. Soc. 2013, 135,
4129–4148.
(32) Roche, C.; Sun, H.-J.; Leowanawat, P.; Araoka, F.;
Partridge, B. E.; Peterca, M.; Wilson, D. A.; Prendergast, M. E.;
Heiney, P. A.; Graf, R.; Spiess, H. W.; Zeng, X.; Ungar, G.; Percec, V. A
Supramolecular Helix That Disregards Chirality. Nat. Chem. 2016,
8 (1), 80–89.
Shiyanovskaya, I.; Singer, K. D.; Balagurusamy, V. S. K.; Heiney, P.
A.; Schnell, I.; Rapp, A.; Spiess, H.-W.; Hudson, S. D.; Duan, H. Self-
Organization of Supramolecular Helical Dendrimers into Complex
Electronic Materials. Nature 2002, 419, 384–387.
(47) Percec, V.; Wilson, D. A.; Leowanawat, P.; Wilson, C. J.;
Hughes, A. D.; Kaucher, M. S.; Hammer, D. A.; Levine, D. H.; Kim, A.
J.; Bates, F. S.; Davis, K. P.; Lodge, T. P.; Klein, M. L.; DeVane, R. H.;
Aqad, E.; Rosen, B. M.; Argintaru, A. O.; Sienkowska, M. J.; Rissanen,
K.; Nummelin, S.; Ropponen, J. Self-Assembly of Janus Dendrimers
into Uniform Dendrimersomes and Other Complex Architectures.
Science 2010, 328, 1009–1015.
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
(33) Peterca, M.; Percec, V.; Imam, M. R.; Leowanawat, P.;
Morimitsu, K.; Heiney, P. A. Molecular Structure of Helical
Supramolecular Dendrimers. J. Am. Chem. Soc. 2008, 130 (44),
14840–14852.
(34) Sun, H.-J.; Zhang, S.; Percec, V. From Structure to Function
via Complex Supramolecular Dendrimer Systems. Chem. Soc. Rev.
2015, 44, 3900–3923.
(35) Thota, B. N. S.; Urner, L. H.; Haag, R. Supramolecular
Architectures of Dendritic Amphiphiles in Water. Chem. Rev. 2016,
116, 2079–2102.
(36) Lehn, J.-M. Toward Complex Matter: Supramolecular
Chemistry and Self-Organization. Proc. Natl Acad. Sci. USA 2002, 99
(8), 4763–4768.
(37) Percec, V.; Cho, W.-D.; Ungar, G.; Yeardley, D. J. P.
Synthesis and Structural Analysis of Two Constitutional Isomeric
Libraries of AB2 -Based Monodendrons and Supramolecular
Dendrimers. J. Am. Chem. Soc. 2001, 123, 1302–1315.
(38) Percec, V.; Peterca, M.; Sienkowska, M. J.; Ilies, M. A.;
Aqad, E.; Smidrkal, J.; Heiney, P. A. Synthesis and Retrostructural
Analysis of Libraries of AB3 and Constitutional Isomeric AB2
Phenylpropyl Ether-Based Supramolecular Dendrimers. J. Am.
Chem. Soc. 2006, 128, 3324–3334.
(39) Percec, V.; Won, B. C.; Peterca, M.; Heiney, P. A. Expanding
the Structural Diversity of Self-Assembling Dendrons and
Supramolecular Dendrimers via Complex Building Blocks. J. Am.
Chem. Soc. 2007, 129 (36), 11265–11278.
(40) Rosen, B. M.; Wilson, D. A; Wilson, C. J.; Peterca, M.; Won,
B. C.; Huang, C.; Lipski, L. R.; Zeng, X.; Ungar, G.; Heiney, P. A; Percec,
V. Predicting the Structure of Supramolecular Dendrimers via the
Analysis of Libraries of AB3 and Constitutional Isomeric AB2
Biphenylpropyl Ether Self-Assembling Dendrons. J. Am. Chem. Soc.
2009, 131 (47), 17500–17521.
(41) Percec, V.; Mitchell, C. M.; Cho, W. D.; Uchida, S.; Glodde,
M.; Ungar, G.; Zeng, X.; Liu, Y.; Balagurusamy, V. S. K.; Heiney, P. A.
Designing Libraries of First Generation AB3 and AB2 Self-
Assembling Dendrons via the Primary Structure Generated from
Combinations of (AB)y-AB3 and (AB)y-AB2 Building Blocks. J. Am.
Chem. Soc. 2004, 126 (2), 6078–6094.
(48) Peterca, M.; Percec, V.; Leowanawat, P.; Bertin, A.
Predicting the Size and Properties of Dendrimersomes from the
Lamellar Structure of Their Amphiphilic Janus Dendrimers. J. Am.
Chem. Soc. 2011, 133 (50), 20507–20520.
(49) Percec, V.; Leowanawat, P.; Sun, H.-J.; Kulikov, O.;
Nusbaum, C. D.; Tran, T. M.; Bertin, A.; Wilson, D. A.; Peterca, M.;
Zhang, S.; Kamat, N. P.; Vargo, K.; Moock, D.; Johnston, E. D.;
Hammer, D. A.; Pochan, D. J.; Chen, Y.; Chabre, Y. M.; Shiao, T. C.;
Bergeron-Brlek, M.; André, S.; Roy, R.; Gabius, H.-J.; Heiney, P. A.
Modular Synthesis of Amphiphilic Janus Glycodendrimers and
Their Self-Assembly into Glycodendrimersomes and Other
Complex Architectures with Bioactivity to Biomedically Relevant
Lectins. J. Am. Chem. Soc. 2013, 135 (24), 9055–9077.
(50) Zhang, S.; Xiao, Q.; Sherman, S. E.; Muncan, A.; Ramos
Vicente, A. D. M.; Wang, Z.; Hammer, D. A.; Williams, D.; Chen, Y.;
Pochan, D. J.; Vértesy, S.; André, S.; Klein, M. L.; Gabius, H.-J.; Percec,
V. Glycodendrimersomes from Sequence-Defined Janus
Glycodendrimers Reveal High Activity and Sensor Capacity for the
Agglutination by Natural Variants of Human Lectins. J. Am. Chem.
Soc. 2015, 137 (1), 13334–13344.
(51) Xiao, Q.; Zhang, S.; Wang, Z.; Sherman, S. E.; Moussodia,
R.-O.; Peterca, M.; Muncan, A.; Williams, D. R.; Hammer, D. A.;
Vértesy, S.; André, S.; Gabius, H.-J.; Klein, M. L.; Percec, V. Onion-like
Glycodendrimersomes
from
Sequence-Defined
Janus
Glycodendrimers and Influence of Architecture on Reactivity to a
Lectin. Proc. Natl Acad. Sci. USA 2016, 113 (5), 1162–1167.
(52) Roche, C.; Sun, H.-J.; Prendergast, M. E.; Leowanawat, P.;
Partridge, B. E.; Heiney, P. A.; Araoka, F.; Graf, R.; Spiess, H. W.; Zeng,
X.; Ungar, G.; Percec, V. Homochiral Columns Constructed by Chiral
Self-Sorting During Supramolecular Helical Organization of Hat-
Shaped Molecules. J. Am. Chem. Soc. 2014, 136, 7169–7185.
(53) Percec, V.; Ahn, C.-H.; Ungar, G.; Yeardley, D. J. P.; Möller,
M.; Sheiko, S. S. Controlling Polymer Shape through the Self-
Assembly of Dendritic Side-Groups. Nature 1998, 391, 161–164.
(54) Bates, F. S.; Hillmyer, M. A.; Lodge, T. P.; Bates, C. M.;
Delaney, K. T.; Fredrickson, G. H. Multiblock Polymers: Panacea or
Pandora’s Box? Science 2012, 336, 434–440.
(55) Lee, S.; Leighton, C.; Bates, F. S. Sphericity and Symmetry
Breaking in the Formation of Frank–Kasper Phases from One
Component Materials. Proc. Natl. Acad. Sci. 2014, 111 (50), 17723–
17731.
(56) Huang, M.; Hsu, C.-H.; Wang, J.; Mei, S.; Dong, X.; Li, Y.; Li,
M.; Liu, H.; Zhang, W.; Aida, T.; Zhang, W.-B.; Yue, K.; Cheng, S. Z. D.
Selective Assemblies of Giant Tetrahedra via Precisely Controlled
Positional Interactions. Science 2015, 348 (6233), 424–428.
(57) Zhang, W.; Huang, M.; Su, H.; Zhang, S.; Yue, K.; Dong, X.-
H.; Li, X.; Liu, H.; Zhang, S.; Wesdemiotis, C.; Lotz, B.; Zhang, W.-B.;
Li, Y.; Cheng, S. Z. D. Toward Controlled Hierarchical
Heterogeneities in Giant Molecules with Precisely Arranged Nano
Building Blocks. ACS Cent. Sci. 2016, 2 (1), 48–54.
(42) Rosen, B. M.; Peterca, M.; Huang, C.; Zeng, X.; Ungar, G.;
Percec, V. Deconstruction as a Strategy for the Design of Libraries
of Self-Assembling Dendrons. Angew. Chem. Int. Ed. 2010, 49 (39),
7002–7005.
(43) Percec, V.; Dulcey, A. E.; Peterca, M.; Ilies, M.; Nummelin,
S.; Sienkowska, M. J.; Heiney, P. A. Principles of Self-Assembly of
Helical Pores from Dendritic Dipeptides. Proc. Natl Acad. Sci. USA
2006, 103 (8), 2518–2523.
(44) Percec, V.; Rudick, J. G.; Peterca, M.; Heiney, P. A.
Nanomechanical Function from Self-Organizable Dendronized
Helical Polyphenylacetylenes. J. Am. Chem. Soc. 2008, 130, 7503–
7508.
(45) Percec, V.; Imam, M. R.; Peterca, M.; Leowanawat, P. Self-
Organizable Vesicular Columns Assembled from Polymers
Dendronized with Semifluorinated Janus Dendrimers Act As
(58) Perroni, D. V; Mahanthappa, M. K. Inverse Pm3n Cubic
Micellar Lyotropic Phases from Zwitterionic Triazolium Gemini
Surfactants. Soft Matter 2013, 9 (33), 7919–7922.
18
ACS Paragon Plus Environment

Page 19 of 21
ACS Combinatorial Science
(59) Ziherl, P.; Kamien, R. D. Maximizing Entropy by
Minimizing Area: Towards a New Principle of Self-Organization. J.
Phys. Chem. B 2001, 105 (42), 10147–10158.
(60) Snir, Y.; Kamien, R. D. Entropically Driven Helix
Formation. Science 2005, 307, 1067–1067.
Baumgart, T.; Vinogradov, S. A.; Klein, M. L.; Percec, V. Self-Sorting
and Coassembly of Fluorinated, Hydrogenated, and Hybrid Janus
Dendrimers into Dendrimersomes. J. Am. Chem. Soc. 2016, 138
(38), 12655–12663.
1
2
3
(75) Kissa, E. Fluorinated Surfactants and Repellents; Marcel
4
5
6
7
8
9
(61) Li, Y.; Lin, S.; Goddard III, W. A. Efficiency of Various
Lattices from Hard Ball to Soft Ball: Theoretical Study of
Thermodynamic Properties of Dendrimer Liquid Crystal from
Atomistic Simulation. J. Am. Chem. Soc. 2004, 126, 1872–1885.
(62) Glotzer, S. C.; Solomon, M. J. Anisotropy of Building
Blocks and Their Assembly into Complex Structures. Nat. Mater.
2007, 6 (7), 557–562.
(63) Engel, M.; Damasceno, P. F.; Phillips, C. L.; Glotzer, S. C.
Computational Self-Assembly of a One-Component Icosahedral
Quasicrystal. Nat. Mater. 2015, 14 (1), 109–116.
(64) Percec, V.; Peterca, M.; Tadjiev, T.; Zeng, X.; Ungar, G.;
Leowanawat, P.; Aqad, E.; Imam, M. R.; Rosen, B. M.; Akbey, U.; Graf,
R.; Sekharan, S.; Sebastiani, D.; Spiess, H. W.; Heiney, P. A.; Hudson,
S. D. Self-Assembly of Dendronized Perylene Bisimides into
Complex Helical Columns. J. Am. Chem. Soc. 2011, 133 (31), 12197–
12219.
(65) Percec, V.; Hudson, S. D.; Peterca, M.; Leowanawat, P.;
Aqad, E.; Graf, R.; Spiess, H. W.; Zeng, X.; Ungar, G.; Heiney, P. A. Self-
Repairing Complex Helical Columns Generated via Kinetically
Controlled Self-Assembly of Dendronized Perylene Bisimides. J.
Am. Chem. Soc. 2011, 133 (45), 18479–18494.
Dekker, Inc.: New York, 2001.
(76) Renner, R. Growing Concern Over Perfluorinated
Chemicals. Environ. Sci. Technol. 2001, 35 (7), 154A–160A.
(77) Renner, R. Sorting out Sources of Perfluorinated
Chemicals. Environ. Sci. Technol. 2006, 40 (9), 2866–2867.
(78) Guo, J.; Resnick, P.; Efimenko, K.; Genzer, J.; DeSimone, J.
M. Alternative Fluoropolymers to Avoid the Challenges Associated
with Perfluorooctanoic Acid. Ind. Eng. Chem. Res. 2007, 47 (3),
502–508.
(79) Zhang, W. Green Chemistry Aspects of Fluorous
Techniques-Opportunities and Challenges for Small-Scale Organic
Synthesis. Green Chem. 2009, 11 (7), 911–920.
(80) Fiuza, S. M.; Gomes, C.; Teixeira, L. J.; Girão da Cruz, M. T.;
Cordeiro, M. N. D. S.; Milhazes, N.; Borges, F.; Marques, M. P. M.
Phenolic Acid Derivatives with Potential Anticancer Properties–a
Structure-Activity Relationship Study. Part 1: Methyl, Propyl and
Octyl Esters of Caffeic and Gallic Acids. Bioorg. Med. Chem. 2004, 12
(13), 3581–3589.
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
(81) Bertin, A.; Steibel, J.; Michou-Gallani, A.-I.; Gallani, J.-L.;
Felder-Flesch, D. Development of
a Dendritic Manganese-
Enhanced Magnetic Resonance Imaging (MEMRI) Contrast Agent:
Synthesis, Toxicity (in Vitro) and Relaxivity (in Vitro, in Vivo)
Studies. Bioconjug. Chem. 2009, 20 (4), 760–767.
(82) Percec, V.; Peterca, M.; Tadjiev, T.; Zeng, X.; Ungar, G.;
Leowanawat, P.; Aqad, E.; Imam, M. R.; Rosen, B. M.; Akbey, U.; Graf,
R.; Sekharan, S.; Sebastiani, D.; Spiess, H. W.; Heiney, P. A.; Hudson,
S. D. Self-Assembly of Dendronized Perylene Bisimides into
Complex Helical Columns. J. Am. Chem. Soc. 2011, 133, 12197–
12219.
(83) Percec, V.; Hudson, S. D.; Peterca, M.; Leowanawat, P.;
Aqad, E.; Graf, R.; Spiess, H. W.; Zeng, X.; Ungar, G.; Heiney, P. A. Self-
Repairing Complex Helical Columns Generated via Kinetically
Controlled Self-Assembly of Dendronized Perylene Bisimides. J.
Am. Chem. Soc. 2011, 133, 18479–18494.
(84) Percec, V.; Sun, H.-J.; Leowanawat, P.; Peterca, M.; Graf, R.;
Spiess, H. W.; Zeng, X.; Ungar, G.; Heiney, P. A. Transformation from
Kinetically into Thermodynamically Controlled Self-Organization
of Complex Helical Columns with 3D Periodicity Assembled from
Dendronized Perylene Bisimides. J. Am. Chem. Soc. 2013, 135,
4129–4148.
(85) Janiak, C. A Critical Account on π–π Stacking in Metal
Complexes with Aromatic Nitrogen-Containing Ligands. J. Chem.
Soc. Dalt. Trans. 2000, 3885–3896.
(86) Sygula, A.; Fronczek, F. R.; Sygula, R.; Rabideau, P. W.;
Olmstead, M. M. A Double Concave Hydrocarbon Buckycatcher. J.
Am. Chem. Soc. 2007, 129 (13), 3842–3843.
(87) Byung, H. H.; Dae, H. S.; Sung, Y. C. Graphite Catalyzed
Reduction of Aromatic and Aliphatic Nitro Compounds with
Hydrazine Hydrate. Tetrahedron Lett. 1985, 26 (50), 6233–6234.
(88) Sadrai, M.; Hadel, L.; Sauers, R. R.; Husain, S.; Krogh-
Jespersen, K.; Westbrook, J. D.; Bird, G. R. Lasing Action in a Family
of Peryiene Derivatives: Singlet Absorption and Emission Spectra,
Triplet Absorption and Oxygen Quenching Constants, and
Molecular Mechanlcs and Semiempirical Molecular Orbital
Calculations. J. Phys. Chem. 1992, 96 (20), 7988–7996.
(89) Ofir, Y.; Zelichenok, A.; Yitzchaik, S. 1,4;5,8-Naphthalene-
Tetracarboxylic Diimide Derivatives As Model Compounds for
Molecular Layer Epitaxy. J. Mater. Chem. 2006, 16, 2142.
(90) Chen, Z.; Debije, M. G.; Debaerdemaeker, T.; Osswald, P.;
Würthner, F. Tetrachloro-Substituted Perylene Bisimide Dyes as
Promising N-Type Organic Semiconductors: Studies on Structural,
(66) Wu, Y.-C.; Leowanawat, P.; Sun, H.-J.; Partridge, B. E.;
Peterca, M.; Graf, R.; Spiess, H. W.; Zeng, X.; Ungar, G.; Hsu, C.-S.;
Heiney, P. A.; Percec, V. Complex Columnar Hexagonal
Polymorphism in Supramolecular Assemblies of a Semifluorinated
Electron-Accepting Naphthalene Bisimide. J. Am. Chem. Soc. 2015,
137, 807–819.
(67) Partridge, B. E.; Leowanawat, P.; Aqad, E.; Imam, M. R.;
Sun, H.-J.; Peterca, M.; Heiney, P. A.; Graf, R.; Spiess, H. W.; Zeng, X.;
Ungar, G.; Percec, V. Increasing 3D Supramolecular Order by
Decreasing Molecular Order. A Comparative Study of Helical
Assemblies of Dendronized Nonchlorinated and Tetrachlorinated
Perylene Bisimides. J. Am. Chem. Soc. 2015, 137, 5210–5224.
(68) Chen, Z.; Baumeister, U.; Tschierske, C.; Würthner, F.
Effect of Core Twisting on Self-Assembly and Optical Properties of
Perylene Bisimide Dyes in Solution and Columnar Liquid
Crystalline Phases. Chem. – A Eur. J. 2007, 13, 450–465.
(69) Schmidt, R.; Ling, M. M.; Oh, J. H.; Winkler, M.; Könemann,
M.; Bao, Z.; Würthner, F. Core-Fluorinated Perylene Bisimide Dyes:
Air Stable N-Channel Organic Semiconductors for Thin Film
Transistors with Exceptionally High On-to-Off Current Ratios. Adv.
Mater. 2007, 19, 3692–3695.
(70) Percec, V.; Schlueter, D.; Kwon, Y. K.; Blackwell, J.;
Moeller, M.; Slangen, P. J. Dramatic Stabilization of a Hexagonal
Columnar Mesophase Generated from Supramolecular and
Macromolecular Columns by the Semifluorination of the Alkyl
Groups of Their Tapered Building Blocks. Macromolecules 1995, 28
(26), 8807–8818.
(71) Johansson, G.; Percec, V.; Ungar, G.; Smith, K.
Fluorophobic Effect Generates a Systematic Approach to the
Synthesis of the Simplest Class of Rodlike Liquid Crystals
Containing a Single Benzene Unit. Chem. Mater. 1997, 9, 164–175.
(72) Percec, V.; Imam, M. R.; Bera, T. K.; Balagurusamy, V. S. K.;
Peterca, M.; Heiney, P. A. Self-Assembly of Semifluorinated Janus-
Dendritic Benzamides into Bilayered Pyramidal Columns. Angew.
Chem. Int. Ed. 2005, 44 (30), 4739–4745.
(73) Wilson, C. J.; Wilson, D. A.; Feiring, A. E.; Percec, V.
Disassembly via an Environmentally Friendly and Efficient
Fluorous Phase Constructed with Dendritic Architectures. J. Polym.
Sci. Part A Polym. Chem. 2010, 48 (11), 2498–2508.
(74) Xiao, Q.; Rubien, J. D.; Wang, Z.; Reed, E. H.; Hammer, D.
A.; Sahoo, D.; Heiney, P. A.; Yadavalli, S. S.; Goulian, M.; Wilner, S. E.;
19
ACS Paragon Plus Environment

ACS Combinatorial Science
Page 20 of 21
Electrochemical and Charge Transport Properties. ChemPhysChem
2004, 5, 137–140.
Their Highly Conductive Complexes with Electron Donors. J. Chem.
Soc., Chem. Commun. 1986, No. 19, 1489–1491.
1
2
3
4
5
6
7
8
(91) Debije, M. G.; Chen, Z.; Piris, J.; Neder, R. B.; Watson, M.
M.; Müllen, K.; Würthner, F. Dramatic Increase in Charge Carrier
Lifetime in a Liquid Crystalline Perylene Bisimide Derivative upon
Bay Substitution with Chlorine. J. Mater. Chem. 2005, 15, 1270–
1276.
(92) Osswald, P.; Würthner, F. Effects of Bay Substituents on
the Racemization Barriers of Perylene Bisimides: Resolution of
Atropo-Enantiomers. J. Am. Chem. Soc. 2007, 129 (9), 14319–
14326.
(94) Hansen, M. R.; Graf, R.; Spiess, H. W. Solid-State NMR in
Macromolecular Systems: Insights on How Molecular Entities
Move. Acc. Chem. Res. 2013, 46 (9), 1996–2007.
(95) Hansen, M. R.; Graf, R.; Spiess, H. W. Interplay of
Structure and Dynamics in Functional Macromolecular and
Supramolecular Systems As Revealed by Magnetic Resonance
Spectroscopy. Chem. Rev. 2016, 116 (3), 1272–1308.
9
(93) Yamashita, Y.; Suzuki, T.; Saito, G.; Mukai, T. Novel
Quinone-Type Acceptors Fused with Sulphur Heterocycles and
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
20
ACS Paragon Plus Environment

Page 21 of 21
ACS Combinatorial Science
TOC Graphic
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
21
ACS Paragon Plus Environment