Synthesis, structural analysis, and visualization of a library of dendronized polyphenylacetylenes

Article abstract of DOI:10.1002/chem.200600009

A library of eleven high cis-content cis-transoidal polyphenylacetylenes (PPAs) dendronized with self-as-sembling dendrons was prepared from a library of fifteen convergently synthesized macromonomers. Using [Rh(C≡ CPh)(nbd)(PPh₃)₂]

Full text of DOI:10.1002/chem.200600009

FULL PAPER
DOI: 10.1002/chem.200600009
Synthesis, Structural Analysis, and Visualization ofa Library ofDendronized
Polyphenylacetylenes
Virgil Percec,*[a] Jonathan G. Rudick,[a] Mihai Peterca,[b] Sasha R. Staley,[a]
Martin Wagner,[a] Makoto Obata,[a] Catherine M. Mitchell,[a] Wook-Dong Cho,[a]
Venkatachalapathy S. K. Balagurusamy,[a, b] James N. Lowe,[a] Martin Glodde,[a]
Oliver Weichold,[a] Kyung J. Chung,[a] Nicholas Ghionni,[a] Sergei N. Magonov,[c] and
Paul A. Heiney[b]
Abstract: A library of eleven high cis-
content cis-transoidal polyphenylacety-
lenes (PPAs) dendronized with self-as-
sembling dendrons was prepared from
a library of fifteen convergently synthe-
ꢀ
serves as a helical scaffold for the self-
assembling dendrons. The dendron pri-
mary structure dictates the diameter of
the cylindrical PPAs in bulk,both in
the self-organized hexagonal columnar
(Fh) lattice determined by X-ray dif-
fraction (XRD) and in monolayers on
highly ordered pyrolytic graphite
(HOPG) and mica visualized by atomic
force microscopy (AFM). Thermal and
bulk phase characteristics of the cylin-
drical PPAs reinforces the generality
that flexible polymer backbones adopt
a helical conformation within the cylin-
drical macromolecules generated by
polymers jacketed with self-assembling
dendrons.
sized macromonomers. Using [Rh(C
G
CPh)
A
E
nadiene) in the presence of 10 equiv of
N,N-dimethylaminopyridine,predictive
control over molecular weight and
narrow molecular weight distribution
are obtained. The PPA backbone
Keywords:
helical structures
·
polymers · retrostructural analysis ·
self-organization · visualization
Introduction
thetic strategies.[3b,4–8] The last provides the highest degree of
structural perfection,particularly when combined with living
polymerization techniques.[4a,5d,e,7b–d,8] The synthetic demands
of the macromonomer strategy limit its utility. Consequently,
supramolecular strategies have emerged.[9,10] Using electron
donor–acceptor interactions,dendrons can bind to a linear
polymer backbone.[9] Alternately,non-covalent association
of apex functionalities in self-assembling dendrons generates
dendronized supramolecular polymers.[10] The supramolecu-
lar strategies offer novel functionality,such as self-healing,
ultra-high density arrays of helical wires,or arrays of helical
porous protein mimics.[9,10]
Dendronized polymers present an unparalleled level of ar-
chitectural complexity in synthetic macromolecules by deco-
rating each repeat unit of a linear polymer chain with a den-
dron.[1] Covalent connection of the dendron and backbone
relies upon divergent,[2] attach-to,[3] or macromonomer syn-
[a] Prof. V. Percec,Dr. J. G. Rudick,S. R. Staley,Dr. M. Wagner,
Dr. M. Obata,Dr. C. M. Mitchell,Dr. W.-D. Cho,
Dr. V. S. K. Balagurusamy,Dr. J. N. Lowe,Dr. M. Glodde,
Dr. O. Weichold,K. J. Chung,N. Ghionni
Roy & Diana Vagelos Laboratories
While dendronized polymers exhibit a well-defined cylin-
drical shape in solution,[6c,11] it is difficult to utilize that
structure as a building block for bottom-up self-assembly.
We have demonstrated that polymers jacketed with self-as-
sembling dendrons generate bulk order whose periodicity is
dictated by the diameter of individual dendronized poly-
mers.[5d,6,7d] The ability of these dendronized polymers to
generate periodic order (i.e.,self-organize) provides details
about the internal order of dendronized polymers. Such in-
ternal order can be further harnessed to improve functional-
Department of Chemistry,University of Pennsylvania
Philadelphia,PA 19104-6323 (USA)
Fax : (+1)215-573-7888
E-mail: percec@sas.upenn.edu
[b] M. Peterca,Dr. V. S. K. Balagurusamy,Prof. P. A. Heiney
Department of Physics and Astronomy
University of Pennsylvania
Philadelphia,PA 19104-6396 (USA)
[c] Dr. S. N. Magonov
Digital Instruments,Veeco Metrology Group
Santa Barbara,CA 93110 (USA)
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5731

ity. For example,X-ray diffraction (XRD) from oriented
fiber samples and solid-state NMR spectroscopy demon-
strated the helical internal order of electroactive dendron-
ized polymers.[9a] Control over the helical handedness may
enhance hole or electron mobility.
Moore and Stupp,[17] the dendritic carboxylic acids and 4-
ethynylbenzyl alcohol were coupled using dicyclohexylcar-
bodiimide (DCC) and N,N-dimethylaminopyridinium tosy-
late (DPTS) in CH2Cl2. Typically,catalytic amounts of
DPTS are needed to suppress formation of the undesired N-
acyl urea byproduct. Nonetheless,trace amounts of the side
product were observed during chromatography of reaction
mixtures involving dendritic carboxylic acids in excess of
1 kDa. We found that substoichiometric or stoichiometric
quantities of DPTS were necessary to eliminate this compli-
cation. A similar procedure has been employed for benzoyl
ester dendron syntheses.[18]
Polymers jacketed with covalently attached dendrons pro-
vide a model for understanding how to dictate the internal
order of cylindrical dendronized polymers. Models con-
structed from XRD studies and AFM visualization for poly-
styrenes (PSs),[6] poly(methacrylate)s,[6,7a] poly(7-oxanorbor-
nene)s[7b,c] and poly(maleimide)s[7b] dendronized with self-as-
sembling dendrons suggest that the polymer backbone
adopts short range helical order within the cylindrical struc-
ture. Polyarylacetylenes adopt a helical conformation[12,13]
whose sense can be biased by incorporating chiral,non-race-
mic side chains.[14] Circular dichroism (CD) spectroscopy
provides direct information about the helical bias of the
conjugated polyarylacetylene backbone. Aoki and co-work-
ers prepared dendronized PPAs that self-organized into a
hexagonal lattice,but did not attempt to control helix
sense.[5a,b] Meijer and co-workers prepared a dendronized
PPA with a predominantly single-handed helix sense,but ex-
hibits a smectic liquid crystalline phase.[5c] Sergeant-and-sol-
diers experiments using poly(N-substituted-2-ethynylcarba-
zole)s and poly(N-substituted-3-ethynylcarbazole)s demon-
strated that the helical sense of the latter is more easily bia-
sed.[5d] The NC phase displayed by these polymers precluded
bulk observation of intracolumnar helical order by XRD.[5d]
The design and synthesis of dendronized PPAs that self-
organize into a Fh phase and whose helix sense can be pre-
dictably controlled has been accomplished by surveying a li-
brary of such structures. We recently reported[5e] a particular
dendron substitution pattern whose size matches the helical
pitch of the backbone. A detailed model for the bulk struc-
ture was arrived at based on XRD studies of oriented fiber
samples and molecular modeling studies. CD Spectroscopy
of a dendronized PPA incorporating chiral,non-racemic
tails in a solvent selective for the periphery confirmed selec-
tion of a particular helix sense. Herein we report the synthe-
sis and structural analysis of the complete library of
dendronized PPAs. Visualization of helical cylindrical PPAs
confirmed that ordering on highly ordered pyrolytic graphite
(HOPG) and mica surfaces is dictated by individual
dendronized PPAs. Thermal and structural analysis of this li-
brary underscores the generality of the helical model arrived
at for the aforementioned dendronized PPA to other flexi-
ble polymers jacketed with self-assembling dendrons.
The dendritic macromonomers were polymerized using
ꢀ
[Rh
A
G
N
presence of 10 equiv of N,N-dimethylaminopyridine
(DMAP) in THF.[19] The catalyst was chosen because it in-
duces polymerization of arylacetylenes with living character:
predictive control over molecular weight (Mn),narrow mo-
lecular weight distribution (Mw/Mn),and presence of active
chain ends.[19] RhI-based catalysts effect the stereoselective
polymerization of arylacetylenes containing a variety of
functionalities.[19,20] Table 1 reports reaction conditions and
structural characteristics of dendronized PPA obtained by
polymerization of dendritic macromonomers. It is worth
noting that poly
A
[Rh(nbd)Cl]2/NEt3 in THF,while polymerizations of benzyl
AHCTREUNG
ether-containing macromonomers proceeded to modest con-
version providing intractable materials.
Gel permeation chromatography (GPC) typically under-
estimates Mn of dendronized polymers.[3b,6,8,11] Furthermore,
light scattering on PSs and polymethacrylates jacketed with
self-assembling dendrons confirmed this underestimation
and showed that anomalous elution behavior occurs for ex-
tremely high molecular weight fractions.[6c] Comparison of
the molecular weights reported therein to the results in
Table 1 indicates that such behavior should not complicate
the present results. In addition to Mn and Mw/Mn,Table 1 re-
1
ports cis-content[12] determined by H NMR spectroscopy of
the polymers in CDCl3. Figure 1 illustrates a representative
spectrum and outlines the determination of cis-content ac-
cording to the method outlined for PPA.[12] The estimate
overlooks the presence of cyclohexadiene repeat units that
result from electrocyclization of cis-1,3,5-hexatriene sequen-
ces in the polyene backbone (Scheme 1).[21–23] The vinylic
proton resonances from the cyclohexadiene ring overlap the
cis-polyene resonance. Due to the dendron structure,the cy-
clohexadiene content cannot be reliably determined,so this
approximation is the best estimate of the backbone stereo-
structure.
Results and Discussion
Three different reaction protocols were employed. In
ꢀ
most cases,solutions of monomer and catalyst (i.e.,[Rh (C
G
Synthesis and structural analysis in solution: Following the
convergent synthetic strategy outlined by our laboratory,we
have prepared a library of self-assembling dendritic carbox-
ylic acids.[6c,15] The polymerizable apex group,4-ethynylben-
zyl alcohol,was synthesized following a combination of liter-
ature reports.[16] Utilizing the esterification protocol of
CPh)
A
E
and the monomer solution was added to the catalyst. Alter-
nately,in some cases the catalyst solution was added to the
monomer solution. Because the heat of reaction can alter
the stereostructure of PPAs,[12] the monomer and catalyst
solutions were maintained between 20 and 238C. Addition
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Dendronized Polyphenylacetylenes
FULL PAPER
ꢀ
Table 1. Polymerization of dendritic 4-ethynylbenzyl esters with [Rh
THF.
A
G
G
cis-content. The latter likely re-
sults from cyclization or isomer-
ization of the polyene backbone
during polymerization. Compar-
ison to polymerizations of
(3,4,5-3,4)12G2-4EBn
(entry 20) and (3,4,5-3,5)12G2-
4EBn (entry 21),which are ki-
netically sluggish reactions,in-
dicate that long reaction times
are not inherently deleterious.
In the absence of monomer,the
RhI-based propagating species
or byproduct formed during
generation of the active cata-
lyst[19b,20] may promote cycliza-
tion or isomerization. We have
recently shown that cyclization
in cis-transoidal PPA is acceler-
ated in acidic media.[22]
[a]
[c]
Monomer
(3,4)12G1-4EBn
DPth
[M]0 [m] t [h] Yield [%][b] Mn ”10ꢁ3[c] Mw/Mn
cis Content [%][d]
A
57[e] 0.072
6
4
4
7.5
120
7
8
12
7
71
64
71
77
62
57
74
76
92
62
68
79
68
72
50
77
67
67
65
75
83
56
51.8
59.6
61.7
192.6
–
87
97
86
90
65[e] 0.072
66[e] 0.15
63[f] 0.144
24[e] 0.060
26[h] 0.034
50[h] 0.046
56[h] 0.048
84[h] 0.063
44[e] 0.052
49[e] 0.050
50[h] 0.048
113[h] 0.060
47[e] 0.051
27[h] 0.032
44[e] 0.049
51[h] 0.050
51[e] 0.049
103[h] 0.064
47[e] 0.050
23[h] 0.292
54[f] 0.106
[g]
[g]
A
–
–
G
33.9
50.9
65.8
82.4
65.3
61.0
71.0
202.8
64.4
34.2
68.1
72.2
77.3
139.4
54.2
38.5
109.3
79
89
72
88
87
82
80
86
85
73
68
88
54
95
80
76
100
T
2.5
6
ACHTREUNG
R
2.4
14
5.5
2.5
10
2.5
32
5
ACHTREUNG
ACHTREUNG
(3,4,5-3,4)12G2-4EBn
(3,4,5-3,5)12G2-4EBn
(4-3,4-3,5)12G2-4EBn
21.5
21
8
Kinetic experiments for the
polymerization
of
(3,4-
[a] Theoretical degree of polymerization=[4EBn]0/[Rh]0. [b] Yields are corrected for conversion. [c] Deter-
mined by GPC (THF,1 mLmin ꢁ1) calibrated with polystyrene standards. [d] Determined as prescribed in ref.
[12]. [e] A solution of monomer was added to a solution of catalyst and the reaction vessel immersed in a water
bath at 20–238C. [f] A solution of catalyst was added to a solution of monomer and the reaction vessel im-
3,5)12G2-4EBn were undertak-
en to elucidate the living char-
acter noted above. Figure 3 il-
lustrates the results. The reac-
tion proceeds to high conver-
sion with time,but the semi-
logarithmic plot shows devia-
tion from linearity at high con-
mersed in a water bath at 22–238C. [g] Insoluble in THF,benzene,CHCl 3,CH Cl2,and a,a,a-trifluorotoluene.
2
[h] Solvent was added to a solid mixture of monomer and catalyst and the reaction stirred without control
over temperature.
of catalyst to the monomer introduced large variations in
the molecular weight of the polymer obtained. For example,
version (Figure 3a). The reaction loses first-order character,
which may be indicative of side reactions. The shape of the
plot of Mn,GPC versus the conversion corrected theoretical
molecular weight (Mn,th,Figure 3b) is complicated by com-
ꢀ
entries 3 and
4 in Table 1 for the polymerization of
ACHTREUNG
from polymerization of (4-3,4-3,5)12G2-4EBn (Table 1
entry 22). These discrepancies are,most likely,due to loss of
some catalyst solution volume during transfer. Due to the
small amount of solvent employed in these polymerizations,
dissolution of a solid mixture of monomer and catalyst was
found to be convenient,even without controlling for reac-
tion temperature. Comparison of results in Table 1 show
that this method provides results comparable to the method
of adding the monomer solution to the catalyst.
peting behavior. The [Rh
(C CPh)
U
E
system is noted for its low initiator efficiency,[19b] which
leads to an upward deviation in the plot. Coincident with
this behavior is the underestimation of Mn by GPC noted
above. The plot of Mw/Mn versus the conversion corrected
theoretical molecular weight (Figure 3b) clearly shows be-
havior uncharacteristic for a living polymerization. The mo-
lecular weight distribution increases with conversion,which
is indicative of termination reactions. Close inspection of re-
sults for the polymerization of phenylacetylene using [Rh-
ꢀ
Variation of [M]0/[Rh]0 allowed for predictive control of
molecular weight. Figure 2 shows a plot of Mn determined
N
G
U
by GPC versus [M]0/[Rh]0 for polymerizations of
A
4EBn, (3,4,5)12G1-4EBn,and (3,4-3,5)12G2-4EBn. The
A
G
Termination of propagating species during arylacetylene
polymerization appears to be most significant at high con-
version. The side reactions become kinetically competent
when the velocity of the propagation reaction becomes
small due to low monomer concentration. As noted above,
the steric demand and molecular weight of the dendritic
macromonomers results in sluggish polymerization reactions.
A decrease in rate constant of propagation with increasing
dendron size is noted for polymerization of bisdendritic 7-
oxanorbornene macromonomers appended with self-assem-
bling dendrons.[7b,c] For large dendrons,the termination reac-
linear dependence of molecular weight on [M]0/[Rh]0 sug-
gests that the polymerizations possess living character. All
of the polymerizations reported in Table 1 proceed to 80%
conversion or higher. The low concentrations employed
were chosen to ensure that the monomer is dissolved and
that the reaction mixture remains fluid at high conversion.
Unfortunately,the low concentrations lead to long reaction
times for some monomers. Entries 16 and 18 of Table 1 for
the polymerization of
A
reaction times lead to broadened polydispersity and lower
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5733

V. Percec et al.
of the dendron,the absorption maximum is red-shifted by
15–20 nm compared with THF. This suggests that solvopho-
bic collapse of the benzyl ether region of the dendrons in
hexanes results in stretching of the polymer backbone,
which is manifested as the red shift of the UV/Vis spectra.
Structural analysis in bulk: Thermal phase behavior of the
dendronized PPAs was determined by differential scanning
calorimetry (DSC) and thermal optical polarized microscopy
(TOPM). None of the textures observed by TOPM were dis-
tinctive. Poly[(3,4)12G1-4EBn] showed large homeotropi-
G
cally aligned domains. Also notable,this dendronized PPA
is the only sample where isotropization occurs before de-
composition. For the range of Mn reported in Table 1,the
isotropization temperature during second heating only
ranged between 76 and 788C. All other polymers decom-
pose before isotropization. Nonetheless,reversible heating
and cooling cycles can be obtained if the maximum temper-
ature is kept 208C below the observed decomposition tem-
perature. Table 2 summarizes the phase behavior deter-
mined by DSC. Representative second heating and cooling
DSC cycles are shown in Figure 5.
The lattice symmetry of the self-organized phases was as-
signed based on XRD experiments. Two types of behavior
were generally observed. Figure 6 illustrates representative
diffraction patterns and plots of integrated diffraction inten-
sity. Patterns characterized primarily by a broad,intense re-
flection indexed as d10 and a higher-order broad,diffuse re-
flection is indexed as overlapping d11 and d20 reflections of a
hexagonal lattice (Figure 6a,b). In the case of poly-
A
decomposition,no improvement of ordering is observed on
cooling and subsequent heating cycles. Similar behavior is
observed in poly
N
N
3,4)12G2-4EBn]. Except for poly[(3,4,5-3,4)12G2-4EBn],
the other dendronized PPAs exhibit diffraction patterns sim-
ilar to that illustrated in Figure 6c,d. Three reflections that
can be indexed as d10, d11,and d20 of a hexagonal lattice are
observed.
Figure 1. 1H NMR spectra of
3,4,5)12G1-4EBn] (bottom).
N
G
Some higher order reflections were observed in oriented
tion(s) can be significant at modest conversions. We have
observed that some macromonomers cannot be effectively
fiber samples of poly
3,4,5)12G1-4EBn],and poly
shows representative wide angle XRD patterns and plots
from poly[(3,4,5)12G1-4EBn] at 23 and 738C. We have re-
cently discussed the structural significance of the observed
Fiho-to-Fh transition in poly[(3,4-3,5)12G2-4EBn].[5e] A ther-
moreversible process of stretching along the column axis ex-
plains the structural changes observed by XRD: discontinu-
ous column diameter contraction (expansion) and loss (ap-
pearance) of helical features on heating (on cooling). To ac-
commodate these changes the polymer backbone undergoes
conformational isomerization for cis-cisoidal to cis-transoi-
dal upon heating in bulk. This inhibits the cyclization event
typically associated with thermally-induced transformations
of PPAs.[12,21–23]
A
[(4-
ACHTREUNG
ꢀ
polymerized using the [Rh
A
G
N
catalyst. Despite this limitation,we have prepared the larg-
est library of dendron structures appended to a single poly-
mer backbone. Scheme 2 illustrates the complete library of
dendronized PPAs.
ACHTREUNG
AHCTREUNG
As a result of conjugation along the polyene backbone,
the dendronized polymers are obtained as yellow powders
after freeze drying from benzene. In a given solvent (e.g.,
THF or hexanes),comparison of UV/Vis spectra of several
dendronized PPAs shows no observable difference
(Figure 4). Therefore,the influence of dendron structure on
the backbone conformation seems to be negligible in solu-
tion. By contrast,the choice of solvent does influence the
long wavelength absorption associated with the polymer
backbone. In hexanes,a solvent selective for the periphery
Table 3 enumerates the lattice symmetry,observed d spac-
ings,lattice parameter ( a),experimental density measured
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Dendronized Polyphenylacetylenes
FULL PAPER
Scheme 1. 6p Electrocyclization of cis-1,3,5-hexatriene sequences in PPA and chain cleavage due to rearomatization of the resulting 1,3-cyclohexadiene
repeat units.
Figure 2. Plot of molecular weight determined by GPC (Mn,GPC) relative
to polystyrene standards as a function of theoretical degree of polymeri-
~
zation (DPth =[M]0/[Rh]0) for poly
A
(
), poly-
&
*
G
N
at 208C (120),and number of dendrons per column stratum.
Drawing on these assignments we identify dendrons with
3,4-branching elements adjacent to the polymer backbone as
the source of poor hexagonal ordering. Additionally,
poly[(3,4,5-3,4)12G2-4EBn] is self-organized in a simple rec-
tangular columnar (Fr-s) lattice. Unlike with flexible poly-
mer backbones,the dendron is limited to how it can contort
the PPA backbone. Semifluorination of the peripheral alkyl
tails provides a strong driving force for microphase segrega-
tion within the cylindrical macromolecule. The semifluori-
nated alkyl tails fill a larger and more extended volume of
space than their hydrocarbon analogues. For example,for
ꢀ
Figure 3. Polymerization of
A
G
R
A
A
=
^
( )
[M]0 =0.052m. a) Plot of conversion
^
(ln([M]0/[M]), ) versus time for the same reaction. b) Plot of experimen-
tal Mn,GPC (GPC vs PS standards) ( ) and Mw/Mn (&) versus Mth.
&
4EBn]), ~50 Š (e.g., poly[(4-3,4,5)12G1-4EBn]),and ~60 Š
A
(e.g., poly[(4-3,4-3,5)12G2-4EBn]).
poly
A
a=39.5 Š
while
for
poly-
Unique to polymers dendronized with self-assembling
dendrons,bulk characterization provides direct measure-
ment of the diameter of a single macromolecule in the self-
organized lattice. We have previously shown that for poly-
mers jacketed with self-assembling dendrons,the size of the
cylindrical macromolecule defines the fundamental element
for periodic order at interfaces.[5d,6,7d] Cylindrical PPAs can
serve as structural building blocks for bottom-up self-assem-
ACHTREUNG
compensated by 3,5- and 3,4,5-branching adjacent to the
polymer backbone. The diameter of the cylindrical object is
largely dictated by the length of the peripheral alkyl tail and
the number of benzyl ether layers,regardless of substitution
pattern. By this latter strategy we have prepared cylindrical
PPAs with diameters of ~40 Š (e.g., poly[(3,4,5)12G1-
A
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V. Percec et al.
Scheme 2. Library of dendronized polyphenylacetylenes.
bly. The helical conformation of the polymer backbone is of
further interest to understand chirality at interfaces. Visuali-
zation of cylindrical PPAs using AFM confirms that periodic
structures are formed on HOPG (Figure 8). Averaging over
several cylindrical elements in the images we can estimate
the length-scale of the periodic order. Table 4 reports the
measured diameter by AFM visualization. We note good
agreement between the results in Table 4 with a from
Table 3,which underscores that individual cylindrical macro-
molecules define the observed self-organization on HOPG
and mica.
shape. This is reflected in the modest overestimation of mac-
romolecular diameter determined by AFM on HOPG com-
pared to XRD measurements in bulk (Figure 8c). In con-
trast,the cylindrical diameter measured by AFM on mica is
remarkably close to that determined by XRD (Figure 8d).
Effect of stiffening the polymer backbone: Both PPA and
PS offer relatively flexible scaffolds for dendronized poly-
mers. Unmitigated by dendrons,PS adopts a random coil
conformation,while PPA adopts a helical conformation due
to fewer degrees of conformational freedom. The conse-
quences of this restricted conformational flexibility are ap-
parent in the observation of poorly ordered Fh lattices in
specific samples. Since the dendron cannot force the back-
bone into a conformation that matches its preferred pack-
ing,nor can some dendrons appropriately fill space,the cy-
lindrical macromolecules cannot pack well into a two-di-
mensional lattice.
Figure 8 illustrates monolayers of poly[(3,4-3,5)12G2-
A
4EBn] on HOPG and mica. On both surfaces,domains of
rod-like objects oriented parallel to each other can be iden-
tified. On HOPG,boundaries form between domains orient-
ed ~1208 to each other. This orientation reflects the under-
lying six-fold symmetry of the graphite surface and is driven
by epitaxial adsorption of the peripheral alkyl chains.[6f]
Mica is hydrophilic,so there is no preferential adsorption of
the cylindrical PPA. The result of epitaxial adsorption is
that the cylindrical PPA is deformed into a more oblate
Dendronized PPAs decompose at lower temperatures
than the corresponding dendronized PSs.[6c] This can have
origins in the mobility of the dendronized polymer due to
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Dendronized Polyphenylacetylenes
FULL PAPER
Figure 5. Representative second heating (top) and second cooling
(bottom) DSC traces for poly
N
N
4EBn],and poly[(3,4-3,5)12G2-4EBn].
AHCTREUNG
molecular weight or macromolecular flexibility. With regard
to the dendron architectures herein,PSs dendronized with
self-assembling dendrons typically undergo isotropization at
temperatures similar to the decomposition temperatures ob-
served with dendronized PPAs. Dendronized polymers with
Mn in excess of 100000 decompose (~2908C) before isotrop-
ization. Given the relatively low Mn of the dendronized
PPAs,the low decomposition temperatures need considera-
tion.
Figure 4. UV/Vis Spectra of poly
4EBn] (2), poly[(4-3,4,5)AmylG1-4EBn] (3), poly
(4), poly[(3,4-3,4)12G2-4EBn] (5), poly
C
[(3,4,5)12G1-
U
ACHTREUNG
G
ACHTREUNG
Intramolecular 6p electrocyclization of cis-1,3,5-hexa-
triene sequences in the polyene backbone to form cyclohex-
adiene repeat units accounts for
the thermal transformations of
Table 2. Thermal characterization of cylindrical PPA macromolecules.
PPA in bulk and solution.[12,21–23]
Polymer
Mn ”10ꢁ3[a]
Thermal transitions [8C] and
Rearomatization of cyclohexa-
diene repeat units results in ex-
trusion of 1,3,5-triphenylben-
zene and concomitant chain
cleavage.[12,21–23] In bulk,these
processes are detectable by
DSC as endothermic events.[12]
The decomposition of dendron-
ized PPAs in bulk is exother-
mic,and not likely caused by
cyclization and rearomatization.
We further note,that the ex-
truded 1,3,5-triarylbenzenes are
expected to be discotic liquid
crystalline dendrimers. Finally,
we have observed that in bulk,
corresponding enthalpy changes [kcalmolꢁ1
]
[b]
Heating
Cooling
[c]
poly
poly
poly
poly
poly
poly
poly
poly
U
61.7
–
50.9
65.3
k ꢁ4 (2.19) Fh 78 (0.41) i
i 73 (0.44) Fh 6 (1.53) k
Fh 125 dec[d]
Fiho [e] 110 dec
Fh 183 dec
Fh 90 dec
71.0
64.4
68.1
54.2
38.5
109.3
Fiho 106 (0.29) Fh 115 dec
Fh 130 dec
Fh,g 0 (3.63) Fiho 88 (1.11) Fh 140 dec
[f]
poly[(3,4,5-3,4)12G2-4EBn]
poly[(3,4,5-3,5)12G2-4EBn]
poly[(4-3,4-3,5)12G2-4EBn]
Fr-s[g] 130 dec
Fh 160 dec
Fh 120 dec
[a] Determined by GPC (THF,1 mLmin ꢁ1) calibrated with polystyrene standards. [b] Data from second heat-
ing and cooling DSC scans at 108Cminꢁ1. [c] Fh, p6mm hexagonal columnar lattice. [d] dec,onset of decompo-
sition as indicated by the lack of reversible heating/cooling cycles above this temperature. [e] Fiho, p6mm hex-
agonal columnar lattice with intracolumnar order. [f] Fh,g ,glassy state of the p6mm hexagonal columnar lat-
tice. [g] Fr-s, p2mm simple rectangular columnar lattice.
Chem. Eur. J. 2006, 12,5731 – 5746
ꢀ 2006 Wiley-VCH Verlag GmbH & Co. KGaA,Weinheim
www.chemeurj.org
5737

V. Percec et al.
poly[(3,4-3,5)12G2-4EBn] is thermally stable due to cisoid-
A
to-transoid conformational isomerization of the polyene
backbone during the Fh-to-Fiho phase transition.[5e]
Short-range helical order of the backbone has been pro-
posed for flexible polymers dendronized with self-assem-
bling dendrons.[6,7] This model is arrived at based on model-
ing of a backbone confined to the core of the cylindrical
macromolecule,XRD experiments,and from conformation-
al analysis of individual macromolecules visualized using
AFM. Using XRD and CD spectroscopy,we have substanti-
ated such a model for a series of poly
with various peripheral alkyl chains (m).[5e] The structural
characteristics of poly[(4-3,4,5)12G1-4EBn] and poly[(3,4-
3,5)12G2-4EBn] (Table 3) in the Fiho phase and their PS
counterparts poly
[(4-3,4,5)12G1-4VBn] (a=49.3 Š,[5c] m=
6.8 assuming t=4.75 Š) and poly[(3,4-3,5)12G2-4VBn] (a=
A
A
ACHTREUNG
AHCTREUNG
AHCTREUNG
48.8 Š,[5c] m=4.9 assuming t=4.75 Š) are strikingly similar.
Therefore,little difference is expected in the internal helical
order of both structures. Given the predisposition of the
PPA backbone to adopt a helical conformation and the
quantitative correspondence between each of the dendron-
ized PPAs and their PS analogue,it is consistent that poly-
mers confined to the core of the cylinder exhibit short-range
helical order that can be directed by chirality in the den-
dron.
Figure 6. Representative XRD patterns (a and c) and plots of XRD in-
tensity (b and d) from the hexagonal columnar (Fh) lattices exhibited by
(a and b) poly
N
N
4EBn].
Conclusion
High cis-content cylindrical cis-transoidal PPAs are prepared
from self-assembling dendrons functionalized with polymer-
ꢀ
izable 4-ethynylbenzyl esters at their apex using [Rh
CPh)(nbd)
C
G
G
system allows for predictive control over Mn and narrow
Mw/Mn. Kinetic experiments reveal that the polymerization
is limited by termination reactions,which become kinetically
significant at low [M] or low kp. The steric size of the den-
dron results in reduced kp and,for some dendritic macromo-
nomers,the catalyst is not competent. Nonetheless a library
of dendronized PPAs comprised of eleven different dendron
branching structures has been prepared.
Structural analysis in bulk and solution lead to a general
picture of how the polymer backbone is accommodated in a
helical arrangement in the core of the cylindrical object.
Self-assembling dendrons are capable of forcing the polymer
backbone into a conformation that matches the preferred
packing of the dendrons. In solution,UV/Vis spectroscopy
indicated that the dendron structure does not significantly
alter the degree of conjugation along the polyene backbone.
From XRD in the self-organized phase,we find that the less
flexible PPA backbone impedes the ideal packing of the
dendrons. Design principles related to how the dendron fills
space are elucidated for distinguishing dendronized PPAs
that self-organize into well-ordered Fh lattices. By correla-
tion between a library of dendronized PSs and the present
library of dendronized PPAs,we generalized the short-range
Figure 7. Wide angle X-ray diffraction patterns from poly[(3,4,5)12G1-
A
4EBn] collected at a) 23 and b) 738C,and c) the corresponding stack
meridional plots. Legend: i-short range helical feature; tꢁ54 ꢂ 98 den-
dron tilt angle; m1 and m2-meridional helical features; h1-long range heli-
cal feature; (10),(11) and (20)-( hk0) reflections of the columnar hexago-
nal phase.
5738
www.chemeurj.org
ꢀ 2006 Wiley-VCH Verlag GmbH & Co. KGaA,Weinheim
Chem. Eur. J. 2006, 12,5731 – 5746

Dendronized Polyphenylacetylenes
FULL PAPER
Table 3. Measured d spacings and structural analysis of the columnar lattices generated from cylindrical PPAs.
Experimental Section
[b]
Polymer
T
[8C]
Lattice
d Spacings [Š]
a (a,b)[a] 120
m[c]
[d]
[e]
[d]
[d]
[e]
d100
d100
d110
d010
d200
d120
d210
[Š] ]
A
Materials: N,N’-Dicyclohexylcarbodi-
imide (DCC,99%),and a,a,a-trifluor-
otoluene (99%) were used as received
from Acros. 4-(N,N-Dimethylamino)-
pyridine (DMAP,Acros,99%) was re-
crystallized from toluene before use.
Dichloromethane (CH2Cl2,Fisher,
A.C.S. reagent) was freshly distilled
from CaH2 (Sigma-Aldrich,coarse
granules, ~20 mm,95%) under argon.
Tetrahydrofuran (THF,Fisher,A.C.S.
reagent) was freshly distilled from
sodium/benzophenone under argon.
Benzene (Acros) dried by passing
through a column of activated alumina
under N2 pressure. Hexanes,acetone,
ethyl acetate (EtOAc,A.C.S. reagent),
[e]
[e]
poly
poly
poly
poly
C
25
25
25
25
85
p6mm 39.8
p6mm 45.0
p6mm 34.3
p6mm 46.8
p6mm 48.3
20.0
22.4
17.2
23.4
23.8
45.9
52.2
39.8 0.98
53.4
54.1
32.0
26.4
19.8
26.0
25.8
18.6
4.7
5.4
poly
4EBn]
poly
120 p6mm 31.8
p6mm 40.2
p6mm 40.7
p6mm 41.0
23.1
23.4
23.1
23.0
26.2
25.3
25.2
24.9
22.4
36.8
20.0
20.3
20.8
20.1
24.0
22.8
22.0
21.7
19.5
23.3
46.3 1.03
46.9
47.2
46.2
53.8
51.9
50.6 1.01
49.6
85
90
115 p6mm 40.0
p6mm 46.5
100 p6mm 45.5
p6mm 43.7
70
105 p6mm 38.9
70
poly
poly
5.25
p6mm 43.2
44.9
methanol (MeOH),NaOH,MgSO
,
4
poly[(3,4,5-3,4)12G2-
4EBn]
poly[(3,4,5-3,5)12G2-
4EBn]
p2mm 46.1
18.0 a=46.5[f]
b=36.1[f]
46.0
anhydrous Na2SO4,and NaHCO (all
3
A.C.S. Certified or A.C.S. Certified
PLUS) were used as received from
Fisher. 4-(N,N-Dimethylamino)pyridi-
nium tosylate (DPTS) was prepared
according to a literature procedure.[17]
ꢀ
25
p6mm 39.8
23.0
20.0
60
30
p6mm 39.3
p6mm 49.4
22.8
27.3
19.8
25.3
45.3
56.6
poly[(4-3,4-3,5)12G2-
4EBn]
[Rh
(C CPh)
N
N
75
p6mm 53.2
31.1
27.6
62.5
pared according to a literature pro-
cedure and used without recrystalli-
zation.[19] The synthesis of 4-ethynyl-
[a] Lattice parameter for the p6mm columnar hexagonal lattice a=2hd100i3ꢁ0.5,where hd100i=0.25(d100
+
0.5
0.5
3
d
+ 2d200 + 7 d ) and is equal to the diameter of a column (Dcol). [b] 120,Experimental density meas-
110 210
benzyl alcohol[16] and poly
[(3,4-
R
ured at 208C. [c] Number of dendrons in a column stratum=(30.5NAat120)(2m)ꢁ1,where Avogadroꢁs number
G
NA =6.0220455”1023,layer thickness t=4.75 Š,and M is the molecular weight of the monomer. [d] d Spacings
for the p6mm hexagonal columnar lattice. [e] d Spacings for the p2mm simple rectangular columnar lattice.
[f] Lattice parameters a=hd and b=kd the p2mm simple rectangular columnar lattice.
3,5)12G2-4EBn] have been described
previously.[5g] 3,4-Didodecyloxybenzoic
acid
((3,4)12G1-CO4H- ),3,
A
2
Table 4. Average column diameter measured from images visualized by
AFM.
Polymer
wAFM [Š]
HOPG
Mica
poly
poly
poly
C
58
70
66
86
–
–
48
–
poly[(4-3,4-3,5)12G2-4EBn]
di(5,5,6,6,7,7,8,8,9,9,10,10,11,11,12,12,12-heptadecafluorododecan-1-yloxy)-
benzoic acid (3,4)12F8G1-CO2H), 3,4,5-tridodecyloxybenzoic acid
(3,4,5)12G2-CO2H),34,-bis[(4 ’-dodecan-1-yloxy)benzyloxy]benzoic acid
(4-3,4)12G1-4EBn), 3,4,5-tris[4-((S)-3-methylbutan)-1-yloxy)benzyloxy]-
(4-3,4,5)AmylG1-CO2H), 3,4,5-tris[(4’-dodecan-1-yloxy)-
benzyloxy]benzoic acid ((4-3,4,5)12G1-CO2H),34,-bis(3 ’,4’-bis(dodecan-
1-yloxy)benzyloxy)benzoic acid (3,4-3,4)12G2-CO2H), 3,4,5-tris(3’,4’-
bis(dodecan-1-yloxy)benzyloxy)benzoic acid ((3,4-3,4,5)12G2-CO2H),
3,4-bis(3’,4’,5’-tris(dodecan-1-yloxy)benzyloxy)benzoic acid ((3,4,5-
3,4)12G2-CO2H),53-,bis(3 ’,4’,5’-tris(dodecan-1-yloxy)benzyloxy)benzoic
(
ACHTREUNG
(
(
ACHTREUNG
AHCTREUNG
benzoic acid
(
ACHTREUNG
AHCTREUNG
(
ACHTREUNG
acid ((3,4,5-3,5)12G2-CO2H), 3,4,5-tris(3’,4’,5’-tris(dodecan-1-yloxy)ben-
zyloxy)benzoic acid ((3,4,5-3,4,5)12G2-CO2H),35,-bis{3 ’,4’-bis[(4’’-dodec-
an-1-yloxy)benzyloxy]benzyloxy}benzoic acid ((4-3,4-3,5)12G1-CO2H),
3,5-bis{3’,5’-bis[3’’,4’’-bis(dodecan-1-yloxy)benzyloxy]benzyloxy}benzoic
acid ((3,4-3,5-3,5)12G3-CO2H),and 35,-bis(3 ’,5’-bis{3’’,4’’-bis[(4’’’-dodec-
Figure 8. AFM Visualization of poly[(3,4-3,5)12G2-4EBn] on a) HOPG
A
and b) mica. Illustration of cylindrical PPAs on c) HOPG and d) mica.
The oblate shape on HOPG is due to epitaxial adsorption of the alkyl
tails to the graphite underlayer.
an-1-yloxy)benzyloxy]benzyloxy}benzyloxy)benzoic
3,5)12G3-CO2H) were prepared a described previously.[6c,15,24]
Techniques: NMR Spectra (1H,500 MHz, 13C,125 MHz,and
acid
((4-3,4-3,5-
19F,
470 MHz) were recorded on Bruker DRX 500 and Bruker AMX 500
spectrometers in CDCl3 (with 5 v/v% tetramethylsilane (TMS) internal
standard) at 278C unless otherwise noted. Chemical shifts are reported
helical order model for flexible polymers confined to the
cylinder core.
Chem. Eur. J. 2006, 12,5731 – 5746
ꢀ 2006 Wiley-VCH Verlag GmbH & Co. KGaA,Weinheim
www.chemeurj.org
5739

V. Percec et al.
as d,ppm. Circular dichroism (CD) and corresponding UV/Vis spectra
were recorded on a Jacsco J-720 spectropolarimeter equipped with a
Thermo NesLab RTE-111 variable temperature circulating bath. Specific
optical rotations [a]D were determined using a Jasco P-1010 polarimeter.
UV/Vis Spectra were recorded using a Shimadzu UV-1601 spectropho-
tometer.
8.4, 4J
1H; aromatic C(2)H),7.50 (d,
C(3)H and C(5)H),7.39 (d, (H,H)=8.1 Hz,2H; 4EBn aromatic C(2) H
and C(6)H),7.31 (d, (H,H)=2.2 Hz,2H; aromatic C(2)H and C(6)H),
6.86 (d, (H,H)=8.1 Hz,2H; aromatic C(5) H),5.33 (s,2H; 4EBn
ArCH2O),4.04 (t, (H,H)=6.7 Hz,2H; ArOC H2),4.03 (t, (H,H)=
6.8 Hz,2H; ArOC H2),3.08 (s,1H; alkyne C H),1.83 (m,4H; Ar-
OCH2CH2),1.48 (m,4H; ArO (CH2)2CH2),1.36 (m,overlapped),1.27
(overlapping s,32H; ArO (CH2)3(CH2)8),0.89 (t, (H,H)=6.9 Hz,6H;
ArO
(CH2)11CH3); 13C NMR (125 MHz,CDCl 3,25 8C,TMS): d=166.54
(CO2CH2),153.87 (aromatic C(3)),149.00 (aromatic C(4)),137.48 (4EBn
aromatic C(1)),132.66 (4EBn aromatic C(3) and C(5)),128.20 (4EBn ar-
omatic C(2) and C(6)),122.51 (aromatic C(1)),122.28 (4EBn aromatic
C(4)),114.91 (aromatic C(2)),112.38 (aromatic C(5)),83.65 (alkyne
ArC),77.86 (alkyne CH),69.73 (ArO CH2),69.41 (ArO CH2),66.19
G
J
U
J
ACHTREUNG
J
ACHTREUNG
J
ACHTREUNG
J
ACHTREUNG
J
A
Thin layer chromatography (TLC) was performed on silica gel plates
(Sigma-Aldrich) with UV indicator and the reported eluent. High-pres-
sure liquid chromatography (HPLC) in THF (1 mLminꢁ1) using a Shi-
madzu LC-10 AT liquid chromatograph using equipped with a Perkin-
Elmer LC-100 column oven at 408C,Shimadzu SPD-10 A UV/Vis
(254 nm) and RID-10 A refractive index detectors,Nelson Analytical 900
Series integrator data station and two American Polymer Standards AM
GPC gel columns of 500 Š (5 mm) and 10000 Š (5 mm). Gel permeation
chromatography (GPC) in THF (1 mLminꢁ1) using a Shimadzu LC-
10 AT liquid chromatograph equipped with a SIL-10 AD auto injector,
CTO-10 A column oven at 408C,detection and data collection as for
HPLC and two American Polymer Standards AM GPC gel columns of
500 Š (10 mm),10000 Š (10 mm) and 100000 Š (10 mm). Relative molec-
ular weights were determined according to a calibration with narrow pol-
ystyrene standards (American Polymer Standards). MALDI-TOF Mass
spectrometry was performed on a PerSeptive Biosystems Voyager-DE in
linear mode. Unless otherwise noted,all measurements were made using
2,5-dihydroxybenzoic acid as matrix. High-resolution electrospray ioniza-
tion (HRMS-ESI) and chemical ionization (HRMS-CI) mass spectra
measured at the Mass Spectrometry Facility of the Department of Chem-
istry at the University of Pennsylvania.
AHCTREUNG
A
G
J
ACHTREUNG
AHCTREUNG
(4EBn ArCH2O),32.27 (ArOCH
30.03 (ArOCH2(CH2)10),30.00 (ArOCH
(CH2)10),29.95 (ArOCH 2(CH2)10),29.76 (ArOCH
(ArOCH2(CH2)10),29.70 (ArOCH 2(CH2)10),29.55 (ArOCH
29.43 (ArOCH2(CH2)10),26.36 (ArOCH 2(CH2)10),26.32 (ArOCH
(CH2)10),23.03 (ArOCH 2(CH2)10),14.44 (ArO (CH2)11CH3); HRMS-ESI:
m/z: calcd for C40H60O4Na: 627.4389; found: 627.4398 [M+Na]+.
4-Ethynylbenzyl 3,4-bis(5,5,6,6,7,7,8,8,9,9,10,10,11,11,12,12,12-heptadeca-
fluorododecan-1-yloxy)benzoate [(3,4)12F8G1-4EBn]: solution of
(3,4)12F8G1-CO2H (520 mg,0.47 mmol),4-ethynylbenzyl alcohol
A
N
A
N
-
2
A
N
ACHTREUNG
A
N
ACHTREUNG
A
N
-
2
A
N
ACHTREUNG
A
AHCTREUNG
(74.8 mg,0.56 mmol),DPTS (36.1 mg,0.12 mmol) and DCC (125.4 mg,
0.61 mmol) in a,a,a-trifluorotoluene (5 mL) was stirred at 558C for 16 h.
A colorless precipitate was removed by filtration of the crude reaction
mixture. The filtrate was evaporated to dryness under reduced pressure.
The crude monomer was subjected to chromatography on silica gel using
Melting point determinations using a uni-melt capillary melting point ap-
paratus (Arthur H. Thomas Company,Philadelphia,PA,USA) are re-
ported as uncorrected values. Thermal transitions were measured on a
Thermal Analysis (TA) Instruments 2920 modulated differential scanning
calorimeter or DSC Q100 differential scanning calorimeter (DSC) with
refrigerated cooling system under nitrogen. In all cases,the heating and
cooling rates were 108Cminꢁ1 unless otherwise noted. First-order transi-
tion temperatures are reported as the maximum and minimum of their
endothermic and exothermic peak,respectively. Glass transition tempera-
tures (Tg) are reported as the middle of the change in heat capacity.
Indium was the calibration standard. An Olympus BX51 optical polar-
CH2Cl2. Freeze drying from benzene provided
(450 mg,78%). TLC (silica gel,CH 2Cl2): Rf =0.20; HPLC (THF): 99+
pure; 1H NMR (500 MHz,CDCl 3,25 8C,TMS):
d=7.70 (dd,
(H,H)=8.5, 4J
(H,H)=2.0 Hz,1H; aromatic C(6) H),7.56 (d, (H,H)=
2.0 Hz,1H; aromatic C(2) H),7.51 (d, (H,H)=8.3 Hz,2H; 4EBn aro-
matic C(3)H and C(5)H),7.39 (d, (H,H)=8.3 Hz,2H; 4EBn aromatic
C(2)H and C(6)H),6.87 (d, (H,H)=8.5 Hz,1H; aromatic C(5) H),5.33
(s,2H; 4EBn ArC H2O),4.08 (t, (H,H)=5.7 Hz,2H; ArOC H2),4.07 (t,
(H,H)=5.7 Hz,2H; ArOC H2),3.09 (s,1H; alkyne C H),2.17 (m,4H;
ArOCH2CH2),1.91 (m,4H; ArO (CH2)2CH2),1.83 (m,4H; ArO-
(CH2)3CH2); 13C NMR (125 MHz,CDCl 3,25 8C,TMS):
d=166.41
(3,4)12F8G1-4EBn
%
3J
A
G
J
ACHTREUNG
J
ACHTREUNG
J
ACHTREUNG
J
ACHTREUNG
J
ACHTREUNG
J
ACHTREUNG
ized microscope (10”/50” magnification) equipped with
a Mettler
AHCTREUNG
Toledo FP82HT hot stage and Mettler Toledo FP90 central processor
was used to verify thermal transitions and characterize anisotropic tex-
tures.
AHCTREUNG
(CO2CH2),153.33 (aromatic C(3)),148.61 (aromatic C(4)),137.33 (4EBn
aromatic C(1)),132.69 (4EBn aromatic C(3) and C(5)),128.28 (4EBn ar-
omatic C(2) and C(6)),124.33,122.87 (aromatic C(1)),122.34 (4EBn aro-
matic C(4)),114.47 (aromatic C(2)),111.13 (aromatic C(5)),83.59
(alkyne ArC),77.94 (alkyne CH),68.79 (ArO CH2),68.56 (ArO CH2),
X-Ray diffraction measurements were performed with CuKa1 radiation
from a Bruker-Nonius FR-591 rotating anode X-ray source with a 0.2”
2.0 mm2 filament operated at 3.4 kW. The beam was collimated and fo-
cused by a single bent mirror and sagitally focusing Ge(111) monochro-
R
66.34 (4EBn ArCH2O),30.96 (ArOCH
17.68 (ArOCH2
(CH2)3); 19F NMR (470 MHz,CDCl 3,25 8C,CFCl exter-
nal standard): d=ꢁ81.44 (t,
ꢁ115.17 (t, (F,F)=14.1 Hz; ArO
(CH2)4CF2 (CH2)4CF2
(CF2)6), ꢁ122.60 (s; ArO
(CH2)4CF2 (CH2)4CF2
(CF2)6), ꢁ124.04 (s; ArO
(CH2)4CF2(CF2)6).
4-Ethynylbenzyl
4EBn]: A solution of
A
G
2
mator,resulting in a 0.2”0.2 mm spot on a Bruker-AXS Hi-Star multi-
wire area detector. To minimize attenuation and background scattering,
an integral vacuum was maintained along the length of the flight tube
and the sample chamber. Samples were kept inside a Linkham hot stage
and controlled within ꢂ0.18C. Oriented fibers were obtained fro the
liquid crystalline phase. Both bulk and fiber samples were held in Linde-
man-type capillaries during X-ray experiments. Electron density profiles
were computed using programs developed by our laboratories with Sili-
con graphics (SGI) computers. Molecular models were constructed using
Materials Studio (Accelrys Inc.,San Diego,CA,USA) software suite.
AHCTREUNG
3
J
A
G
N
J
A
ACHTREUNG
A
G
A
ACHTREUNG
A
G
A
ACHTREUNG
A
ACHTREUNG
3,4,5-tris(dodecan-1-yloxy)benzoate
[(3,4,5)12G1-
AHCTREUNG
benzyl alcohol (355.4 mg,2.7 mmol),DPTS (159.8 mg,0.5 mmol) and
DCC (605.0 mg,2.9 mmol) in dry CH Cl2 (10 mL) was stirred for 24 h. A
2
Synthesis
colorless precipitate was removed by filtration of the crude reaction mix-
ture. The filtrate was evaporated to dryness under reduced pressure. The
crude monomer was subjected to chromatography on silica gel using hex-
anes/CH2Cl2 1:1. Precipitated the monomer from CH2Cl2 into MeOH and
collected it by filtration. Freeze drying from benzene provided
4-Ethynylbenzyl 3,4-bis(dodecan-1-yloxy)benzoate [(3,4)12G1-4EBn]: A
solution of (3,4)12G1-CO2H (1.48 g,3.0 mmol),4-ethynylbenzyl alcohol
N
(492.4 mg,3.2 mmol),DPTS (178.9 mg,0.6 mmol) and DCC (751.2 mg,
3.6 mmol) in dry CH2Cl2 (30 mL) was stirred for 15 h. A colorless precip-
itate was removed by filtration of the crude reaction mixture. The filtrate
was evaporated to dryness under reduced pressure. The crude monomer
was subjected to chromatography on silica gel using CH2Cl2. Precipitated
the monomer from CH2Cl2 into MeOH and collected it by filtration.
A
Rf =0.72; HPLC (THF): 99+ % pure; H NMR (500 MHz,CDCl 3,25 8C,
TMS): d=7.51 (d, J(H,H)=8.3 Hz,2H; 4EBn aromatic C(3) H and
C(5)H),7.38 (d, (H,H)=8.4 Hz,2H; 4EBn aromatic C(2) and
C(6)H),7.28 (s,2H; aromatic C(2) H and C(6)H),5.34 (s,2H; 4EBn
ArCH2O),4.02 (t, (H,H)=6.6 Hz,2H; ArOC H2),4.00 (t, (H,H)=
6.5 Hz,4H; ArOC H2),3.09 (s,1H; alkyne C H),1.81 (m,4H; Ar-
AHCTREUNG
J
A
H
Freeze drying from benzene provided
TLC (silica gel,hexanes/CH 2Cl2 1:1): Rf =0.47; HPLC (THF): 99+ %
pure; 1H NMR (500 MHz,CDCl 3,25 8C,TMS): d=7.67 (dd, 3J
(H,H)=
A
J
A
J
ACHTREUNG
AHCTREUNG
5740
www.chemeurj.org
ꢀ 2006 Wiley-VCH Verlag GmbH & Co. KGaA,Weinheim
Chem. Eur. J. 2006, 12,5731 – 5746

Dendronized Polyphenylacetylenes
FULL PAPER
OCH2CH2),1.74 (m,2H; ArOCH 2CH2),1.47 (m,6H; ArO
A
CH2Cl2 1:3!1:9. After removal of solvent from the collected product,
the isolated solid was dissolved in CH2Cl2 (20 mL) and precipitated into
cold methanol. Freeze drying from benzene provided the monomer as a
1.34 (m,overlapped),1.27 (overlapping s,48H; ArO
(t, J(H,H)=6.8 Hz,9H; ArO
A
ACHTREUNG
G
N
,
3
258C,TMS): d=166.54 (CO2CH2),153.01 (aromatic C(3) and C(5)),
143.16 (aromatic C(4)),137.22 (4EBn aromatic C(1)),132.69 (4EBn aro-
matic C(3) and C(5)),128.23 (4EBn aromatic C(2) and C(6)),125.03 (ar-
omatic C(1)),122.39 (4EBn aromatic C(4)),109.86 (aromatic C(2) and
C(6)),83.62 (alkyne Ar C),77.97 (alkyne CH),73.31 (ArO CH2),73.26
white solid (2.08 g,91%). [ a]D21 = +7.68 (c=1.16 in THF); TLC (silica
1
gel,hexanes/CH Cl2 1:6): Rf =0.33; HPLC (THF): 99+ % pure; H NMR
2
(500 MHz,CDCl 3,25 8C,TMS): d=7.52 (d, J
aromatic C(3)H and C(5)H),7.37 (s,2H; aromatic C(2) H and C(6)H),
7.36 (d, J(H,H)=8.4 Hz,2H; 4EBn aromatic C(2) H and C(6)H),7.31 (d,
(H,H)=8.6 Hz,4H; aromatic C(2 ’)H and C(6’)H),7.26 (d,
8.4 Hz,2H; 4EBn aromatic C(2 ’)H and C(6’)H),6.89 (d,
8.7 Hz,4H; aromatic C(3 ’)H and C(5’)H),6.89 (d,
aromatic C(3’)H and C(5’)H),5.32 (s,2H; 4EBn ArC H2O),5.04 (s,4H;
ArCH2O),5.03 (s,2H; ArC H2O,), 3.84 (dd, 3J(H,H)=6.0, 2J
(H,H)=
9.0 Hz,2H; ArOC H2),3.80 (dd, 3J(H,H)=6.0, 2J
(H,H)=9.0 Hz,1H;
ArOCH2),3.75 (dd, 3J(H,H)=6.6, 2J
(H,H)=9.0 Hz,2H; ArOC H2),3.71
(dd, 3J(H,H)=6.6, 2J
(H,H)=9.0 Hz,1H; ArOC H2),3.10 (s,1H; alkyne
CH),1.88 (m,3H; ArOCH 2CH),1.59 (m,2H; ArOCH 2CH(CH3)CH2),
1.58 (m,1H; ArOCH 2CH(CH3)CH2),1.29 (m,2H; ArOCH 2CH-
(CH3)CH2),1.27 (m,1H; ArOCH 2CH(CH3)CH2),1.03 (d, (H,H)=
6.8 Hz,6H; ArOCH 2CH(CH3)),1.02 (d, (H,H)=7.0 Hz,3H;
ArOCH2CH(CH3)),0.97 (t, (H,H)=7.5 Hz,6H; ArOCH 2CH-
(CH3)CH2CH3),0.97 (t, (H,H)=7.4 Hz,3H; ArOCH 2CH-
(CH3)CH2CH3); 13C NMR (125 MHz,CDCl 3,25 8C,TMS): d=166.27
A
AHCTREUNG
(ArOCH2),66.45 (4EBn Ar CH2O),32.26 (ArOCH
(ArOCH2(CH2)10),29.98 (ArOCH 2(CH2)10),29.96 (ArOCH
29.94 (ArOCH2(CH2)10),29.79 (ArOCH 2(CH2)10),29.77 (ArOCH
(CH2)10),29.69 (ArOCH 2(CH2)10),29.65 (ArOCH 2(CH2)10),26.41
(ArOCH2(CH2)10),23.02 (ArOCH 2(CH2)10),14.44 (ArO (CH2)11CH3);
ACHTREUNG
J
A
J
J
ACHTREUNG
A
N
ACHTREUNG
ACHTREUNG
A
N
-
2
J(H,H)=8.6 Hz,2H;
T
A
N
ACHTREUNG
A
N
ACHTREUNG
A
ACHTREUNG
UV/VIS (hexanes): lmax (e)=203 (68000),220 (53000),241 (32000),251
(31000),266 nm (19000 mꢁ1 cmꢁ1); HRMS-ESI: m/z: calcd for
C52H84O5Na: 811.6216; found: 811.6221 [M+Na]+.
A
ACHTREUNG
A
ACHTREUNG
A
ACHTREUNG
AHCTREUNG
4-Ethynylbenzyl 3,4-bis[(4’-dodecan-1-yloxy)benzyloxy]benzoate [(4-
3,4)12G1-4EBn]: A 100 mL flask equipped with a magnetic stir bar was
AHCTREUNG
A
G
J
ACHTREUNG
used to prepare a solution of (4-3,4)12G1-CO2H (1.64 g,2.3 mmol),4-
N
A
J
ACHTREUNG
ethynylbenzyl alcohol (357.4 mg,2.7 mmol),DPTS (155.0 mg,0.5 mmol)
and DCC (622.2 mg,3.01 mmol) in dry CH 2Cl2 (20 mL). The reaction
was sealed with a rubber septum and left stirring for 16 h. The reaction
mixture was filtered to remove the insoluble urea product,and the fil-
trate was evaporated to dryness under reduced pressure. The resulting
solid was subjected to chromatography on silica gel using hexanes/
CH2Cl2 3:1. After removal of solvent form the collected product,the iso-
lated solid was dissolved in CH2Cl2 (10 mL) and precipitated into cold
methanol. Freeze drying from benzene provided the monomer as a white
solid (1.82 g,95%). TLC (silica gel,hexanes/CH 2Cl2 3:1): Rf =0.12;
HPLC (THF): 99+ % pure; 1H NMR (500 MHz,CDCl 3,25 8C,TMS):
A
J
ACHTREUNG
A
J
ACHTREUNG
AHCTREUNG
(CO2CH2),159.60 (4EBn aromatic C(4’)),153.01 (aromatic C(3) and
C(5)),143.16 (aromatic C(4)),137.22 (4EBn aromatic C(1)),132.69
(4EBn aromatic C(3) and C(5)),130.60 (aromatic C(2’) and C(6’)),
129.77 (aromatic C(1’)),129.45 (aromatic C(2’) and C(6’)),128.89 (aro-
matic C(1’)),128.23 (4EBn aromatic C(2) and C(6)),125.03 (aromatic
C(1)),122.39 (4EBn aromatic C(4)),114.89 (aromatic C(3’) and C(5’)),
114.54 (aromatic C(3’) and C(5’)),109.86 (aromatic C(2) and C(6)),83.62
(alkyne ArC),77.97 (alkyne CH),75.06 (Ar CH2O),73.31 (ArO CH2),
73.26 (ArOCH2),71.52 (Ar CH2O),66.45 (4EBn Ar CH2O),35.10 (Ar-
d=7.65 (overlapped d,
(overlapped dd, 3J(H,H)=8.8, 4J
7.50 (d, J(H,H)=8.0 Hz,2H; 4EBn aromatic C(3) H and C(5)H),7.36 (d,
(H,H)=8.0 Hz,2H; 4EBn aromatic C(2) and C(6)H),7.33 (d,
(H,H)=8.1 Hz,2H; aromatic C(2 ’)H and C(6’)H),7.32 (d, (H,H)=
(H,H)=8.9 Hz,1H;
(H,H)=8.4 Hz,2H; aromatic C(3 ’)H and
(H,H)=8.3 Hz,2H; aromatic C(3 ’)H and C(5’)H),5.30
(s,2H; 4EBn ArC H2O),5.13 (s,2H; ArC H2O),5.09 (s,2H; ArC H2O,),
3.95 (t, J(H,H)=6.6 Hz,4H; ArOC H2),3.08 (s,1H; alkyne C H),1.78
(m,4H; ArOCH 2CH2),1.45 (m,4H; ArO (CH2)2CH2),1.32 (overlapped
m),1.27 (overlapping s,32H; ArO (CH2)3(CH2)8),0.89 (t, (H,H)=
6.4 Hz,6H; ArO
(CH2)11CH3); 13C NMR (125 MHz,CDCl 3,25 8C,TMS):
J
ACHTREUNG
A
ACHTREUNG
OCH2CH),26.52 (ArOCH 2CH
N
G
ACHTREUNG
16.88 ArOCH2CH(CH3)),11.66 (ArOCH 2CH
A
ACHTREUNG
J
J
U
H
(hexanes): lmax (e)=230 (68000),251 (24000),270 nm (18000 mꢁ1 cmꢁ1);
MALDI-TOF: m/z: calcd for C52H60O8Na: 835.42; found: 836.44
[M+Na]+.
J
ACHTREUNG
8.0 Hz,2H; aromatic C(2 ’)H and C(6’)H),6.93 (d,
aromatic C(5)H),6.88 (d,
C(5’)H),6.86 (d, J
J
ACHTREUNG
J
ACHTREUNG
ACHTREUNG
4-Ethynylbenzyl 3,4,5-tris[(4’-dodecan-1-yloxy)benzyloxy]benzoate [(4-
3,4,5)12G1-4EBn]: A 50 mL flask equipped with a magnetic stir bar was
ACHTREUNG
used to prepare a solution of (4-3,4,5)12G1-CO2H (1.75 g,1.8 mmol),4-
T
AHCTREUNG
ethynylbenzyl alcohol (287.9 mg,2.2 mmol),DPTS (519.7 mg 1.8 mmol)
A
N
J
ACHTREUNG
and DCC (441.7 mg,2.1 mmol) in dry CH Cl2 (10 mL). The reaction was
2
ACHTREUNG
sealed with a rubber septum and left stirring for 13 h. The reaction mix-
ture was filtered to remove the insoluble urea product,and the filtrate
was evaporated to dryness under reduced pressure. The resulting solid
was subjected to chromatography on silica gel using hexanes/CH2Cl2 1:2.
After removal of solvent from the collected product,the isolated solid
was dissolved in CH2Cl2 (10 mL) and precipitated into cold methanol.
Freeze drying from benzene provided the monomer as a white solid
(1.55 g,79%). TLC (silica gel,hexanes/CH 2Cl2 1:2): Rf =0.29; HPLC
(THF): 99+ % pure; 1H NMR (500 MHz,CDCl 3,25 8C,TMS): d=7.51
d=166.33 (CO2CH2),159.42 (aromatic C(4’)),159.37 (aromatic C(4’)),
153.69 (aromatic C(3)),148.83 (aromatic C(4)),137.39 (4EBn aromatic
C(1)),132.66 (4EBn aromatic C(3) and C(5)),129.46 (aromatic C(2’) and
C(6’)),129.22 (aromatic C(2’) and C(6’)),129.03 (aromatic C(1’)),128.68
(aromatic C(1’)),128.17 (4EBn aromatic C(1)),124.47 (aromatic C(6)),
123.03 (aromatic C(6)),122.30 (4EBn aromatic C(4)),116.42 (aromatic
C(2)),114.93 (aromatic C(3’) and C(5’)),114.87 (aromatic C(3’) and
C(5’)),113.90 (aromatic C(5)),83.66 (alkyne Ar C),77.87 (alkyne CH),
71.58 (ArCH2O),71.16 (Ar CH2O),68.44 (ArO CH2),68.42 (ArO CH2),
(d, J
aromatic C(2)H and C(6)H),7.33 (d, J
ic C(2)H and C(6)H,), 7.30 (d, J(H,H)=8.6 Hz,4H; aromatic C(2 ’)H
and C(6’)H),7.25 (d, J(H,H)=9.0 Hz,2H; aromatic C(2 ’)H and C(6’)H),
6.87 (d, J(H,H)=8.6 Hz,4H; aromatic C(3 ’)H and C(5’)H),6.75 (d, J-
(H,H)=8.6 Hz,2H; aromatic C(3 ’)H and C(5’)H),5.30 (s,2H; 4EBn
ArCH2O),5.03 (s,4H; ArC H2O),5.02 (s,2H; ArC H2O),3.95 (t,
(H,H)=6.6 Hz,4H; ArOC H2),3.91 (t, (H,H)=6.6 Hz,2H; ArOC H2),
3.08 (s,1H; alkyne C H),1.77 (m,6H; ArOCH 2CH2),1.45 (m,6H; ArO-
(CH2)2CH2),1.31 (m overlapped),1.27 (s overlapping,48H; ArO (CH2)2-
(CH2)8),0.88 (t, (H,H)=6.7 Hz,9H; ArO
(CH2)11CH3); 13C NMR
ACHTREUNG
66.22 (4EBn ArCH2O),32.27 (ArOCH
(CH2)10),29.98 (ArOCH 2(CH2)10),29.95 (ArOCH
(ArOCH2(CH2)10),29.77 (ArOCH 2(CH2)10),29.69 (ArOCH
29.66 (ArOCH2(CH2)10),29.64 (ArOCH 2(CH2)10),26.42 (ArOCH
(CH2)10),23.03 (ArOCH 2(CH2)10),14.44 (ArO (CH2)11CH3); UV/VIS
R
-
2
AHCTREUNG
A
N
ACHTREUNG
AHCTREUNG
A
N
ACHTREUNG
AHCTREUNG
A
N
-
2
AHCTREUNG
A
N
ACHTREUNG
AHCTREUNG
(hexanes): lmax (e)=203 (77000),222 (47000),241 (38000),252 (40000),
292 nm (11000mꢁ1 cmꢁ1); HRMS-ESI: m/z: calcd for C54H72O6Na:
839.5227; found: 839.5222 [M+Na]+.
J
A
J
ACHTREUNG
A
ACHTREUNG
4-Ethynylbenzyl 3,4,5-tris[4-((S)-3-methylbutan)-1-yloxy)benzyloxy]ben-
zoate [(4-3,4,5)AmylG1-4EBn]: A 50 mL flask equipped with a magnetic
A
J
A
ACHTREUNG
(125 MHz,CDCl 3,25 8C,TMS): d=166.23 (CO2CH2),159.38 (4EBn aro-
matic C(4’)),159.35 (4EBn aromatic C(4’)),152.98 (aromatic C(3) and
C(5)),143.08 (aromatic C(4)),137.17 (4EBn aromatic C(1)),132.66
(4EBn aromatic C(3) and C(5)),130.58 (aromatic C(2’) and C(6’)),
129.75 (aromatic C(1’)),129.54 (aromatic C(2’) and C(6’)),128.87 (aro-
matic C(1’)),128.21 (4EBn aromatic C(2) and C(6)),125.00 (aromatic
C(1)),122.36 (4EBn aromatic C(4)),114.81 (aromatic C(3’) and C(5’)),
stir bar was used to prepare a solution of (4-3,4,5)AmylG1-CO2H (1.97 g,
2.8 mmol),4-ethynylbenzyl alcohol (477.7 mg,3.3 mmol),DPTS (1.01 g,
A
3.4 mmol) and DCC (724.8 mg,3.5 mmol) in dry CH Cl2 (10 mL). The re-
2
action was sealed with a rubber septum and left stirring for 19 h. The re-
action mixture was filtered to remove the insoluble urea product,and the
filtrate was evaporated to dryness under reduced pressure. The resulting
solid was subjected to chromatography on silica gel using hexanes/
Chem. Eur. J. 2006, 12,5731 – 5746
ꢀ 2006 Wiley-VCH Verlag GmbH & Co. KGaA,Weinheim
www.chemeurj.org
5741

V. Percec et al.
114.45 (aromatic C(3’) and C(5’)),109.77 (aromatic C(2) and C(6)),83.59
(alkyne ArC),77.96 (alkyne CH),75.03 (Ar CH2O),71.47 (Ar CH2O),
68.39 (ArOCH2),68.31 (ArO CH2),66.43 (4EBn Ar CH2O),32.26
omatic C(2’)H),6.90 (dd, 3J
C(6’)H),6.84 (dd, 3J
(H,H)=8.0, J
6.82 (d, (H,H)=8.2 Hz,2H; aromatic C(5 ’)H),6.72 (d,
8.1 Hz,1H; aromatic C(5 ’)H),5.31 (s,2H; 4EBn ArC H2O),5.03 (s,2H;
ArCH2O),5.03 (s,1H; ArC H2O),3.98 (t, (H,H)=6.6 Hz,4H;
ArOCH2),3.94 (t, (H,H)=6.7 Hz,2H; ArOC H2),3.91 (t, (H,H)=
6.5 Hz,4H; ArOC H2),3.76 (t, (H,H)=6.5 Hz,2H ArOC H2),1.80 (m,
10H; ArOCH2CH2),1.70 (m,2H; ArOCH 2CH2),1.43 (m,10H; ArO-
(CH2)2CH2),1.35 (m,overlapped),1.26 (overlapping s,98H; ArO-
(CH2)2CH2 and ArO(CH2)3(CH2)8),0.88 (t, (H,H)=6.7 Hz,18H; ArO-
(CH2)11CH3); 13C NMR (125 MHz,CDCl 3,25 8C,TMS):
d=166.2
G
ACHTREUNG
4
ACHTREUNG
U
J
E
J
ACHTREUNG
(ArOCH2
29.96 (ArOCH2
(CH2)10),29.77 (ArOCH
(ArOCH2(CH2)10),26.41 (ArOCH
14.44 (ArO(CH2)11CH3); HRMS-ESI: m/z: calcd for C73H102O8Na:
1129.7472; found: 1127.7371 [M+Na]+.
4-Ethynylbenzyl 3,4-bis(3’,4’-bis(dodecan-1-yloxy)benzyloxy)benzoate
[(3,4-3,4)12G2-4EBn]: solution of (3,4-3,4)12G2-CO2H (1.51 g,
A
G
A
A
G
-
J
ACHTREUNG
2
A
G
A
J
U
J
ACHTREUNG
A
G
A
ACHTREUNG
AHCTREUNG
A
A
G
J
ACHTREUNG
AHCTREUNG
A
ACHTREUNG
(CO2CH2),152.9 (aromatic C(4)),149.6 (aromatic C(3’) or C(4’)),149.4
(aromatic C(3’) or C(4’)),149.3 (aromatic C(3’) or C(4’)),149.29 (aro-
matic C(3’) or C(4’)),143.0 (aromatic C(3) andC(5)),137.7 (4EBn aro-
matic C(1)),130.4 (4EBn aromatic C(2) and C(6)),129.6 (aromatic
C(1’)),128.2 (4EBn aromatic C(3) and C(5)),125.1 (aromatic C(1)),
122.4 (4EBn aromatic C(4)),121.4 (aromatic C(6’)),120.6 (aromatic
C(6’)),114.4 (aromatic C(5’)),113.9 (aromatic C(5’)),113.6 (aromatic
C(2’)),109.9 (aromatic C(2)),83.6 (alkyne Ar C),78.0 (alkyne CH),75.3
(ArCH2O),71.7 (Ar CH2O),69.6 (ArO CH2),69.5 (ArO CH2),69.2
1.4 mmol),4-ethynylbenzyl alcohol (230.1 mg,1.7 mmol),DPTS
(419.8 mg,1.4 mmol) and DCC (349.1 mg,1.7 mmol) in CH 2Cl2 (20 mL)
was stirred for 21 h. A colorless precipitate was removed by filtration of
the crude reaction mixture. The filtrate was evaporated to dryness under
reduced pressure. The crude monomer was subjected to chromatography
on silica gel using hexanes/CH2Cl2 1:4. Precipitated the monomer from
CH2Cl2 into MeOH and collected it by filtration. Freeze drying from ben-
zene provided
anes/CH2Cl2 1:2): Rf =0.16; HPLC (THF): 99+ % pure; 1H NMR
(500 MHz,CDCl 3,25 8C,TMS): d=7.65 (d, J(H,H)=1.9 Hz,1H; aro-
matic C(2)H),7.65 (dd, 3J(H,H)=8.8, 4J
(H,H)=1.9 Hz,1H; aromatic
(H,H)=8.2 Hz,2H; 4EBn aromatic C(3)
(H,H)=8.0 Hz,2H; 4EBn aromatic C(2)
A
(ArOCH2),66.4 (4EBn Ar CH2O),32.3 (ArOCH
(ArOCH2(CH2)10),30.07 (ArOCH 2(CH2)10),30.02 (ArOCH
29.9 (ArOCH2(CH2)10),29.8 (ArOCH 2(CH2)10),29.7 (ArOCH
29.68 (ArOCH2(CH2)10),26.5 (ArOCH 2(CH2)10),26.4 (ArOCH
23.0 (ArOCH2(CH2)10),14.4 (ArO (CH2)11CH3); UV/VIS (hexanes): lmax
ACHTREUNG
AHCTREUNG
A
N
ACHTREUNG
A
ACHTREUNG
A
N
ACHTREUNG
C(6)H),7.50 (d,
C(5)H),7.36 (d,
C(6)H),6.98 (d,
J
J
J
C
H
H
and
and
A
N
ACHTREUNG
A
N
ACHTREUNG
(e)=204 (176000),276 nm (25000 mꢁ1 cmꢁ1); MALDI-TOF: m/z: calcd
for C109H174O11Na: 1682.30; found: 1683.55 [M+Na]+.
J
A
J
ACHTREUNG
A
ACHTREUNG
4
N
G
4-Ethynylbenzyl 3,4-bis(3’,4’,5’-tris(dodecan-1-yloxy)benzyloxy)benzoate
A
J
A
[(3,4,5-3,4)12G2-4EBn]: A solution of (3,4,5-3,4)12G2-CO2H (1.06 g,
0.93 mmol),4-ethynylbenzyl alcohol (122.7 mg,0.93 mmol),DPTS
(100.9 mg,0.34 mmol) and DCC (192.9 mg,0.93 mmol) in CH
J
A
2Cl2
J
A
J
G
(10 mL) was stirred for 17 h. A colorless precipitate was removed by fil-
tration of the crude reaction mixture. The filtrate was evaporated to dry-
ness under reduced pressure. The crude monomer was subjected to chro-
matography on silica gel using hexanes/CH2Cl2 2:1!1:2. Precipitated the
monomer from CH2Cl2 into MeOH and collected it by filtration. Freeze
drying from benzene provided (3,4,5-3,4)12G2-4EBn (0.99 g,86%). TLC
(silica gel,hexanes/ethyl acetate 1:1): Rf =0.34; HPLC (THF): 99+ %
AHCTREUNG
U
G
J
ACHTREUNG
ACHTREUNG
(CO2CH2),153.67 (aromatic C(3)),149.76 (aromatic C(3’) or C(4’)),
149.71 (aromatic C(3’) or C(4’)),149.48 (aromatic C(3’) or C(4’)),149.40
(aromatic C(3’) or C(4’)),148.83 (aromatic C(4)),137.37 (4EBn aromatic
C(1)),132.66 (4EBn aromatic C(3) and C(5)),129.80 (aromatic C(1’)),
129.46 (aromatic C(1’)),128.14 (4EBn aromatic C(2) and C(6)),124.50
(aromatic C(2)),123.11 (aromatic C(1)),122.32 (4EBn aromatic C(4)),
120.57 (aromatic C(6’)),120.35 (aromatic C(6’)),116.34 (aromatic C(6)),
114.20 (aromatic C(5’)),114.17 (aromatic C(5’)),113.86 (aromatic C(2’)
and C(5)),113.66 (aromatic C(2’)),83.63 (alkyne Ar C),77.87 (alkyne
CH),71.73 (Ar CH2O),71.35 (Ar CH2O),69.75 (ArO CH2),69.66
pure; 1H NMR (500 MHz,CDCl 3,25 8C,TMS): d=7.68 (dd, 3J
8.8, 4J
(H,H)=2.0 Hz,1H; aromatic C(6) H),7.68 (d, (H,H)=1.9 Hz,
1H; aromatic C(2)H),7.51 (d, (H,H)=8.2 Hz,2H; 4EBn aromatic
C(3)H and C(5)H),7.36 (d, (H,H)=8.2 Hz,2H; 4EBn aromatic C(2) H
and C(6)H),6.94 (d, (H,H)=9.0 Hz,1H; aromatic C(5) H),6.65 (s,2H;
A
A
J
ACHTREUNG
J
ACHTREUNG
J
ACHTREUNG
J
ACHTREUNG
aromatic C(2’)H and C(6’)H),6.62 (s,2H; aromatic C(2 ’)H and C(6’)H),
5.32 (s,2H; 4EBn ArC H2O),5.10 (s,2H; ArC H2O),5.08 (s,2H;
ArCH2O),3.94 (t,
6.4 Hz,8H; ArOC H2),3.08 (s,1H; alkyne C H),1.76 (m,12H; Ar-
OCH2CH2),1.44 (m,12H; ArO (CH2)2CH2),1.27 (overlapped m and
overlapping s,96H; ArO (CH2)3(CH2)8),0.88 (t, (H,H)=6.9 Hz,18H;
ArO
(CH2)11CH3); 13C NMR (125 MHz,CDCl 3,25 8C,TMS): d=166.24
J
G
J(H,H)=
N
(ArOCH2),69.60 (ArO CH2),66.22 (4EBn Ar CH2O),32.27 (ArOCH
-
2
A
G
E
ACHTREUNG
N
G
A
A
G
J
ACHTREUNG
A
G
-
ACHTREUNG
2
A
N
(CO2CH2),153.70 (aromatic C(3)),153.61 (aromatic C(3’) and C(5’)),
148.79 (aromatic C(4)),138.43 (aromatic C(4’)),138.37 (aromatic C(4’)),
137.30 (4EBn aromatic C(1),132.67 (4EBn aromatic C(2) and C(6)),
132.05 (aromatic C(1’)),131.78 (aromatic C(1’)),128.12 (4EBn aromatic
C(3) and C(5)),124.62 (aromatic C(2)),123.24 (aromatic C(1)),122.34
(4EBn aromatic C(4)),116.34 (aromatic C(6)),113.88 (aromatic C(5)),
106.32 (aromatic C(2’) and C(6’)),106.07 (aromatic C(2’) and C(6’)),
(129000),222 (52000),240 (44000),252 (34000),283 nm
(14000mꢁ1 cmꢁ1); MALDI-TOF: m/z: calcd for C78H120O8Na: 1207.89;
found: 1208.78 [M+Na]+.
4-Ethynylbenzyl 3,4,5-tris(3’,4’-bis(dodecan-1-yloxy)benzyloxy)benzoate
[(3,4-3,4,5)12G2-4EBn]:
A solution of (3,4-3,4,5)12G2-CO2H (1.51 g,
0.98 mmol),4-ethynylbenzyl alcohol (168.0 mg,1.3 mmol),DPTS
(276.8 mg,0.94 mmol) and DCC (255.1 mg,1.2 mmol) in CH 2Cl2 (12 mL)
was stirred for 13 h. A colorless precipitate was removed by filtration of
the crude reaction mixture. The filtrate was evaporated to dryness under
reduced pressure. The crude monomer was subjected to chromatography
on silica gel using hexanes/CH2Cl2 2:3!1:4. Precipitated the monomer
from CH2Cl2 into MeOH and collected it by filtration. Freeze drying
83.60 (alkyne ArC),77.89 (alkyne
(ArCH2O),71.65 (Ar CH2O),69.53 (ArO CH2),69.48 (ArO CH2),66.26
(4EBn ArCH2O),32.82 (ArOCH 2(CH2)10),30.74 (ArOCH 2(CH2)10),
30.11 (ArOCH2(CH2)10),30.08 (ArOCH 2(CH2)10),30.02 (ArOCH
(CH2)10),29.82 (ArOCH 2(CH2)10),29.80 (ArOCH 2(CH2)10),29.72
(ArOCH2(CH2)10),26.51 (ArOCH 2(CH2)10),26.50 (ArOCH 2(CH2)10),
23.03 (ArOCH2(CH2)10),14.43 (ArO (CH2)11CH3). UV/VIS (hexanes):
CH),73.74 (ArO CH2),72.03
A
ACHTREUNG
A
N
-
2
A
N
ACHTREUNG
A
N
ACHTREUNG
A
ACHTREUNG
from benzene provided (3,4-3,4,5)12G2-4EBn (1.03 g,63%). TLC (silica
gel,hexanes/CH Cl2 1:2): Rf =0.28; HPLC (THF): 99+ % pure; H NMR
lmax (e)=208 (126000),240 (43000),251 (36000),290 nm (8000 mꢁ1 cmꢁ1);
MALDI-TOF: m/z: calcd for C102H168O10Na: 1576.25; found: 1576.67
[M+Na]+.
1
2
(500 MHz,CDCl 3,25 8C,TMS): d=7.52 (d, J
aromatic C(3)H and C(5)H),7.38 (s,2H; aromatic C(2) H and C(6)H),
7.36 (d, J(H,H)=8.7 Hz,2H; 4EBn aromatic C(2) H and C(6)H),6.98 (d,
(H,H)=1.8 Hz,2H; aromatic C(2 ’)H),6.95 (d, (H,H)=1.8 Hz,1H; ar-
A
G
4-Ethynylbenzyl 3,5-bis(3’,4’,5’-tris(dodecan-1-yloxy)benzyloxy)benzoate
J
G
J
A
[(3,4,5-3,5)12G2-4EBn]:
A
solution of (3,4,5-3,5)12G2-CO2H (1.38 g,
5742
www.chemeurj.org
ꢀ 2006 Wiley-VCH Verlag GmbH & Co. KGaA,Weinheim Chem. Eur. J. 2006, 12,5731 – 5746

Dendronized Polyphenylacetylenes
FULL PAPER
0.96 mmol),4-ethynylbenzyl alcohol (160.3 mg,1.2 mmol),DPTS
(159.8 mg,0.54 mmol) and DCC (263.1 mg,1.3 mmol) in CH 2Cl2 (10 mL)
was stirred for 20 h. A colorless precipitate was removed by filtration of
the crude reaction mixture. The filtrate was evaporated to dryness under
reduced pressure. The crude monomer was subjected to chromatography
on silica gel using hexanes/CH2Cl2 2:1!1:2. Precipitated the monomer
from CH2Cl2 into MeOH and collected it by filtration. Freeze drying
(ArOCH2
29.88 (ArOCH2
(CH2)10),29.74 (ArOCH
(ArOCH2(CH2)10),26.53 (ArOCH
14.43 (ArO(CH2)11CH3); UV/VIS (hexanes): lmax (e)=210 (154000),
C
N
G
U
U
A
G
ACHTREUNG
G
from benzene provided (3,4,5-3,5)12G2-4EBn (1.25 g,84%). TLC (silica
4-Ethynylbenzyl 3,5-bis{3’,4’-bis[(4’’-dodecan-1-yloxy)benzyloxy]benzyl-
1
gel,hexanes/CH Cl2 1:2): Rf =0.48; HPLC (THF): 99+ % pure; H NMR
2
oxy}benzoate [(4-3,4-3,5)12G2-4EBn]:
A solution of (4-3,4-3,5)12G1-
(500 MHz,CDCl 3,25 8C,TMS): d=7.51 (d, J
aromatic C(3)H and C(5)H),7.38 (d, J(H,H)=8.0 Hz,2H; 4EBn aromat-
ic C(2)H and C(6)H),7.32 (d, J(H,H)=2.3 Hz,2H; aromatic C(2), H and
C(6)H),6.82 (t, (H,H)=2.2 Hz,1H; aromatic C(5) H),6.61 (s,4H; aro-
matic C(2’)H and C(6’)H),5.34 (s,2H; 4EBn ArC H2O),4.95 (s,4H;
ArCH2O),3.97 (t, (H,H)=6.4 Hz,8H; ArOC H2),3.95 (t, (H,H)=
6.6 Hz,4H; ArOC H2),3.08 (s,1H; alkyne C H),1.79 (m,8H; Ar-
OCH2CH2),1.75 (m,4H; ArOCH 2CH2),1.47 (m,12H; ArO (CH2)2CH2),
1.32 (overlapped m),1.27 (overlapping s,96H; ArO (CH2)3(CH2)8),0.89
(t, J(H,H)=7.2 Hz,6H; ArO (CH2)11CH3),0.88 (t, (H,H)=6.8 Hz,12H;
ArO
(CH2)11CH3); 13C NMR (125 MHz,CDCl 3,25 8C,TMS): d=166.34
A
CO2H (1.03 g,0.69 mmol),4-ethynylbenzyl alcohol (106.8 mg,
0.80 mmol),DPTS (252.1 mg,0.86 mmol) and DCC (190.9 mg,
0.92 mmol) in CH2Cl2 (10 mL) was stirred for 43 h. A colorless precipi-
tate was removed by filtration of the crude reaction mixture. The filtrate
was evaporated to dryness under reduced pressure. The crude monomer
was subjected to chromatography on silica gel using hexanes/CH2Cl2
1:1!0:1. Precipitated the monomer from CH2Cl2 into MeOH and col-
lected it by filtration. Freeze drying from benzene provided (4-3,4-
3,5)12G2-4EBn (0.99 g,86%). TLC (silica gel,hexanes/CH 2Cl2 4:1): Rf =
0.38; HPLC (THF): 99+ % pure; 1H NMR (500 MHz,CDCl 3,25 8C,
AHCTREUNG
AHCTREUNG
J
ACHTREUNG
J
A
J
ACHTREUNG
AHCTREUNG
A
ACHTREUNG
A
G
J
ACHTREUNG
ACHTREUNG
TMS): d=7.51 (d, J
ACHTREUNG
(CO2CH2),160.22 (aromatic C(3) and C(5)),153.73 (aromatic C(3’) and
C(5’)),138.60 (aromatic C(4’)),137.00 (4EBn aromatic C(1)),132.72
(4EBn aromatic C(3) and C(5)),132.17 (aromatic C(1)),131.56 (aromatic
C(1’)),128.22 (4EBn aromatic C(2) and C(6)),122.42 (4EBn aromatic
C(4)),108.93 (aromatic C(2) and C(6)),107.67 (aromatic C(5)),106.74
(aromatic C(2’) and C(6’)),83.57 (alkyne Ar C),77.98 (alkyne CH),73.80
(ArOCH2),71.15 (Ar CH2O),69.57 (ArO CH2),66.63 (4EBn Ar CH2O),
C(5)H),7.37 (d,
C(6)H),7.32 (d,
J
A
H
J
A
U
ACHTREUNG
7.29 (d, J
(H,H)=1.2 Hz,2H; aromatic C(5 ’)H),6.94 (s,2H; aromatic C(2 ’)H),
6.93 (d, J(H,H)=2.1 Hz,2H; aromatic C(6 ’)H),6.87 (d, (H,H)=8.7 Hz,
4H; aromatic C(3’’)H and C(5’’)H),6.86 (d, (H,H)=8.7 Hz,4H; aro-
matic C(3’’)H and C(5’’)H),6.76 (t, J=2.3 Hz,1H; aromatic C(4) H),5.34
(s,2H; 4EBn ArC H2O),5.06 (s,4H; ArC H2O),5.05 (s,4H; ArC H2O),
4.94 (s,4H; ArC H2O),3.95 (t, (H,H)=6.6 Hz,4H; ArOC H2),3.94 (t,
(H,H)=6.6 Hz,4H; ArOC H2),1.78 (m,8H; ArOCH 2CH2),1.45 (m,
8H; ArO(CH2)2CH2),1.31 (overlapped m),1.27 (overlapping s,64H;
ArO(CH2)3(CH2)8),0.89 (t, (H,H)=6.9 Hz,12H; ArO (CH2)3-
(CH2)8CH3); 13C NMR (125 MHz,CDCl 3,25 8C,TMS):
d=166.35
(CO2CH2),160.18 (aromatic C(3) and C(5)),159.30 (aromatic (4’’)),
159.28 (aromatic C(4’’)),149.74 (aromatic C(4’)),149.50 (aromatic C(3’)),
137.04 (4EBn aromatic C(1)),132.71 (4EBn aromatic C(3) and C(5)),
132.11 (aromatic C(1)),129.97 (aromatic (2’’) and C(6’’)),129.46 (aro-
matic C(1’’)),129.34 (aromatic (2’’) and C(6’’)),128.26 (4EBn aromatic
C(2) and C(6)),122.44 (4EBn aromatic C(4)),121.35 (aromatic C(6’)),
115.80 (aromatic C(2’)),115.39 (aromatic C(5’)),114.83 (aromatic (3’’)
and C(5’’)),108.95 (aromatic C(2) and C(6)),107.70 (aromatic C(4)),
83.62 (alkyne ArC),77.98 (alkyne CH),71.68 (Ar CH2O),70.63
(ArCH2O),68.42 (ArO CH2),66.61 (4EBn Ar CH2O),32.27 (ArOCH
A
J
ACHTREUNG
G
J
ACHTREUNG
N
A
J
ACHTREUNG
A
ACHTREUNG
32.30 (ArOCH2
(CH2)10),30.11 (ArOCH
(ArOCH2(CH2)10),30.00 (ArOCH
29.74 (ArOCH2(CH2)10),29.71 (ArOCH
(CH2)10),26.48 (ArOCH 2(CH2)10),23.04 (ArOCH
C
N
-
2
U
G
ACHTREUNG
J
ACHTREUNG
E
A
ACHTREUNG
J
ACHTREUNG
-
2
AHCTREUNG
G
G
ACHTREUNG
A
N
J
E
ACHTREUNG
(CH2)11CH3); UV/VIS (hexanes): lmax (e)=209 (127000),240 (41000),
AHCTREUNG
252 (31000),306 nm (4000 mꢁ1 cmꢁ1); MALDI-TOF: m/z: calcd for
C102H168O10Na: 1576.25; found: 1576.50 [M+Na]+.
C
ACHTREUNG
AHCTREUNG
4-Ethynylbenzyl
3,4,5-tris(3’,4’,5’-tris(dodecan-1-yloxy)benzyloxy)ben-
C
A
ACHTREUNG
zoate [(3,4,5-3,4,5)12G2-4EBn]: A solution of (3,4,5-3,4,5)12G2-CO2H
(1.99 g,0.95 mmol),4-ethynylbenzyl alcohol (147.2 mg,1.1 mmol),DPTS
(254.8 mg,0.86 mmol) and DCC (243.1 mg,1.2 mmol) in CH 2Cl2 (20 mL)
was stirred for 16 h. A colorless precipitate was removed by filtration of
the crude reaction mixture. The filtrate was evaporated to dryness under
reduced pressure. The crude monomer was subjected to chromatography
on silica gel using hexanes/CH2Cl2 1:1!1:2. Precipitated the monomer
from CH2Cl2 into MeOH and collected it by filtration. Freeze drying
from benzene provided (3,4,5-3,4,5)12G2-4EBn (1.41 g,67%). TLC
(silica gel,hexanes/CH 2Cl2 1:2): Rf =0.38; HPLC (THF): 99+ % pure;
R
C
A
ACHTREUNG
C
ACHTREUNG
AHCTREUNG
-
2
T
G
ACHTREUNG
R
N
ACHTREUNG
N
G
-
2
1H NMR (500 MHz,CDCl 3,25 8C,TMS): d=7.52 (d, J
2H; 4EBn aromatic C(3)H and C(5)H),7.40 (s,2H; aromatic C(2) H and
C(6)H),7.35 (d, (H,H)=8.0 Hz,2H; 4EBn aromatic C(2) and
C(6)H),6.62 (s,4H; aromatic C(2 ’)H and C(6’)H),6.61 (s,2H; aromatic
C(2’)H and C(6’)H),5.32 (s,2H; 4EBn ArC H2O),5.05 (s,2H;
ArCH2O),5.03 (s,4H; ArC H2O),3.94 (t, (H,H)=6.6 Hz,4H;
ArOCH2),3.91 (t, (H,H)=6.4 Hz,6H; ArOC H2),3.88 (t, (H,H)=
6.4 Hz,6H; ArOC H2),3.77 (t, (H,H)=6.4 Hz,4H; ArOC H2),3.08 (s,
1H; alkyne CH),1.75 (m,18H; ArOCH 2CH2),1.42 (m,18H; ArO-
(CH2)2CH2),1.32 (overlapped m),1.27 (overlapping s,144H; ArO-
(CH2)3(CH2)8),0.89 (t, (H,H)=6.8 Hz,27H; ArO (CH2)11CH3);
A
N
G
ACHTREUNG
J
A
H
A
3,5)12G3-CO2H (665.4 mg,0.30 mmol),4-ethynylbenzyl alcohol (57.8 mg,
0.45 mmol),DPTS (127.5 mg,0.43 mmol) and DCC (85.6 mg,0.41 mmol)
in CH2Cl2 (5 mL) was stirred for 24 h. A colorless precipitate was re-
moved by filtration of the crude reaction mixture. The filtrate was evapo-
rated to dryness under reduced pressure. The crude monomer was sub-
jected to chromatography on silica gel using hexanes/CH2Cl2 6:4!0:1.
Precipitated the monomer from CH2Cl2 into MeOH and collected it by
filtration. Freeze drying from benzene provided (3,4-3,5-3,5)12G3-4EBn
(130.8 mg,19%). TLC (silica gel,hexanes/CH 2Cl2 1:2): Rf =0.56; HPLC
(THF): 99+ % pure; 1H NMR (500 MHz,CDCl 3,25 8C,TMS): d=7.49
J
ACHTREUNG
J
A
J
ACHTREUNG
J
ACHTREUNG
ACHTREUNG
A
G
J
G
ACHTREUNG
13C NMR (125 MHz,CDCl 3,25 8C,TMS): d=166.11 (CO2CH2),153.70
(aromatic C(4’)),153.43 (aromatic C(4’)),152.99 ((aromatic C(4)),143.31
(aromatic C(3) and C(5)),138.43 (aromatic C(1’)),138.38 (aromatic
C(1’)),137.13 (4EBn aromatic C(1)),132.74 (4EBn aromatic C(3) and
C(5)),132.70 (aromatic C(3’) and C(5’)),131.99 (aromatic C(3’) and
C(5’)),128.11 (4EBn aromatic C(2) and C(6)),125.34 (aromatic C(1)),
122.47 (4EBn aromatic C(4)),110.32 (aromatic C(2) and C(6)),106.82
(aromatic C(2’) and C(6’)),106.21 (aromatic C(2’) and C(6’)),83.57
(alkyne ArC),77.97 (alkyne CH),75.57 (Ar CH2O),73.76 (ArO CH2),
73.68 (ArOCH2),72.14 (Ar CH2O),69.53 (ArO CH2),69.35 (ArO CH2),
(d, J
(H,H)=8.2 Hz,2H; 4EBn C(2) H and C(6)H),7.30 (d,
2H; aromatic C(2)H and C(6)H),6.95 (d, (H,H)=1.8 Hz,4H; aromatic
(2’’)H),6.91 (dd, 3J(H,H)=8.2, 4J
(H,H)=1.8 Hz,2H; aromatic C-
(6’’)H),6.86 (d, (H,H)=8.2 Hz,4H; aromatic (5’’)H),6.80 (t,
(H,H)=2.3 Hz,1H; aromatic C(4) H),6.67 (d, (H,H)=2.2 Hz,4H; ar-
omatic C(2’)H and C(6’)H),6.57 (t, (H,H)=2.1 Hz,4H; aromatic
C(4’)H),5.33 (s,2H; 4EBn ArC H2O),5.00 (s,4H; ArC H2O),4.92 (s,
8H; ArCH2O),3.99 (t, J(H,H)=6.6 Hz,8H; ArOC H2),3.98 (t, J(H,H)=
ACHTREUNG
J
A
J
ACHTREUNG
J
ACHTREUNG
C
A
G
ACHTREUNG
A
J
A
ACHTREUNG
J
A
J
ACHTREUNG
J
ACHTREUNG
66.51 (4EBn ArCH2O),32.94 (ArOCH
A
-
2
A
G
A
C
ACHTREUNG
Chem. Eur. J. 2006, 12,5731 – 5746
ꢀ 2006 Wiley-VCH Verlag GmbH & Co. KGaA,Weinheim
www.chemeurj.org
5743

V. Percec et al.
6.6 Hz,8H; ArOC H2),3.07 (s,1H; alkyne C H),1.80 (m,16H; Ar-
OCH2CH2),1.46 (m,16H; ArO (CH2)2CH2),1.33 (overlapped m),1.26
(overlapping s,128H; ArO (CH2)3(CH2)8),0.88 (t, (H,H)=6.9 Hz,12H;
ArO(CH2)3(CH2)8CH3),0.87 (t, (H,H)=6.9 Hz,12H; ArO (CH2)3-
(CH2)8CH3); 13C NMR (125 MHz,CDCl 3,25 8C,TMS):
d=166.31
(CO2CH2),160.64 (aromatic C(3’) and C(5’)),160.14 (aromatic C(3) and
C(5)),149.72 (aromatic (3’’) or C(4’’)),149.51 (aromatic (3’’) or C-
(4’’)),139.04 (aromatic C(1’)),136.99 (4EBn aromatic C(1)),132.72
(4EBn aromatic C(3) and C(5)),132.19 (aromatic C(1)),129.58 (aromatic
(1’’)),128.22 (4EBn aromatic C(2) and C(6)),122.42 (4EBn aromatic
C(4)),120.93 (aromatic C(6’’)),114.20 (aromatic C(5’’)),114.08 (aromatic
(2’’)),108.95 (aromatic C(2) and C(6)),107.59 (aromatic C(4)),106.72
Poly{4-
{poly[(3,4)12G1-4EBn]}: A flame dried,argon filled Schlenk tube equip-
ped with a Teflon-coated magnetic stir bar was charged with [Rh
CPh)(nbd)(PPh3)2] (6.21 mg,0.008 mmol) and DMAP (11.17 mg,
0.091 mmol). Another flame dried,argon filled Schlenk tube was charged
with (3,4)12G1-4EBn (298.4 mg,0.493 mmol). The solids were degassed
by three cycles of evacuation followed by backfilling with argon. Via
glass syringe,dry THF (1.5 mL) was added to the monomer and was
added to the catalyst (1.6 mL). The monomer solution was transferred to
the catalyst solution at 228C under argon using a glass syringe. The reac-
tion was stirred under argon for 4 h. The reaction mixture was precipitat-
ed into cold MeOH (90 mL) and the polymer was collected by filtration.
Excess monomer was removed by filtration through a plug of basic Al2O3
using hexanes/CH2Cl2 10:1. Freeze-drying from benzene provided the
polymer (191.7 mg 71% based on conversion). 1H NMR (500 MHz,
CDCl3,25 8C,TMS): d=7.40 (brs,1H; aromatic C(5) H),7.38 (brs,1H;
aromatic C(2)H),6.90 (brs,2H; PPA C(2) H and C(6)H),6.59 (brs,3H;
PPA aromatic C(3)H and C(5)H and aromatic C(6)H),5.75 (brs,1H;
PPA cis-alkene),4.94 (brs,2H; PPA ArC H2O),3.81 (brs,4H; ArOC H2),
A
G
ACHTREUNG
ꢀ
(C
U
A
J
A
N
G
J
G
G
N
ACHTREUNG
AHCTREUNG
C
U
A
C
ACHTREUNG
ACHTREUNG
C
ACHTREUNG
A
ACHTREUNG
C
ACHTREUNG
(aromatic C(2’) and C(6’)),102.03 (aromatic C(4’)),83.60 (alkyne Ar C),
77.96 (alkyne CH),70.64 (Ar CH2O),69.75 (ArO CH2),69.67 (ArO CH2),
66.63 (4EBn ArCH2O),32.28 (ArOCH
(CH2)10),30.00 (ArOCH 2(CH2)10),29.82 (ArOCH
(ArOCH2(CH2)10),29.72 (ArOCH 2(CH2)10),29.70 (ArOCH
29.68 (ArOCH2(CH2)10),26.43 (ArOCH 2(CH2)10),26.41 (ArOCH
A
-
2
G
R
ACHTREUNG
N
R
ACHTREUNG
N
E
-
2
A
G
A
TOF: m/z: calcd for C154H240O16Na: 2368.79; found: 2369.85 [M+Na]+.
1.68 (brs,4H; ArOCH 2CH2),1.36 (brs,4H; ArO
32H; ArO(CH2)3(CH2)8),0.86 (t, J(H,H)=6.6 Hz,3H; ArO
(H,H)=6.6 Hz,6H; ArO (CH2)11CH3); Mn =61700, Mw/Mn =
ACHTREUNG
A
G
A
ACHTREUNG
4-Ethynylbenzyl 3,5-bis(3’,5’-bis{3’’,4’’-bis[(4’’’-dodecan-1-yloxy)benzyloxy]-
benzyloxy}benzyloxy)benzoate [(4-3,4-3,5-3,5)12G2-4EBn]: A solution of
(4-3,4-3,5-3,5)12G3-CO2H (435.0 mg; 0.14 mmol),4-ethynylbenzyl alco-
hol (23.1 mg,0.17 mmol),DPTS (69.2 mg,0.23 mmol) and DCC
(43.3 mg,0.21 mmol) in CH 2Cl2 (5 mL) was stirred for 26 h. A colorless
precipitate was removed by filtration of the crude reaction mixture. The
filtrate was evaporated to dryness under reduced pressure. The crude
monomer was subjected to chromatography on silica gel using hexanes/
CH2Cl2 3:7!0:1. Precipitated the monomer from CH2Cl2 into MeOH
and collected it by filtration. Freeze drying from benzene provided (4-
3,4-3,5-3,5)12G3-4EBn (194.0 mg,43%). TLC (silica gel,hexanes/CH 2Cl2
0.85 (t, J
A
ACHTREUNG
1.08.
General procedure for the polymerization of dendritic phenylacetylene
macromonomers by addition ofa catalyst solution to a solution ofmono-
mer
A
N
ꢀ
G
G
ACHTREUNG
AHCTREUNG
1:9): Rf =0.63; HPLC (THF): 99+ % pure; 1H NMR (500 MHz,CDCl
,
3
by three cycles of evacuation followed by backfilling with argon. Via
glass syringe,dry THF (2.8 mL) was added to the monomer and to the
catalyst (0.5 mL). The catalyst solution was transferred to the monomer
solution at 228C under argon using a glass syringe. The reaction was stir-
red under argon for 7.5 h. The reaction mixture was precipitated into
cold MeOH (90 mL). The polymer was collected by filtration and freeze-
dried from benzene to yield the polymer (216.7 mg,77% based on con-
version). Mn =192600, Mw/Mn =1.16.
258C,TMS): d=7.47 (d, J
ACHTREUNG
C(5)H),7.34 (d,
C(6)H),7.31 (d,
J
G
H
J
U
G
ACHTREUNG
7.30 (d, J
G
G
ACHTREUNG
A
G
A
J
ACHTREUNG
A
G
J
ACHTREUNG
A
G
J
ACHTREUNG
General procedure for the polymerization of dendritic phenylacetylene
macromonomers by addition solvent to a solid mixture ofmonomer and
catalyst
J
ACHTREUNG
J
ACHTREUNG
Poly{4-[3,4,5-tris(dodecan-1-yloxy)benzoyloxymethyl]phenylacetylene}
A
ACHTREUNG
{poly
A
equipped with
a
Teflon-coated magnetic stir bar was charged with
AHCTREUNG
ꢀ
A
(C CPh)
T
N
G
N
J
ACHTREUNG
(5.94 mg,0.007 mmol),and DMAP (10.23 mg,0.084 mmol). The solids
were degassed by three cycles of evacuation followed by backfilling with
argon. Via glass syringe,dry THF (7.6 mL) was added to the solid mix-
ture. The reaction was stirred at ambient temperature (i.e., ~238C) under
argon for 8 h. The reaction mixture was precipitated into cold MeOH
(125 mL) and collected by filtration. Excess monomer was removed by
filtering the polymer through a plug of silica gel using hexanes. Freeze-
U
G
J
G
ACHTREUNG
ACHTREUNG
C
N
C
ACHTREUNG
G
U
G
ACHTREUNG
C
ACHTREUNG
drying from benzene provided the polymer (216.7 mg,74% based on
C
C
C
(6’’’)),129.38 (aromatic
C
G
C
ACHTREUNG
1
conversion). H NMR (500 MHz,CDCl ,25 8C,TMS): d=7.10 (s,2H; ar-
3
omatic C(2)H and C(6)H),6.93 (brs,2H; PPA C(2) H and C(6)H),6.59
C(4)),121.34 (aromatic
115.72 (aromatic C
C
G
C
U
ACHTREUNG
(brs,2H; PPA aromatic C(3) H and C(5)H),5.64 (brs,1H; PPA
cis-
G
C
ACHTREUNG
alkene),4.93 (brs,2H; PPA ArC H2O),3.87 (brs,2H; ArOC H2),3.82
(brs,2H; ArOC H2),1.66 (brs,6H; ArOCH 2CH2),1.38 (brs,6H; ArO-
and C(6)),107.65 (aromatic C(4)),106.72 (aromatic C(2’) and C(6’)),
102.03 (aromatic C(4’)),83.61 (alkyne Ar C),77.97 (alkyne CH),71.66
(ArCH2O),71.60 (Ar CH2O),70.47 (Ar CH2O),70.43 (Ar CH2O),68.40
A
(CH2)3
U
J(H,H)=6.5 Hz,
N
AHCTREUNG
(ArOCH2),66.62 (4EBn Ar CH2O),32.28 (ArOCH
(ArOCH2(CH2)10),30.00 (ArOCH 2(CH2)10),29.97 (ArOCH
29.95 (ArOCH2(CH2)10),29.79 (ArOCH 2(CH2)10),29.70 (ArOCH
(CH2)10),29.66 (ArOCH 2(CH2)10),26.43 (ArOCH 2(CH2)10),23.04
(ArOCH2(CH2)10),14.47 (ArO (CH2)11CH3).
ACHTREUNG
A
G
ACHTREUNG
AHCTREUNG
T
N
-
2
AHCTREUNG
G
U
ACHTREUNG
TMS): d=7.47 (brs,1H; aromatic C(5) H),7.40 (brs,1H; aromatic
C(2)H),7.04 (d, J=5.0 Hz,4H; aromatic C(2 ’)H and C(6’)H),6.93 (brs,
2H; PPA C(2)H and C(6)H),6.65 (brs,3H; PPA aromatic C(3) H and
N
ACHTREUNG
General procedure for the polymerization of dendritic phenylacetylene
macromonomers by addition ofa monomer solution to a solution ofcata-
C(5)H and aromatic C(6)H),6.60 (d,
J(H,H)=5.0 Hz,4H; aromatic
A
lyst.
C(3’)H and C(5’)H),5.84 (brs,1H; PPA cis-alkene),4.96 (brs,2H; PPA
5744
www.chemeurj.org
ꢀ 2006 Wiley-VCH Verlag GmbH & Co. KGaA,Weinheim
Chem. Eur. J. 2006, 12,5731 – 5746

Dendronized Polyphenylacetylenes
FULL PAPER
ArCH2O),4.63 (brs,4H; ArC H2O),3.68 (brs,4H; ArOC H2),1.63 (brs,
Acknowledgements
4H; ArOCH2CH2),1.33 (brs,4H; ArO
(CH2)3(CH2)8),0.86 (t, J(H,H)=6.7 Hz,6H; ArO
Poly(4-{3,4,5-tris[4-((S)-3-methylbutan)-1-yloxy)benzyloxy]benzoyloxy-
methyl}phenylacetylene} {poly[(4-3,4,5)AmylG1-4EBn]}:
1H NMR
(500 MHz,CDCl 3,25 8C,TMS): d=7.11 (s,2H; aromatic C(2) H and
C(6)H),7.01 (d, (H,H)=7.7 Hz,6H; aromatic C(2 ’)H and C(6’)H),6.92
(d, J(H,H)=7.6 Hz,2H; PPA C(2) H and C(6)H),6.61 (d, (H,H)=
7.7 Hz,6H; aromatic C(3 ’)H and C(5’)H),6.48 (d, (H,H)=7.6 Hz,2H;
ACHTREUNG
A
G
A
ACHTREUNG
Financial support by the National Science Foundation (DMR-05-48559
and DMR-01-02459) is gratefully acknowledged.
AHCTREUNG
J
ACHTREUNG
[1] For reviews of dendronized polymers: a) A. D. Schlüter, Top. Curr.
Chem. 2005, 245,151–191; b) H. Frauenrath, Prog. Polym. Sci. 2005,
30,325–384; c) Dendrimers and Other Dendritic Polymers (Eds.:
A
J
ACHTREUNG
J
ACHTREUNG
PPA C(3)H and C(5)H),5.62 (brs,1H; PPA cis-alkene),4.97 (brs,2H;
PPA ArCH2O),4.62 (brs,3H; ArC H2O),4.56 (brs,3H; ArC H2O),3.57
(brs,3H; ArOC H2),3.49 (brs,3H; ArOC H2),1.69 (m,3H; Ar-
J. M. J. FrØchet,D. A. Tomalia),Wiley,Chichester,New York,
2001.
[2] Divergent synthesis of dendronized polymers: a) D. A. Tomalia,
P. M. Kirchhoff,US Patent 4694064, 1987; b) R. Yin,Y. Zhu,D. A.
Tomalia H. Ibuki, J. Am. Chem. Soc. 1998, 120,2678–2679.
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Percec,J. Heck, Polym. Bull. 1990, 24,255–262; b) B. Karakaya,W.
Claussen,K. Gessler,W. Saenger,A.-D. Schlüter, J. Am. Chem. Soc.
1997, 119,3296–3301.
OCH2CH),1.43 (m,3H; ArOCH
ArOCH2CH(CH3)CH2),0.89 (overlapping d and t,18H; ArOCH 2CH-
(CH3) and ArOCH2CH(CH3)CH2CH3).
Poly(4-{3,4,5-tris[4’-(dodecan-1-yloxy)benzyloxy]benzoyloxymethyl}phe-
nylacetylene {poly ,
[(4-3,4,5)12G1-4EBn]}: 1H NMR (500 MHz,CDCl
3
2CH
A
ACHTREUNG
A
ACHTREUNG
ACHTREUNG
A
258C,TMS): d=7.08 (brs,2H; aromatic C(2) H and C(6)H,), 6.99 (brs,
6H; aromatic C(2’)H and C(6’)H),6.88 (brs,2H; PPA C(2) H and
C(6)H),6.57 (brs,6H; aromatic C(3 ’)H and C(5’)H),6.43 (brs,2H; PPA
C(3)H and C(5)H),5.66 (brs,1H; PPA cis-alkene),4.97 (brs,2H; PPA
ArCH2O),4.60 (brs,6H; ArC H2O),3.65 (brs,6H; ArOC H2),1.60 (brs,
[4] Macromonomer approach for synthesis of dendronized polymers:
a) V. Percec,J. Heck,M. Lee,G. Ungar,A. Alvarez-Castillo,
J.
Mater. Chem. 1992, 2,1033–1039; b) G. Draheim,H. Ritter, Macro-
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Meijerink,A. W. M. Braum, J. Am. Chem. Soc. 1998, 120,9753–
9762.
6H; ArOCH2CH2),1.23 (brs,60H; ArO
(H,H)=9.2 Hz,3H; ArO (CH2)11CH3),0.86 (t,
ArO(CH2)11CH3).
Poly(4-{3,4-bis[3’,4’-bis(dodecan-1-yloxy)benzyloxy]benzoyloxymethyl}-
phenylacetylene) {poly
[(3,4-3,4)12G2-4EBn]}: 1H NMR (500 MHz,
A
ACHTREUNG
A
G
J
ACHTREUNG
[5] Dendronized polyarylacetylenes: a) T. Kaneko,T. Horie,M. Asano,
T. Aoki,E. Oikawa, Macromolecules 1997, 30,3118–3121; b) T.
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3509–3533; e) V. Percec,J. G. Rudick,M. Peterca,M. Wagner,M.
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12978–12979; b) V. Percec,C.-H. Anh,G. Ungar,D. J. P. Yeardley,
M. Mçller,S. S. Sheiko, Nature 1998, 391,161–164; c) V. Percec,C.-
H. Anh,W.-D. Cho,A. M. Jamieson,J. Kim,T. Leman,M. Schmidt,
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8619–8631; d) S. A. Prokhorova,S. S. Sheiko,M. Mçller,C.-H. Anh,
V. Percec, Macromol. Rapid Commun. 1998, 19,359–366; e) S. A.
ACHTREUNG
ACHTREUNG
AHCTREUNG
CDCl3,25 8C,TMS): d=7.10 (brs,2H; aromatic C(2) H and C(6)H),7.05
(brs,1H; aromatic C(5) H),6.91 (brs,2H; PPA C(2) H and C(6)H),6.72
(s,4H; aromatic C(2 ’)H and C(5’)H),6.67 (brs,2H; aromatic C(6 ’)H),
6.62 (brs,2H; PPA C(3) H and C(5)H),5.61 (brs,1H; PPA cis-alkene),
5.01 (brs,2H; PPA ArC H2O),4.61 (brs,4H; ArC H2O),3.73 (brs,8H;
ArOCH2),1.64 (brs,8H; ArOCH 2CH2),1.30 (brs,8H; ArO
1.23 (brs,64H; ArO (CH2)3(CH2)8),0.83 (t, (H,H)=6.9 Hz,6H; ArO-
(CH2)11CH3),0.80 (t, J(H,H)=6.6 Hz,6H; ArO (CH2)11CH3).
Poly(4-{3,4-bis[3’,4’,5’-tris(dodecan-1-yloxy)benzyloxy]benzoyloxyme-
(CH2)2CH2),
A
G
J
ACHTREUNG
A
N
ACHTREUNG
ACHTREUNG
thyl}phenylacetylene) {poly[(3,4,5-3,4)12G2-4EBn]}: 1H NMR (500 MHz,
CDCl3,25 8C,TMS): d=7.12 (brs,2H; aromatic C(2) H and C(6)H),7.09
(brs,1H; aromatic C(5) H),6.96 (brs,2H; PPA C(2) H and C(6)H),6.72
(s,4H; aromatic C(2 ’)H and C(6’)H),6.62 (brs,2H; PPA C(3) H and
C(5)H),5.75 (brs,1H; PPA cis-alkene),4.98 (brs,2H; PPA ArC H2O),
4.59 (brs,4H; ArC H2O),3.75 (brs,12H; ArOC H2),1.59 (brs,12H; Ar-
Prokhorova,S. S. Sheiko,C.-H. Anh,V. Percec,M. Mçller,
Macro-
molecules 1999, 32,2653–2660; f) S. A. Prokhorova,S. S. Sheiko,A.
Mourran,R. Azumi,U. Beginn,G. Zipp,C.-H. Anh,M. N. Holerca,
V. Percec,M. Mçller, Langmuir 2000, 16,6862–6867; g) A. Rapp,I.
OCH2CH2),1.28 (brs,12H; ArO
(CH2)2(CH2)9),0.83 (brs,18H; ArO
Poly(4-{3,5-bis[3’,4’,5’-tris(dodecan-1-yloxy)benzyloxy]benzoyloxyme-
ACHTREUNG
A
N
ACHTREUNG
ACHTREUNG
Schnell,D. Sebastiani,S. P. Brown,V. Percec,H. W. Spiess,
J. Am.
thyl}phenylacetylene {poly[(3,4,5-3,5)12G2-4EBn]}: 1H NMR (500 MHz,
CDCl3,25 8C,TMS): d=7.04 (brs,2H; aromatic C(2) H and C(6)H),6.97
(brs,2H; PPA C(2) H and C(6)H),6.81 (s,4H; aromatic C(2 ’)H and
C(6’)H),6.64 (brs,2H; PPA C(3) H and C(5)H),6.40 (brs,1H; aromatic
C(4)H),5.67 (brs,1H; PPA cis-alkene),4.99 (brs,2H; PPA ArC H2O),
4.57 (brs,4H; ArC H2O),3.72 (brs,12H; ArOC H2),1.62 (brs,12H; Ar-
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(CH2)9CH3).
Poly[4-(3,5-bis{3’,4’-bis[(4’’-dodecan-1-yloxy)benzyloxy]benzyloxy}ben-
A
N
ACHTREUNG
R
zoyloxymethyl)phenylacetylene] {poly[(4-3,4-3,5)12G2-4EBn]}: 1H NMR
(500 MHz,CDCl 3,25 8C,TMS): d=7.21 (brs,2H; aromatic C(2) H and
C(6)H),6.94 (brs,8H; aromatic C
matic C(2’)H or C(5’)H),6.67 (brs,4H; aromatic C(2 ’)H or C(5’)H),6.52
(brs,11H; aromatic C (3’’)H, C(5’’)H,C(6 ’)H,and C(5) H),5.72 (brs,1H;
PPA cis-alkene),4.53 (brs,14H; ArC H2O),3.61 (brs,8H; ArOC H2),
1.58 (brs,8H; ArOCH 2CH2),1.24 (brs,72H; ArO (CH2)2(CH2)9),0.86
(brs,12H; ArO (CH2)11CH3).
A
G
K. D. Singer,H.-W. Spiess,S. D. Hudson,H. Duan,
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Received: January 4,2006
Published online: May 16,2006
5746
www.chemeurj.org
ꢀ 2006 Wiley-VCH Verlag GmbH & Co. KGaA,Weinheim
Chem. Eur. J. 2006, 12,5731 – 5746