Core-perfluoroalkylated perylene diimides and naphthalene diimides: Versatile synthesis, solubility, electrochemistry, and optical properties

Article abstract of DOI:10.1021/jo100231j

By a strategy featuring perfluoroalkylation of the highly soluble intermediates and their further efficient transformations to target compounds, a versatile synthesis of core-perfluoroalkylated perylene diimides (PDIs) and naphthalene diimides (NDIs) was developed, and PDIs perfluoroalkylated at 1-position or 1,6-positions and core-perfluoroalkylated NDIs were first obtained. By esterification, perfluoroalkylation, hydrolysis, and condensation with amine, 1-perfluorooctyl-PDIs (7b, 7c, and 7e), 1,7-bis(perfluorooctyl)-PDIs (8a-c and 8e-g), 1,6-bis(perfluorooctyl)-PDIs (8-e), a mixture of 1,7-bis(trifluoromethyl)-PDIs and 1,6-bis(trifluoromethyl)-PDIs (11b and 11′b, 11d and 11′d, in a ratio of 19:1), 2-perfluorooctyl-NDIs (20a-d), and 2,6-bis(perfluorooctyl)-NDIs (21a-21d) were efficiently synthesized. Five valuable intermediates-1-perfluorooctylperylene dianhydride (5), 1,7-bis(perfluorooctyl)perylene dianhydride (6) 1,6-bis(perfluorooctyl) perylene dianhydride (6-), 2-perfluorooctylnaphthalene dianhydride (18), and 2,6-bis(perfluorooctyl) naphthalene dianhydride (19)-were also obtained, and they can condense with many amines to produce PDIs containing different functional side chains on the imide nitrogen atoms. Solubility, electrochemistry, and optical properties of the above core-perfluoroalkylated PDIs and NDIs were investigated. Core-perfluoroalkylated 8e, 8f, 8-e, mixture of 11d and 11′d, 20b, and 20d with excellent solubility in common organic solvents are competitive as candidates as solution processable semiconductors. Core-perfluoroalkylated PDIs and NDIs with experimental LUMO energy of 4.04-4.34 eV demonstrate strong electron accepting ability. For core-perfluoroalkylated PDIs, the maximum absorptions display blue shifts of 6-18 nm and the maximum molar extinction coefficients decrease obviously relative to those of unsubstituted PDIs, and they inherit the strong fluorescence from the PDIs family, which makes them promising fluorescent dyes.

Full text of DOI:10.1021/jo100231j

pubs.acs.org/joc
Core-Perfluoroalkylated Perylene Diimides and Naphthalene Diimides:
Versatile Synthesis, Solubility, Electrochemistry, and Optical Properties
Zhongyi Yuan,† Jing Li,† Yi Xiao,*,†,‡ Zheng Li,† and Xuhong Qian‡
†State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian 116012, China, and
‡State Key Laboratory of Bioreactor Engineering and Shanghai Key Laboratory of Chemical Biology,
East China University of Science and Technology, Shanghai 200237, China
xiaoyi@chem.dlut.edu.cn
Received February 12, 2010
By a strategy featuring perfluoroalkylation of the highly soluble intermediates and their further
efficient transformations to target compounds, a versatile synthesis of core-perfluoroalkylated
perylene diimides (PDIs) and naphthalene diimides (NDIs) was developed, and PDIs perfluoroalky-
lated at 1-position or 1,6-positions and core-perfluoroalkylated NDIs were first obtained. By
esterification, perfluoroalkylation, hydrolysis, and condensation with amine, 1-perfluorooctyl-
PDIs (7b, 7c, and 7e), 1,7-bis(perfluorooctyl)-PDIs (8a-c and 8e-g), 1,6-bis(perfluorooctyl)-
PDIs (80e), a mixture of 1,7-bis(trifluoromethyl)-PDIs and 1,6-bis(trifluoromethyl)-PDIs (11b and
110b, 11d and 110d, in a ratio of 19:1), 2-perfluorooctyl-NDIs (20a-d), and 2,6-bis(perfluorooctyl)-
NDIs (21a-21d) were efficiently synthesized. Five valuable intermediates;1-perfluorooctylpery-
lene dianhydride (5), 1,7-bis(perfluorooctyl)perylene dianhydride (6) 1,6-bis(perfluorooctyl)perylene
dianhydride (60), 2-perfluorooctylnaphthalene dianhydride (18), and 2,6-bis(perfluorooctyl) naphtha-
lene dianhydride (19);were also obtained, and they can condense with many amines to produce PDIs
containing different functional side chains on the imide nitrogen atoms. Solubility, electrochemistry,
and optical properties of the above core-perfluoroalkylated PDIs and NDIs were investigated. Core-
perfluoroalkylated 8e, 8f, 80e, mixture of 11d and 110d, 20b, and 20d with excellent solubility in
common organic solvents are competitive as candidates as solution processable semiconductors.
Core-perfluoroalkylated PDIs and NDIs with experimental LUMO energy of 4.04-4.34 eV demon-
strate strong electron accepting ability. For core-perfluoroalkylated PDIs, the maximum absorptions
display blue shifts of 6-18 nm and the maximum molar extinction coefficients decrease obviously
relative to those of unsubstituted PDIs, and they inherit the strong fluorescence from the PDIs family,
which makes them promising fluorescent dyes.
Introduction
of the major challenges in the field of organic semiconductors
is the development of high-mobility and environmentally
stable n-type materials.3 Perylene diimides (PDIs), naphtha-
lene diimides (NDIs), and their derivatives, with compact
and electron deficient cores, have demonstrated great
potential as n-type semiconductors in organic field-effect
transistors (OFETs).4-6 PDIs and their derivatives also
Organic semiconductors are an important class of ele-
ctronic materials that offer intriguing prospects for high
throughput, low-cost electronic circuitry on flexible sub-
strates.1,2 High-performance n-type (electron-transporting)
semiconductors are still rare compared to their high-
efficiency p-type (hole-transporting) counterparts, so one
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DOI: 10.1021/jo100231j
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Published on Web 04/05/2010
J. Org. Chem. 2010, 75, 3007–3016 3007
2010 American Chemical Society

Yuan et al.
JOCArticle
demonstrate wide applications in organic solar cells,7-9 light
harvesting systems,10,11 and fluorescent dyes.12-14 Though
N,N0-alkyl substituted PDIs and NDIs display electron
mobility as high as 2.1 and 6.2 cm2 V-1 s-1, respectively, in
OFETs,15-19 devices made from them are not air stable,
which hampers their further applications. At present, two
kinds of important and environmentally stable n-type mate-
rials were obtained via introducing electron-withdrawing
groups (such as F, CnF2nþ1, CN, etc.) to aromatic cores or
nitrogen atoms of PDIs and NDIs.20-25
As electron-withdrawing substituents in particular per-
fluoroalkyl groups can efficiently increase air stability and
electron mobility in many organic semiconductor plat-
forms,26-29 and perfluoroalkyl groups were introduced to
the imide sites of PDIs and NDIs in an earlier period, which
resulted in good devices performance.20-22,24,30 Then, in
2007, almost at the same time, we31 and Wang et al.32
attached two perfluoroalkyl groups to the bay area of PDIs0
core via directly coupling dibromo-substituted PDIs with
perfluoroalkyl iodide and obtained air-stable n-type semi-
conductors. However, this method just succeeded in a limited
amount. First, as is well-known, common PDIs including
dibromo-substituted PDIs have poor solubility in organic
solvents due to π-π stacking, so only dibromo-PDIs with a
large alkyl group at nitrogen atoms can be perfluoroalky-
lated effectively. Second, this method encounters a common
problem in the synthesis of all the bay-modified PDIs.
The precursor dibromo-PDIs contained two regioisomers
(1,6- and 1,7-diromo-PDIs), and they are difficult, if not
impossible, to isolate on a relatively large scale, due to
their poor solubility as well as their similar polarity. Thus,
further transformations will also produce a mixture of iso-
meric products which are difficult to purify. Although in
some cases isomerically pure 1,7-bis-substituted PDIs were
purified via repeated crystallization,33 the corresponding
1,6-isomers were rarely obtained.34
Core-perfluoroalkylated NDIs are also intriguing, be-
cause NDIs have even stronger electron accepting ability
than PDIs. However, Core-perfluoroalkylated NDIs have
not been available in the literature due to synthetic chal-
lenges. So it is interesting to develop a methodology suitable
for the syntheses of both core-perfluoroalkylated PDIs and
the corresponding NDIs. Ideally, the products can be manu-
factured on larger scale and the regioisomers can be effec-
tively isolated. Since direct pefluoroalkylation of PDIs and
NDIs with small alkyl groups at nitrogen atoms is imprac-
tical due to their bad solubility, a new strategy should be
adopted.
In a recent communication, by a new strategy featuring
trifluoromethylation of a highly soluble intermediate and its
further efficient transformation to target compounds, we
synthesized three regioisomerically pure bis(trifluoromethyl)-
substituted 3,4,9,10-perylene tetracarboxylic bis(benzimida-
zoles) and obtained the key intermediate mixture of
1,7-bis(trifluoromethyl)perylene dianhydride and 1,6-bis-
(trifluoromethyl)perylene dianhydride (10 and 100, in a ratio
of 10:1).35 In this paper, we extended the work to perfluoro-
octyl group substituted PDIs and NDIs, and a mixture of
1,7-bis(trifluoromethyl)-PDIs and 1,6-bis(trifluoromethyl)-
PDIs which were prepared with a mixture of 10 and 100 as
the reactant. With the above versatile synthesis, 1-perfluoro-
octyl-PDIs (7b, 7c, and 7e), 1,7-bis(perfluorooctyl)-PDIs
(8a-c, 8e-g), 1,6-bis(perfluorooctyl)-PDIs (80e), a mixture
of 1,7-bis(trifluoromethyl)-PDIs and 1,6-bis(trifluoromethyl)-
PDIs (11b and 110b, 11d and 110d, in a ratio of 19:1), 2-
perfluorooctyl-NDIs (20a-d), and 2,6-bis(perfluorooctyl)-
NDIs (21a-d) were synthesized, as shown in Schemes 1, 3,
and 4. Herein, PDIs perfluoroalkylated at 1-position or 1,6-
positions and core-perfluoroalkylated NDIs were first re-
ported. Meanwhile, five valuable intermediates 1-perfluorooc-
tylperylene dianhydride (5), 1,7-bis(perfluorooctyl)perylene
dianhydride (6), 1,6-bis(perfluorooctyl)perylene dianhydride
(60), 2-perfluorooctylnaphthalene dianhydride (18), and 2,6-
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SCHEME 1. Synthesis of Perfluorooctylated Perylene Diimides
SCHEME 2. Perfluorooctylation of 3,4,9,10-Tetra(n-
butoxycarbonyl)perylene
obtained, and they can condense with many amines to produce
PDIs containing different functional side chains on the imide
nitrogen atoms. In addition, the perfluorooctyl group was
introduced to 3,4,9,10-tetra(n-butoxycarbonyl)perylene (9)
directly in the presence of copper bronze as catalyst for the
first time, as shown in Scheme 2. Solubility, electrochemistry,
and optical properties of the above core-perfluoroalkylated
PDIs and NDIs were also investigated.
Results and Discussion
Synthesis. As shown in Scheme 1, to increase the solubility
of reactants used in the perfluoroalkylation, the highly
soluble intermediates 1-bromo-3,4,9,10-tetra(n-butoxycar-
bonyl)perylene (1) and a mixture of 1,7-dibromo-3,4,9,10-
tetra(n-butoxycarbonyl)perylene and 1,6-dibromo-3,4,9,10-
tetra(n-butoxycarbonyl)perylene (2 and 20, in a ratio of 4:1)
were selected as starting materials. After perfluorooctyla-
tion with a mixture of 2 and 20 as reactant, we found
regioisomers 1,7-bis(perfluorooctyl)-3,4,9,10-tetra(n-butoxy-
carbonyl)perylene (4) and 1,6-bis(perfluorooctyl)-3,4,9,10-
tetra(n-butoxycarbonyl)perylene (40) can be separated through
silica gel column chromatography, and they can be differen-
tiated by 1H NMR (Figure 1).
led to 3 in 23% yield. To our surprise, compounds 4 and 40
were also found in the above reaction mixture. The finding
suggested that perfluorooctylation of 9 may be done by
reacting perfluorooctyl iodide directly with 9. After many
attempts, it was found that the reaction between perfluoro-
octyl iodide and 9 can occur quickly in DMSO in the
presence of copper bronze at high temperature. For example,
9 can be converted to 3, 4, and 40 in 22%, 13%, and 10%
yield, respectively, at 190 °C in 2 h (Scheme 2). However,
The coupling reaction of 1 with perfluorooctyl iodide in
DMSO at 100 °C in the presence of copper bronze as catalyst
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FIGURE 1. Low-field section of the 1H NMR spectrum (400 MHz,
in CDCl3) of 4 (bottom) and 40(top).
SCHEME 3. Synthesis of Bis(trifluoromethyl)-Substituted
Perylene Diimides
FIGURE 2. Low-field section of the 1H NMR spectrum (400 MHz,
in CDCl3) for a mixture of 11b and 110b (bottom) and a mixture of
11d and 110d (top).
bis(trifluoromethyl)-PDIs mixtures (11b and 110b in a 64%
yield, 11d and 110d in a 70% yield, Scheme 3). 1,7-Bis(tri-
fluoromethyl)-PDIs and 1,6-bis(trifluoromethyl)-PDIs can-
not be separated through silica gel column chromatography,
but can be differentiated by 1H NMR (Figure 2), and a 19:1
ratio (11b:110b, 11d:110d) was indicated by 400 MHz NMR
spectroscopy.
A mixture of 2-bromonaphthalene dianhydride (12)
and 2,6- dibromonaphthalene dianhydride (13), with poor
solubility in common organic solvents, was synthesized
by bromination of naphthalene dianhydride according
to a literature method.23 As shown in Scheme 4, highly
soluble intermediates 2-bromo-1,4,5,8-tetra(n-butoxycarbo-
nyl)naphthalene (14) and 2,6-dibromo-1,4,5,8-tetra(n-but-
oxycarbonyl)naphthalene (15) were synthesized by reaction
of a mixture of 12 and 13 with 1-bromobutane in a 29% and
24% yield, respectively (overall for bromination and esteri-
fication), in aqueous KOH in the presence of tetraoctyl
ammonium bromide as phase transfer catalyst. After puri-
fication through silica gel column chromatography, inter-
mediate 15 as a viscous liquid still contained several
impurities, and HPLC results indicated that 15 with chro-
matographic purity 83% included at least six impurities (see
the Supporting Information), and it was used directly in the
next reaction without further purification; with preparative
HPLC, we successfully obtained a small amount of pure 15,
which was satisfactorily characterized by NMR.
The coupling reaction of 14 or 15 with perfluorooctyl
iodide in DMSO at 80 °C in the presence of copper bronze as
catalyst led to 16 or 17 in a 66% or 61% yield, respectively.
However direct perfluorooctylation of 1,4,5,8-tetra(n-but-
oxycarbonyl)naphthalene in the presence of copper bronze
and perfluorooctyl iodide at high temperature was inacces-
sible. Introduction of a trifluoromethyl group to 1,4,5,8-
tetra(n-butoxycarbonyl)naphthalene with 14 or 15 as reac-
tant under previous conditions35 also failed.
perfluorooctylation of PDIs under the above conditions
occurs very slowly. Compounds 4 and 40 can also be synthe-
sized in 50% and 9% yield, respectively, by the coupling
reaction of a mixture of 2 and 20 with perfluorooctyl iodide.
Hydrolysis of 3, 4, and 40 in chlorosulfonic acid was carried
out smoothly at room temperature, and resulted in 100%
yield of the corresponding 1-perfluorooctylperylene dianhy-
dride (5), 1,7-bis(perfluorooctyl)perylene dianhydride (6),
and 1,6-bis(perfluorooctyl)perylene dianhydride (60). The
products can be easily obtained just by adding the reaction
mixture to ice and filtering.
The condensation of 5, 6, and 60 with primary amines
in propanoic acid at reflux satisfactorily led to 7b (97%), 7c
(96%), 7e (97%), 8a (90%), 8b (96%), 8c (92%), 8e (99%), 8f
(91%), 8g (99%), and 80e (95%). One should notice that
the intermediates 5, 6, and 60 can condense with many other
amines to produce PDIs containing different functional side
chains on the imide nitrogen atoms, so they are valuable
platforms.
A mixture of 1,7-bis(trifluoromethyl)perylene dianhy-
dride and 1,6-bis(trifluoromethyl)perylene dianhydride (10
and 100, in a ratio of 10:1) was synthesized according to our
published work.35 The condensation of a mixture of 10 and
100 with primary amines in propanoic acid at 100 °C led to
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SCHEME 4. Synthesis of Perfluorooctylated Naphthalene Diimides
Hydrolysis of 16 and 17 in a tert-butyl alcohol-water
mixed solvent (10:1, v/v) solution of KOH at reflux led to 2-
perfluorooctylnaphthalene dianhydride (18) and 2,6-bis(per-
fluorooctyl)naphthalene dianhydride (19) as a white solid in
92% and 86% yield, respectively. But hydrolysis in chlorosul-
fonic acid at room temperature cannot lead to pure 18 or 19.
The condensation of 18 and 19 with primary amines in
propanoic acid at reflux led to 20a (92%), 20b (87%), 20c
(92%), 20d (82%), 21a (86%), 21b (82%), 21c (89%), and
21d (80%). Intermediates 18 and 19 can also condense with
many other amines to produce NDIs containing different
functional side chains on the imide nitrogen atoms, so they
are also valuable intermediates.
Due to poor solubility, intermediates 18 and 19 were only
characterized by HRMS, target compound 8g was charac-
terized by 1H NMR and HRMS, target compound 21a was
characterized by 1H-19F NMR and HRMS, and target
compound 21c was characterized by 1H-13C NMR and
HRMS. The other 25 new compounds containing fluorine
in this study were all well characterized by 1H-19F 13C NMR
and HRMS, and the intermediate 14 and 15 without fluorine
were well characterized by 1H-13C NMR and HRMS.
Solubility. Common PDIs have poor solubility in organic
solvents due to π-π stacking. For example, N,N0-bis(isooctyl)-
PDIs show very poor solubility in common organic solvents
(solubility less than 1 mg/mL in CH2Cl2). For another example,
Deyama et al. investigated the solubility of several kinds of
PDIs containing perfluoroalkyl groups and found cis-N,N0-
bis[2-(1H,1H-perfluoroheptyl)phenyl]-PDIs have the maxi-
mum solubility of 14 mg/mL in chloroform.36 In a review,
Langhals summarized the solubility of PDIs with two un-
branched alkyl groups attached to nitrogen atoms and con-
cluded that the solubility of those compounds is lower than
0.1 mg/mL in CHCl3. Poor solubility restricts their potential
applications as solution processable semiconductors, laser dyes
in liquid solution, and soluble fluorescent dyes and so on.
Interestingly, the solubility of perfluorooctyl-substituted PDIs
can be adjusted conveniently by changing the size of the groups
attached to nitrogen atoms. Taking 1,7-bis(perfluorooctyl)-
substituted PDIs for example, 8e or 8f with two isooctyl or
dodecyl groups attached to nitrogen atoms exhibits excellent
solubility (over 200 mg/mL in CH2Cl2) in common solvents
such as toluene, CH2Cl2, n-hexane, THF, etc. The solubility of
8a with two methyl groups is only about 2 mg/mL in CH2Cl2
and it is slightly soluble in THF and insoluble in n-hexane. The
solubility of 8c with two phenyl groups is about 6 mg/mL in
CH2Cl2. Compound 8g with no alkyl group is insoluble in
common organic solvents and only slightly soluble in trifluoro-
acetic acid. The solubility of 1-perfluorooctyl-PDIs has a
similar rule. For example, the solubility of 7b with two butyl
groups is about 10 mg/mL in CH2Cl2, while 7e with two octyl
groups shows a solubility of about 50 mg/mL in CH2Cl2. 1,6-
Bis(perfluorooctyl)-PDIs 80e as well as the two mixtures of
bis(trifluoromethyl)-PDIs (11b and 110b, 11d and 110d) have
good solubility in common solvents such as toluene, CH2Cl2,
and THF. The mixture of 11d and 110d (in CH2Cl2) shows
much better solubility than 11b and 110b (120 mg/mL for the
former, 8 mg/mL for the latter, in CH2Cl2).
Compounds 20a, 21a, 20c, and 21c with two methyl or
phenyl groups attached to nitrogen atoms of core-perfluor-
ooctylated NDIs exhibit poor solubility in common solvents
(about 1.3, 3.2, 2.4, and 1.8 mg/mL for the four compounds,
respectively, in CH2Cl2). 2-Perfluorooctyl-NDIs 20b and 20d
with two butyl or octyl groups show good solubility in
common solvents (about 30 mg/mL for 20b and 160 mg/mL
for 20d, in CH2Cl2), while 2,6-bis(perfluorooctyl)-NDIs 21b
and 21d show much poorer solubility (lower than 8 mg/mL for
20b and lower than 12 mg/mL for 20d, in CH2Cl2).
In a word, the solubility of core-perfluoroalkylated PDIs or
NDIs can be adjusted conveniently by changing the size of the
alkyl groups attached to nitrogen atoms. Core-perfluoroalky-
lated 8e, 8f, 80e, mixture of 11d and 110d, 20b, and 20d with
excellent solubility in common organic solvents are competi-
tive as candidates for solution processable semiconductor.
Electrochemistry. The electrochemical properties of 7b, 7c,
7e, 8b, 8c, 8e, 80e, 20a-d, 21a, 21b, mixture of 11b and 110b,
(36) Deyama, K.; Tomoda, H.; Muramatsu, H.; Matsui, M. Dyes Pigm.
1996, 30, 73–78.
(37) Thompson, B. C.; Kim, Y. G.; McCarley, T. D.; Reynolds, J. R.
J. Am. Chem. Soc. 2006, 128, 12714–12725.
J. Org. Chem. Vol. 75, No. 9, 2010 3011

Yuan et al.
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TABLE 1. Half-Wave Reduction Potentials (in V vs Fc/Fcþ) and LUMO
Energy of 7b, 7c, 7e, 8b, 8c, 8e, 80e, 11b, 11d, RPDIs, 20a-d, 21a, and 21b
E
E
exptl
LUMO (eV)b
theoretical
LUMO (eV)c
(M/M-1 a
)
(M-1/M-2 a
)
7b
7c
-0.98
-0.89
-0.92
-0.82
-0.75
-0.81
-0.82
-0.84
-0.80
-1.09
-0.90
-1.04
-0.91
-1.00
-0.74
-0.83
-1.22
-1.13
-1.15
-1.09
-1.03
-1.08
-1.12
-1.11
-1.05
-1.29
-1.51
-1.74
-1.51
-1.49
-1.41
-1.41
4.10
4.19
4.16
4.26
4.33
4.27
4.26
4.24
4.28
3.99
4.18
4.04
4.17
4.08
4.34
4.25
3.92
3.89
3.89
4.16
4.13
4.16
4.19
4.11
4.11
3.62
4.08
4.03
4.00
4.00
4.46
4.35
7e
8bd
8c
8e
80e
11be
11df
RPDIs
20a
20b
20c
20d
21a
21b
FIGURE 3. Reductive cyclic voltammograms of 7e, 8c, 80e, mixture
of 11b and110b, 20d, and 21b in CH2Cl2 (vs Ag/AgCl).
aMeasured in 0.05 M solution of Bu4NPF6 in CH2Cl2 with a scan rate
of 100 mV/s. bOn the basis of the assumption that the energy of Fc/Fcþ is
5.08 eV relative to vacuum.37 cDFT method, Gaussian 03 programs.
dThe two reduction potentials of N,N0-bis(butyl)-1,7-bis(perfluoro-
butyl) PDIs are -0.72 and -0.98 V, respectively, in ref 32. eMixture of
11b and 110b. fMixture of 11d and 110d.
TABLE 2. Optical Data of 7c, 7e, 8b, 8c, 8e, 80e, Mixture of 11b and
110b, Mixture of 11d and 110d, 20b-d, 21a, 21b, RPDIs, and RNDIs in
CH2Cl2
λ
abs (nm) ε (M-1 cm-1 em (nm) Sa (nm) jfl/λexb (nm)
) λ
7c
7e
8b
8c
8e
80e
519
518
508
509
508
509
506
506
524
384
383
384
387
388
382
47500
48700
53100
57400
49800
39200
60700
73600
89800
13500
21200
13900
15900
12500
14500
542
540
527
529
526
535
521
524
533
23
22
19
20
19
26
15
18
9
0.92/485
0.73/485
1.0/475
0.81/475
0.97/475
0.67/477
0.97/473
0.92/474
1.0/447
mixture of 11d and 110d, and reference compound N,N0-
bis(isooctyl)perylene diimides (RPDIs) were investigated by
cyclovoltammetry, and their reduction potentials, experi-
mental LUMO (E-LUMO) energy, and theoretical LUMO
(T-LUMO) energy are shown in Table 1. All the above
compounds show two reversible reduction peaks, indicating
they can accept two electrons, whereas within the accessible
scanning range in CH2Cl2 no oxidation waves can be de-
tected. Figure 3 shows reductive cyclic voltammograms of
7e, 8c, 80e, mixture of 11b and 110b, 20d, and 21b. For core-
perfluoroalkylated PDIs, both the first and the second reduc-
tion waves are at higher potentials than those of RPDIs,
indicating that the perfluoroalkyl-substituted PDIs receive
electrons more easily. The E-LUMO energy of 1-perfluoro-
octyl-PDIs (7b, 7c, and 7e, 4.10-4.19 eV) is 0.11-0.20 V
lower than that of RPDIs (3.99eV), and the LUMOenergy of
1,7-bis(perfluorooctyl)-PDIs (8b, 8c, and 8e, 4.26-4.33 eV),
1,6-bis(perfluorooctyl)-PDIs (80e, 4.26 eV), and bis(trifluoro-
methyl)-PDIs (mixture of 11b and 110b and mixture of 11d
and 110d, 4.24-4.28 eV) is 0.27-0.34 eV lower than that
of RPDIs, which indicates obviously stronger electron ac-
cepting ability of core-perfluoroalkylated PDIs relative to
unsubstituted PDIs and stronger electron accepting ability
of bis(perfluorooctyl)-PDIs (8b, 8c, 8e, and 80e) relative to
1-perfluorooctyl-PDIs (7b, 7c, and 7e). 1,6-Bis(perfluorooctyl)-
PDIs (80e) with E-LUMO energy of 4.26 eV is similar to those
of 1,7-bis(perfluorooctyl)-PDIs (8b, 8c, and 8e, 4.26-4.33 eV).
For core-perfluorooctylated NDIs, the E-LUMO energy of
two perfluorooctyl groups substituted NDIs (21a, 21b, 4.25-
4.34 eV) is 0.07-0.30 eV lower than that of one perfluorooctyl
group substituted NDIs (20a-d, 4.04-4.18 eV).
11bc
11dd
RPDIs
20b
20c
20d
21a
21b
RNDIse
aStokes shifts. bDetermined with rhodamine 6G as reference.40
cMixture of 11b and 110b. Mixture of 11d and 110d. eThe data of
d
RNDIs (N,N0-bis(octyl)naphthalene diimides) is from the literature.41
FIGURE 4. UV-vis absorption (left) and fluorescence emission
(right) spectrum of 7e, 8e, 80e, and RPDIs in CH2Cl2.
That is, electron-withdrawing perfluoroalkyl groups can
effectively lower the LUMO energy of PDIs and the more
electron-withdrawing groups the lower the LUMO energy,
which is consistent with the trend for E-LUMOs. The above
trend also exists in the NDIs series; for example, T-LUMOs
of 2,6-bis(perfluorooctyl)-NDIs are 0.32-0.46 eV lower
than those of 2-perfluorooctyl-NDIs, and the trend is con-
sistent with that of E-LUMOs. The HOMO energy and
HOMO and LUMO electron density for all compounds in
Table 1 were also calculated, and the results are given in the
Supporting Information.
For 80e, 20b, and 20d, T-LUMO energy is very close to
E-LUMO energy (lower than 0.1 eV difference), and for the
other compounds the difference between T-LUMO energy
and E-LUMO energy is in the range of 0.1-0.3 eV. A clear
trend for T-LUMO energy is that T-LUMOs of 1-perfluoro-
octyl-PDIs and 1,7-bis(perfluoroalkyl)-PDIs are 0.27-0.3
and 0.49-0.57 eV lower than that of RPDIs, respectively.
3012 J. Org. Chem. Vol. 75, No. 9, 2010

Yuan et al.
JOCArticle
FIGURE 5. UV-vis absorption (left) and fluorescence emission (right) spectrum for a mixture of 11b and 110b, a mixture of 11d and 110d,
and RPDIs in CH2Cl2.
All these compounds with E-LUMO energy between 4.04
and 4.34 eV demonstrate strong electron-accepting ability,
and their E-LUMO energy is similar to that of extensively
used and expensive n-type semiconductor PCBM (4.2 eV),
which makes these core-perfluoroalkylated PDIs or NDIs
potential substitutes for PCBM.
Optical Properties. Compound 7c, 7e, 8b, 8c, 8e, 80e,
mixture of 11b and 110b, mixture of 11d and 110d, 20b-d,
21a, 21b, RPDIs, and N,N0-bis(octyl)naphthalene diimides
(RNDIs) were selected as representative samples in an
optical test, and their optical data was listed in Table 2.
Figure 4 shows absorption and fluorescence emission of 7e,
8e, 80e, and RPDIs in CH2Cl2. Figure 5 shows absorption
and fluorescence emission for a mixture of 11b and 110b, a
mixture of 11d and 110d, and RPDIs in CH2Cl2. Figure 6
shows the absorption of 20b, 20c, 21a, and 21b in CH2Cl2.
As shown in Figure 4, the maximum absorptions of core-
perfluorooctylated PDIs 7e, 8e, and 80e (located at 518, 508,
and 509 nm) display blue shifts of 6, 16, and 15 nm, res-
pectively, relativetothat of unsubstituted RPDIs. Meanwhile,
their maximum molar extinction coefficients (48 700, 49800,
and 39 200, respectively) decrease remarkably relative to that
of RPDIs (89 800). A twist of the perylene core exists in many
previous core-substituted perylene biimides.33,38 And it is
likely that the twist also exists in the above perfluorooctyl-
substituted molecules, which partly causes the blue shifts and
decreased extinction coefficients.
As shown in Figure 5, similar to those of core-perfluoro-
octylated PDIs, the maximum absorptions of core-trifluoro-
methylated PDIs (mixture of 11b and 110b and mixture of
11d and 110d, located at 506 nm) display blue shifts of 18 nm
relative to that of RPDIs. And their maximum molar extinc-
tion coefficients (11b: 60 700; 11d: 73 600) also decrease
obviously compared to that of RPDIs.
In this study, all the core-perfluoroalkylated PDIs inherit
the strong fluorescence from the PDIs family, and their
fluorescence quantum yields are higher than 0.67, which
makes them promising fluorescent dyes. Core-perfluor-
oalkylated PDIs possess bigger Stokes shifts (15-26 nm)
relative to that of RPDIs (9 nm), and this indicates their
stronger molecular vibration, which may be partly respon-
sible for a little lower fluorescence quantum yields of some
core-perfluoroalkylated PDIs. 1,6-Bis(perfluorooctyl)-PDIs
(80e) with Stoke shifts 26 nm and fluorescence quantum yield
0.67 is different from 1,7-bis(perfluorooctyl)-PDIs (8b, 8c,
FIGURE 6. UV-vis absorption of 20b, 20c, 21a, and 21b inCH2Cl2.
and 8e, with Stoke shifts 19-20 nm and fluorescence quan-
tum yield 0.81-1.0). Though 1,7-bis(perfluoroalkyl)-PDIs
were proved to be air-stable n-type organic semiconductors,
the properties of 1,6-bis(perfluoroalkyl)-PDIs have not been
studied. So it is worth investigating the applications of 1,6-
bis(perfluoroalkyl)-PDIs in electronic devices in the future.
As shown in Figure 6, in the range of 300-400 nm, one
perfluorooctyl group substituted NDIs (20b and 20c) exhi-
bits two absorption bands with nearly equal intensity, while
two perfluorooctyl groups substituted NDIs (21a and 21b)
show a strongest peak and another three strong peaks with
similar intensity. The different absorption profiles may be
attributed to different numbers of electron-withdrawing
substitutes.39 The maximum absorptions of 20b and 20c
(located at 384 and 383 nm) are almost the same as that of
RNDIs (located at 382 nm), and the maximum absorptions
of 21a and 21b (located at 387 and 388 nm) display a little
blue shift of 5 and 6 nm, respectively. The maximum
absorptions of NDIs are almost unaffected by introduction
of perfluorooctyl groups to their cores. In this study, the
fluorescence of core-perfluorooctylated NDIs and RNDIs is
very weak, so they were not investigated here.
Conclusions
A versatile synthesis of core-perfluoroalkylated perylene
diimides (PDIs) and naphthalene diimides (NDIs) was
developed, and PDIs perfluoroalkylated at 1-position or
1,6-positions and core-perfluoroalkylated NDIs were first
(39) Wurthner, F.; Ahmed, S.; Thalacker, C.; Debaerdemaeker, T.
Chem.;Eur. J. 2002, 8, 4742–4750.
(40) Fischer, M.; Georges, J. Chem. Phys. Lett. 1996, 260, 115–118.
(41) Chopin, S.; Chaignon, F.; Blart, E.; Odobel, F. J. Mater. Chem. 2007,
17, 4139–4146.
(38) Wurthner, F.; Osswald, P.; Schmidt, R.; Kaiser, T. E.; Mansikkamaki,
H.; Konemann, M. Org. Lett. 2006, 8, 3765–3768.
J. Org. Chem. Vol. 75, No. 9, 2010 3013

Yuan et al.
JOCArticle
obtained. The perfluorooctyl group was introduced to
3,4,9,10-tetra(n-butoxycarbonyl)perylene directly in the pre-
sence of copper bronze as catalyst for the first time. 1-Per-
fluorooctyl-PDIs (7b, 7c, and 7e), 1,7-bis(perfluorooctyl)-
PDIs (8a-c and 8e-g), 1,6-bis(perfluorooctyl)-PDIs (80e), a
mixture of 1,7-bis(trifluoromethyl)-PDIs and 1,6-bis(trifluo-
romethyl)-PDIs (11b and 110b, 11d and 110d, in a ratio of
19:1), 2-perfluorooctyl-NDIs (20a-d), and 2,6-bis(perfluo-
rooctyl)-NDIs (21a-d) were efficiently synthesized. Five
valuable intermediates 5, 6, 60, 18, and 19 were also obtained,
and they can condense with many kinds of amines to produce
core-perfluoroalkylated PDIs or NDIs containing different
functional side chains on the imide nitrogen atoms. The
solubility of core-perfluoroalkylated PDIs or NDIs can be
adjusted conveniently by changing the size of groups attached
to the nitrogen atoms. Core-perfluoroalkylated 8e, 8f, 80e,
mixture of 11d and 110d, 20b, and 20d with excellent solubility
in common organic solvents are competitive as candidates for
solution processable semiconductor. Core-perfluoroalkylated
PDIs and NDIs with experimental LUMO energy 4.04-
4.34 eV demonstrate strong electron accepting ability, and
their experimental LUMO energy is similar to that of exten-
sively used and expensive n-type semiconductor PCBM
(4.2 eV), which makes them potential substitutes for PCBM.
For core-perfluoroalkylated PDIs, the maximum absorptions
display blue shifts of 6-18 nm relative to unsubstituted PDIs,
the maximum molar extinction coefficients decrease ob-
viously relative to unsubstituted PDIs, and they inherit the
strong fluorescence from PDIs family, which makes them
promising fluorescent dyes. The applications of these com-
pounds are in progress.
δ 13.9, 19.4, 29.9, 66.1, 122.6, 123.0, 127.7, 128.8, 129.1, 129.3,
129.6, 129.9, 130.1, 130.4, 130.5, 130.8, 130.9, 131.9, 132.0, 133.4,
136.9, 167.8, 168.8 ppm.
Synthesis of 4 and 40 According to Scheme 1. A mixture of the
mixture of 2 and 20 (750 mg, 0.93 mmol), perfluorooctyl iodide
(1 mL, 3.7 mmol), and copper bronze (430 mg, 6.7 mmol) was
stirred at 100 °C in 5 mL of DMSO for 16 h under argon. After
cooling to room temperature, the reaction was quenched by
addition of water and CH2Cl2, washed three times with water,
dried over MgSO4, and purified through silica gel column
chromatography.
Compound 4 was obtained as a slightly green solid (700 mg,
50%). Mp 159-161 °C; HRMS calcd for C56H42O8F34Na
1
1511.2234, found 1511.2178 ([M þ Na]þ, ESI); H NMR (400
MHz, CDCl3) δ 1.00 (m, 12H), 1.52 (m, 8H), 1.81 (m, 8H), 4.40
(m, 8H), 7.92 (m, 2H), 8.14 (d, 2H), 8.38 (s, 2H); 19F NMR
(376.5 MHz, CDCl3) δ -126.13, -122.69, -121.83, -121.58,
-121.06, -116.63, -97.47, -80.88 ppm; 13C NMR (100 MHz,
CDCl3) δ 13.7, 19.3, 30.6, 66.0, 118.4, 124.4, 127.6, 129.4, 130.2,
130.5, 130.6, 131.2, 131.4, 134.6, 167.4, 167.8 ppm.
Compound 40 was obtained as a yellow solid (125 mg, 9%).
Mp 167-168 °C; HRMS calcd for C56H42O8F34Na 1511.2167,
found 1511.2234([M þ Na]þ, ESI); 1H NMR(400 MHz, CDCl3)
δ 1.00 (m, 12H), 1.52 (m, 8H), 1.80 (m, 8H), 4.39 (m, 8H),
8.06 (m, 2H), 8.10 (d, 2H), 8.51 ppm (s, 2H); 19F NMR (376.5
MHz, CDCl3) δ -126.50, -123.08, -122.22, -121.97, -121.50,
-115.86, -97.35, -81.20 ppm; 13C NMR (100 MHz, CDCl3)
δ 13.9, 19.4, 30.7, 66.4, 66.5, 113.3, 125.4, 126.4, 129.0, 129.4,
130.8, 131.2, 132.2, 135.8, 167.4, 168.7 ppm.
Synthesis of 3, 4, and 40 According to Scheme 2. A mixture of 9
(1.5 g, 2.3 mmol), perfluorooctyl iodide (2.5 mL, 9.2 mmol), and
3 g of copper bronze was stirred at 190 °C in 7.5 mL of DMSO in
a sealed autoclave for 3 h. After cooling to room temperature,
the reaction was quenched by addition of water and CH2Cl2,
washed three times with water, dried over MgSO4, and purified
by silica gel column chromatography. Compounds 3 (0.55 g,
22%), 4 (0.44 g, 13%), and 40 (0.35 g, 10%) were obtained.
Synthesis of 5. Compound 3 (1 g, 0.93 mmol) was added to
5 mL of stirring chlorosulfonic acid gradually and the mixture
was stirred for 4 h at room temperature. Then the mixture was
added to ice. After filtration, compound 5 was obtained as a
brown solid (0.75 g, 100%). Mp >300 °C; HRMS calcd for
C32H7O6F17 809.9971, found 810.0010 (M-, MALDI-TOF); 1H
NMR (400 MHz, CF3COOD) δ 8.45 (m, 1H), 8.61 (d, 1H),
8.70 (m, 3H), 8.74 (d, 1H), 8.90 ppm (s, 1H); 19F NMR (376.5
MHz, CDCl3) δ -126.30, -122.88, -121.97, -121.69, -121.26,
-115.22, -97.88, -81.14 ppm; 13C NMR (100 MHz, CF3-
COOD) δ 119.6, 120.1, 120.2, 121.0, 125.6, 126.0, 126.2, 126.9,
127.3, 128.1, 129.7, 129.8, 129.9, 130.1, 131.8, 132.8, 133.6,
134.6, 135.0, 135.3, 135.4, 136.0, 136.4, 137.3, 138.2, 140.6 ppm.
Synthesis of 6. Compound 4 (1.8 g, 1.21 mmol) was added to
5 mL of stirring chlorosulfonic acid gradually and the mixture
was stirred for 4 h at room temperature. Then the mixture was
added to ice. After filtration, compound 6 was obtained as a
brown solid (1.47 g, 100%). Mp 269-270 °C; HRMS calcd for
C40H6O6F34 1227.9621, found 1227.9598 (M-, MALDI-TOF);
1H NMR (400 MHz, CF3COOD) δ 8.37 (m, 2H), 8.68 (d, 2H),
8.93 ppm (s, 2H); 19F NMR (376.5 MHz, CDCl3) δ -126.53,
-123.10, -122.21, -121.96, -121.46, -116.17, -98.2, -81.14
ppm; 13C NMR (100 MHz, CF3COOD) δ 119.9, 120.2, 129.7,
129.8, 131.3, 134.6, 134.8, 135.1, 135.2, 138.2 ppm.
Experimental Section
Compound 9 was synthesized by a literature method.42 Com-
pound 1 and the mixture of 2 and 20 were synthesized according to
our previous work.35,43 The other reactants were purchased from
commercial sources. NMR spectra were measured with use of
TMS as internal standard for 1H NMR and 13C NMR and with
CFCl3 as reference for 19F NMR. Cyclic voltammetry (CV) was
performed with a standard commercial electrochemical analyzer
in a three-electrode single-component cell under argon with a scan
rate of 100 mV/s. Working electrode: glassy carbon; reference
electrode: Ag/AgCl; auxiliary electrode: Pt disk; supporting elec-
trolyte: tetrabutylammonium hexafluorophosphate (Bu4NPF6);
internal standard: ferrocene (Fc).
There are two synthetic routes for 3, 4 and 40.
Synthesis of 3 According to Scheme 1. A mixture of 1 (150 mg,
0.20 mmol), perfluorooctyl iodide (200 μL, 0.75 mmol), and
copper bronze (66 mg, 1.0 mmol) was stirred at 100 °C in 1 mL
of DMSO for 16 h under argon. After cooling to room tempera-
ture, the reaction was quenched by addition of water and CH2Cl2,
washed three times with water, dried over MgSO4, and purified
through silica gel column chromatography. Compound 3 was
obtained as a viscous oil (49 mg, 23%). HRMS calcd for C48H43-
O8F17Na 1093.2584, found 1093.2538 ([M þ Na]þ, ESI); 1H
NMR (400 MHz, CDCl3) δ 1.00 (m, 12H), 1.49 (m, 8H), 1.79
(m, 8H), 4.36 (m, 8H), 7.94 (d, 1H), 8.03 (d, 1H), 8.16 (d, 1H), 8.21
(d, 1H), 8.33 (m, 2H), 8.40 ppm (s, 1H); 19F NMR (376.5 MHz,
CDCl3) δ -126.08, -122.65, -121.78, -121.55, -121.06,
-115.63, -97.35, -80.75 ppm; 13C NMR (100 MHz, CDCl3)
Synthesis of 60. Compound 40 (400 mg, 0.27 mmol) was added
to 5 mL of stirring chlorosulfonic acid gradually and the mixture
was stirred for 4 h at room temperature. Then the mixture was
added to ice. After filtration, compound 60 was obtained as a
brown solid (330 mg, 100%). Mp 275-276 °C; HRMS calcd for
C40H6O6F34 1227.9621, found 1227.9637 (M-, MALDI-TOF);
1H NMR (400 MHz, CF3COOD) δ 8.45 (m, 2H), 8.63 (d, 2H),
(42) Mo, X.; Chen, H. Z.; Shi, M. M.; Wang, M. Chem. Phys. Lett. 2006,
417, 457–460.
(43) Yuan, Z.; Xiao, Y.; Qian, X. Chem. Commun. 2010. DOI: 10.1039/
b925605a.
3014 J. Org. Chem. Vol. 75, No. 9, 2010

Yuan et al.
JOCArticle
8.96 ppm (s, 2H); 19F NMR (376.5 MHz, CDCl3) δ -126.47,
-123.03, -122.12, -121.87, -121.48, -115.32, -98.92, -81.10
ppm; 13C NMR (100 MHz, CF3COOD) δ 122.0, 128.7, 131.1,
131.4, 132.3, 134.0, 134.7, 140.6 ppm.
Synthesis of 14 and 15. A mixture of KOH (1.4 g, 25 mmol),
200 mL of water, and a mixture of 12 and 13 (2.13 g) was stirred
at room temperature for about 0.5 h, and then 1-bromobutane
(5 mL, 46 mmol) and tetraoctyl ammonium bromide (2 g) were
added to the reaction mixture. The reaction continued at reflux
for another 3 h. After purification through silica gel chroma-
tography (with a mixture of CH2Cl2 and petroleum ether as
eluent), compounds 14 and 15 was obtained as a light yellow and
viscous liquid.
primary amine was stirred in propanoic acid at 100 °C or at the
boiling point of the solvent for 2-3 h. After cooling to room
temperature, precipitations were filtered for 8a and 8g. After
adding water to the reaction mixture, precipitations were also
filtered for the other target compounds. For 8g, a filter cake was
pure enough to be characterized by 1H NMR was obtained. The
other compounds were purified by silica gel column chroma-
tography with CH2Cl2 as eluent. Only the synthesis of com-
pounds 7b, 8a, 80a, mixture of 11b and 110b, 20c, and 21d are
listed here, and detailed syntheses of the other compounds are
given in the Supporting Information.
7b: Compound 5 (0.26 g, 0.32 mmol), n-butylamine (0.5 mL,
5.0 mmol), and 12 mL of propanoic acid led to 7b as a red solid
(0.29 g, 0.31 mmol, 97%). Mp 245-247 °C; HRMS calcd for
C40H26N2O4F17 921.1621, found 921.1653 (Mþ, MALDI-TOF);
1H NMR (400 MHz, CDCl3) δ 1.00 (m, 6H), 1.49 (m, 4H), 1.76
(m, 4H), 4.23 (m, 4H), 8.33 (m, 1H), 8.64 (m, 3H), 8.75 (d, 1H),
8.80 (d, 1H), 8.92 ppm (s, 1H); 19F NMR (376.5 MHz, CDCl3)
δ -126.07, -122.62, -121.71, -121.47, -121.09, -114.76,
-97.48, -80.71 ppm; 13C NMR (100 MHz, CDCl3) δ 13.8,
20.4, 30.2, 40.5, 122.6, 122.9, 123.8, 123.9, 124.1, 124.6, 126.7,
128.3, 128.4, 129.4, 130.1, 131.0, 131.7, 132.1, 132.2, 132.5, 133.1,
135.2, 137.7, 162.6, 163.1, 163.2, 163.4 ppm.
8a: Compound 6 (0.24 g, 0.20 mmol), 30% aqueous methy-
lamine (0.5 mL, 4.8 mmol), and 15 mL of propanoic acid led to
8a as a red solid (0.23 g, 0.18 mmol, 90%). Mp: 218-221 °C;
HRMS calcd for C42H12N2O4F34 1254.0254, found 1254.0139
(Mþ, MALDI-TOF); 1H NMR (400 MHz, CDCl3) δ 6.25
(s, 6H), 8.31 (m, 2H), 8.76 (d, 2H), 9.00 ppm (s, 2H); 19F
NMR (376.5 MHz, CDCl3) δ -126.13, -122.67, -121.80,
-121.56, -121.10, -115.81, -98.14, -80.71 ppm; 13C NMR
(100 MHz, CDCl3) δ 27.4, 123.1, 123.6, 126.8, 127.9, 128.3,
131.0, 131.3, 132.4, 132.5, 135.5, 162.7, 163.0 ppm.
80e: Compound 60 (0.20 g, 0.16 mmol), isooctylamine (0.5 mL,
3.0 mmol), and 10 mL of propanoic acid led to 80e as a brown
solid (0.22 g, 95%). Mp 128-131 °C; HRMS calcd for
C56H40N2O4F34 1450.2445, found 1450.2540 (Mþ, MALDI-
TOF); 1H NMR (400 MHz, CDCl3) δ 0.85-1.00 (m, 12H),
1.20-1.60 (m, 16H), 2.01 (m, 2H), 4.17 (m, 4H), 8.40 (d, 2H),
8.70 (d, 2H), 9.02 (d, 2H); 19F NMR (376.5 MHz, CDCl3)
δ -126.07, -122.61, -121.72, -121.49, -121.11, -114.82,
-98.34, -80.69 ppm; 13C NMR (100 MHz, CDCl3) δ 10.8,
14.3, 23.3, 24.2, 28.9, 29.9, 30.9, 37.6, 44.7, 45.0, 122.4, 125.0,
126.6, 127.0, 127.6, 129.5, 129.8, 130.1, 130.2, 131.8, 133.0,
137.3, 162.7, 163.7 ppm.
Mixture of 11b and 110b: A mixture of 10 and 100 (300 mg,
0.57 mmol), n-butylamine (831 mg, 11.4 mmol), and 15 mL of
propanoic acid led to a mixture of 11b and 100b as a red solid
(231 mg, 64%). Mp 282-283 °C; HRMS calcd for C34H24N2-
O4F6 638.1640, found 638.1636 (Mþ, MALDI-TOF); 1H NMR
(400 MHz, CDCl3) δ 0.99 (m, 6H), 1.51 (m, 4H), 1.75 (m, 4H),
4.25 (t, 4H), 8.56 (d, 2H), 8.79 (d, 2H), 9.06 ppm (s, 2H); 19F
NMR (376.5 MHz, CDCl3) δ -55.81 ppm; 13C NMR (100
MHz, CDCl3) δ 14.0, 20.5, 30.4, 40.9, 123.5, 123.9, 128.0, 128.7,
130.3, 132.0, 132.8, 134.0, 162.7, 162.9 ppm. Only NMR signals
of the main regioisomer 11b were given.
20c: Compound 18 (200 mg, 0.29 mmol), aniline (135 mg,
1.45 mmol), and 1 mL of propanoic acid led to 20c as a white
solid (223 mg, 92%). Mp >300 °C; HRMS calcd for C34H13-
N2O4F17 836.0604, found 836.0536 (Mþ, MALDI-TOF); 1H
NMR (400 MHz, CDCl3) δ 7.33 (m, 4H), 7.55 (m, 6H), 8.95
(s, 2H), 9.07 ppm (s, 1H); 19F NMR (376.5 MHz, CDCl3)
δ -126.31, -122.88, -122.03, -121.61, -121.47, -115.38,
-98.77, -81.24 ppm; 13C NMR (100 MHz, CDCl3) δ 126.9,
127.0, 127.8, 128.3, 128.4, 128.5, 129.3, 129.5, 129.7, 131.0,
132.7, 133.3, 134.1, 134.5, 159.9, 161.9, 162.3 ppm.
14 (1 g, a29% overall yield for bromination and esterification):
HRMS calcd for C30H39O8NaBr 629.1726, found 629.1710
([M þ Na]þ, ESI); 1H NMR (400 MHz, CDCl3) δ 0.98 (m, 12H),
1.49 (m, 8H), 1.73 (m, 8H), 4.31 (m, 8H), 7.87 (d, 1H), 8.01 (d,
1H), 8.19(s, 1H); 13C NMR(100MHz, CDCl3) δ 13.7, 19.2, 19.3,
30.3, 30.5, 65.7, 65.9, 66.0, 66.1, 121.2, 127.7, 128.9, 129.0, 129.7,
133.1, 133.3, 133.5, 134.2, 134.4, 166.7, 166.8, 167.6, 167.8 ppm.
15 (0.96 g, 24% overall yield for bromination and esterifi-
cation): HRMS calcd for C30H38O8NaBr2 707.0831, found
1
707.0846 ([M þ Na]þ, ESI); H NMR (400 MHz, CDCl3) δ
0.97 (m, 12H), 1.48 (m, 8H), 1.78 (m, 8H), 4.31 (t, 8H), 8.05
(d, 2H); 13C NMR (100 MHz, CDCl3) δ 13.7, 19.2, 19.3, 30.3,
30.4, 66.2, 121.2, 128.5, 132.8, 134.4, 134.5, 166.4, 166.5 ppm.
Synthesis of 16. A mixture of 14 (1.07 g, 1.76 mmol), per-
fluorooctyl iodide (1.1 mL, 4 mmol), and copper bronze
(520 mg, 8.13 mmol) was stirred at 80 °C in 2 mL of DMSO
for 7 h under argon. After purification through silica gel column
chromatography, compound 16 was obtained as a light yellow
and viscous oil (1.09 g, 66%). HRMS calcd for C38H39O8F17Na
969.2271, found 969.2238 ([M þ Na]þ, ESI); 1H NMR (400
MHz, CDCl3) δ 0.95 (m, 12H), 1.46 (m, 8H), 1.77 (m, 8H), 4.30
(m, 8H), 7.85 (d, 1H), 8.12-8.15 (m, 2H); 19F NMR (376.5
MHz, CDCl3) δ -126.08, -122.66, -121.87, -121.69, -121.43,
-177.91, -103.75, -80.74 ppm; 13C NMR (100 MHz, CDCl3) δ
13.8, 14.3, 19.1, 19.3, 22.9, 19.6, 29.9, 30.6, 32.1, 66.0, 66.2, 66.3,
67.0, 127.8, 128.4, 129.2, 130.3, 130.9, 133.0, 133.2, 135.0, 135.6,
166.7, 167.1, 167.5, 167.9 ppm.
Synthesis of 17. A mixture of 15 (0.66 g, 0.97 mmol), per-
fluorooctyl iodide (1.0 mL, 3.63 mmol), and copper bronze
(750 mg, 11.7 mmol) was stirred at 80 °C in 2 mL of DMSO for
7 h under argon. After purification through silica gel column
chromatography, compound 17 was yielded as a white solid
(0.8 g, 61%). Mp 137-138 °C; HRMS calcd for C46H38O8F34Na
1387.1921, found 1387.1970 ([M þ Na]þ, ESI); 1H NMR (400
MHz, CDCl3) δ 0.95 (m, 12H), 1.46 (m, 8H), 1.77 (m, 8H), 4.25
(t, 4H), 4.33 (t, 4H), 7.98 (s, 1H); 19F NMR (376.5 MHz, CDCl3)
δ -126.07, -122.64, -121.85, -121.65, -121.39, -177.82,
-103.97, -80.73 ppm; 13C NMR (100 MHz, CDCl3) δ 13.6,
19.0, 19.1, 29.7, 30.3, 66.6, 67.1, 127.3, 127.7, 129.6, 134.5, 134.6,
165.8, 166.6 ppm.
Synthesis of 18. A mixture of 16 (430 mg, 0.45 mmol), KOH
(500 mg, 8.9 mmol), 0.5 mL of water, and 0.5 mL of tert-butyl
alcohol was refluxed for 12 h. After washing with water,
compound 18 was obtained as a white solid (286 mg, 92%).
Mp 135-138 °C; HRMS calcd for C22H3O6F17 685.9658, found
685.9640 (M-, MALDI-TOF).
Synthesis of 19. A mixture of 17 (200 mg, 0.15 mmol), KOH
(500 mg, 8.9 mmol), 0.5 mL of water, and 0.5 mL of teert-butyl
alcohol was refluxed for 12 h. After washing with water,
compound 19 was obtained as a white solid (140 mg, 86%).
Mp >300 °C; HRMS calcd for C30H2O6F34 1103.9308, found
1103.9268 (M-, MALDI-TOF).
General Procedure for the Synthesis of 7b, 7c, 7e, 8a-c, 8e-g,
80e, Mixture of 11b and 110b, Mixture of 11d and 110d, 20a-d, and
21a-d. A mixture of 5, 6, 60, mixture of 10 and 100, 18, or 19 and
21d: Compound 19 (200 mg, 0.18 mmol), n-octylamine
(115 mg, 0.9 mmol), and 1 mL of propanoic acid led to 21d
J. Org. Chem. Vol. 75, No. 9, 2010 3015

Yuan et al.
JOCArticle
as a white solid (190 mg, 80%). Mp 129-131 °C; HRMS
calcd for C46H316N2O4F34 1326.2132, found 1326.2172 (M-,
MALDI-TOF); H NMR (400 MHz, CDCl3) δ 0.87 (m, 6H),
1.27-1.41 (m, 20H), 1.74 (m, 4H), 4.10 (m, 4H), 9.10 ppm
(s, 2H); 19F NMR (376.5 MHz, CDCl3) δ -126.00, -122.57,
-121.73, -121.33, -114.81, -98.73, -80.71 ppm; 13C NMR
(100 MHz, CDCl3) δ 14.0, 22.6, 27.0, 27.9, 29.2, 29.7, 31.8, 41.7,
127.3, 127.7, 128.9, 131.4, 131.5, 134.9, 159.3, 160.7 ppm.
for Changjiang Scholars and Innovative Research Team in
University (IRT0711) for financial support.
Supporting Information Available: HPLC spectrum of 15;
detailed synthesis of 7c, 7e, 8b, 8c, 8e, 8f, 8g, mixture of 11d and
110d, 20a, 20b, 20d, and 21a-c; cyclovoltammograms of 7b, 7c, 8b,
8e, mixture of 11d and 110d, 20a-c, and 21a; HOMO and LUMO
electron density and theoretical HOMO energy of 7b, 7c, 7e, 8b,
8c, 8e, 11b, 11d, RPDIs,20a-d, 21a, and21b; absorption and fluo-
rescence emission spectrum of 7c, 8b, and 8c; absorption spectrum
of 20d; and copies of NMR spectra. This material is available free
of charge via the Internet at http://pubs.acs.org.
Acknowledgment. The authors thank National Natural
Science Foundation of China (No. 20876022) and the Program
3016 J. Org. Chem. Vol. 75, No. 9, 2010