Synthesis of water-soluble perylenediimide-functionalized polymer through esterification with poly(vinyl alcohol)

Article abstract of DOI:10.1002/pola.24142

A new material has been prepared by covalent attachment of a perylene derivative, W-(carboxyphenyl)-N'-(8pentadecyl)perylene-3,4:9,10- bis(dicarboximide) (PDI-COOH), to poly(vinyl alcohol) (PVA) by esterification. The perylenediimide (PDI)-modified PVA po

Full text of DOI:10.1002/pola.24142

Synthesis of Water-Soluble Perylenediimide-Functionalized Polymer
Through Esterification with Poly(vinyl alcohol)
1
2
2
HORACIO J. SALAVAGIONE,1 GERARDO MARTINEZ, RAFAEL GOMEZ, JOSE L. SEGURA
´
´
´
1Instituto de Ciencia y Tecnolog´ıa de Polı´meros, CSIC, Juan de la Cierva 3, 28006 Madrid, Spain
2Departamento de Qu´ımica Orga´nica, Facultad de Qu´ımica, Universidad Complutense de Madrid, 28040 Madrid, Spain
Received 5 April 2010; accepted 20 May 2010
DOI: 10.1002/pola.24142
Published online in Wiley InterScience (www.interscience.wiley.com).
ABSTRACT: A new material has been prepared by covalent
attachment of a perylene derivative, N-(carboxyphenyl)-N0-(8-
pentadecyl)perylene-3,4:9,10-bis(dicarboximide) (PDI-COOH), to
poly(vinyl alcohol) (PVA) by esterification. The perylenediimide
(PDI)-modified PVA polymers are soluble in water and dime-
thylsulfoxide (DMSO). This solubility is conferred to the insolu-
ble perylene derivative by the water-soluble polymer. The
materials have been characterized by hydrogen-nuclear mag-
netic resonance, Fourier transform infrared spectra, X-ray dif-
fraction, and X-ray photoelectron spectroscopy confirming the
covalent attachment of the PDI to the polymer chains. The sig-
nificant changes in the crystalline parameters and the thermal
stability observed for the polymer after the esterification also
confirm the covalent linkage with PDI. In addition, the PDI-
modified PVA shows good fluorescence both in solution (quan-
tum yield ꢀ0.2–0.25) and in solid suggesting that the PDI
retains largely its photochemical and photophysical properties
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after immobilization. 2010 Wiley Periodicals, Inc. J Polym Sci
Part A: Polym Chem 48: 3613–3622, 2010
KEYWORDS: esterification; fluorescence; perylenediimide; PVA;
water solubility
INTRODUCTION Perylene tetracarboxylic acid bisimide, in
short perylenediimide (PDI)-based colorants have received a
great deal of attention not only in academic but also as
industrial dye and in pigment research.1 More recently, PDI
derivatives have developed into one of the best n-type semi-
conductors available to date2 and have found application in
different areas such as organic solar cells,3 fluorescent
labels,4 sensors,5 lasers,6 sensitizers for photodynamic ther-
apy,7 field effect transistors,8 or color tunable light-emitting
diodes.9 In parallel with the different applications found for
PDI derivatives, a broad range of derivatives have been syn-
thesized including multi-PDI derivatives,10 supramolecular
architectures,11–12 derivatives with extended p-conjugation,13
and a number of PDI derivatives covalently linked to electro-
active moieties such as ferrocene,14 anthraquinone,15 and
[60]fullerene16 among others. Additionally, a number of con-
jugated oligomers and polymers have been linked to the PDI
moiety through covalent or supramolecular bonds for elec-
trochemical and photophysical studies mainly focused on the
investigation of their photoinduced energy and/or electron
transfer processes.17–19
sometimes their applications.20 It its known that perylene
modified with carboxylic acids are versatile and very reactive
compounds that can accept a wide number of functionalities,
being 3,4:9,10-perylene tetracarboxylic acid, the most
employed. Thus, several synthetic strategies21–23 have been
used to prepare water-soluble21 and organo-soluble22,23 PDI
dyes. As PDI dyes have high quantum yield of fluorescence, the
preparation of water-soluble PDIs makes them ideal as high-
performance fluorescent labels for biologically active probes.
Considering their excellent thermal and photo stabilities,
their electron acceptor and photoconductive properties, the
syntheses of soluble, processable, and thermally stable poly-
mers containing PDI moieties is highly desirable for different
photonic and optoelectronic applications. With this aim,
attempts to incorporate PDI derivatives into polymers have
been already carried out. Although the direct incorporation
of dyes into an appropriate soluble polymer is difficult
because of the low reactivity and solubility of the aromatic
blocks used as monomers, different strategies have been fol-
lowed to incorporate PDI moieties into polymer chains either
as side chains or as part of the main chain.
A very well-known characteristic of aromatic polyimides is their
poor solubility in organic solvents, especially those derived
from rigid anhydrides such as PDI. This property makes them
generally intractable or difficult to process, thus restricting
In 1994, Ghassemi and Hay24 reported a seminal paper
describing the synthesis of red pigmentary polyimides made
by polymerization of N,N0-diamino-3,4,9,10-perylenetetracar-
boxylic acid diimide with suitable bisanyhydrides. Other
Additional Supporting Information may be found in the online version of this article. Correspondence to: H. J. Salavagione (E-mail: horacio@ictp.
csic.es) or J. L. Segura (E-mail: segura@quim.ucm.es)
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Journal of Polymer Science: Part A: Polymer Chemistry, Vol. 48, 3613–3622 (2010) 2010 Wiley Periodicals, Inc.
SYNTHESIS OF WATER-SOLUBLE PDI-FUNCTIONALIZED POLYMER, SALAVAGIONE ET AL.
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JOURNAL OF POLYMER SCIENCE: PART A: POLYMER CHEMISTRY DOI 10.1002/POLA
SCHEME 1 Chemical structure of the PDI-COOH employed in the esterification reaction with PVA and PDI-COOR used for compari-
son purposes in quantum yield measurements.
stable polyimides were prepared by Icil et al.25 based on
perylene-3,4,9,10-tetracarboxylic acid-bis(N,N0-dodecyl polyi-
mide) and by Wang et al.,26 who investigated their xero-
graphic electrical properties. Nevertheless, most of these
polymers were soluble only in strong polar solvents as a
consequence of the strong p–p interaction between the PDI
moieties. In more recent years, different strategies have
allowed to obtain PDI-based soluble polyimides,27 polyest-
ers,28 polyurethanes,29 and polyazomethines.30
water-soluble PDI derivative has been dispersed into vinyl
alcohol (VA)-containing polymers by blending and their
properties studied.37 The authors used a N,N’-bis(2-(1-piper-
azino)ethyl)-3,4,9,10-perylene tetracarboxylic acid diimidedi-
chloride, that can interact with the VA by hydrogen bonding.
However, it has been reported that planar objects, as big as
graphene nanosheets38 and graphite oxide (GO) laminates,39
can be covalently attached to PVA by simple esterification
remarkably altering the crystallinity of the polymer.39 There-
fore, the inclusion of smaller units should present no
difficulty.
An alternative approach for the incorporation of PDI moieties
in polymers involves the synthesis of PDI derivatives cova-
lently linked to polymers as side chains. Thus, PDI moieties
have been incorporated as side chain in polyacrylate31 and
polyisocyanide.32 Thus, inducing the solubility of PDI trough
covalent modification with a soluble polymer could be a great
advance. Even more, the immobilization of PDI into polymeric
matrices can be used to avoid the spontaneous intramolecular
aggregation in solution. In that sense, polyisocyanodipeptides
have been employed as scaffolds to tailor the chromophore–
chromophore interactions among PDI dyes covalently linked
to the aliphatic side-chains.33 Compared with blending, the
covalent linkage of PDI to a polymeric matrix gives homogene-
ous materials without phase segregation where the PDI moi-
eties are fixed inside the polymer matrix, avoiding self-
association.9
Here, we report the esterification of PVA with a water-insolu-
ble PDI, which has a carboxylic acid group in one of its nitro-
gen and long aliphatic chains in the other (Scheme 1). The
reactions reach up to 20% w/w of modification and the
obtained products show water solubility due to the PVA. The
esterified products retain the absorption and emission prop-
erties of the PDI dye giving photoluminescence in both solu-
tion and solid state.
RESULTS AND DISCUSSION
PDI-COOH is composed of a terminal carboxylic group that
can react with alcohols or amines giving ester or amides. The
esterification of PVA with PDI-COOH was carried out as
described in the experimental section. Special care was taken
in the purification of the products to ensure that no traces of
nonreacted PDI-COOH remained. Samples with different
degree of modification were prepared varying the molar frac-
tion of PDI and PVA in the reactor obtaining degrees of modi-
fication of 22, 21, and 8 wt % for samples 1, 2, and 3, respec-
However there exist a few examples of common polymers
covalently modified with PDI dyes. Homopolymers or block
copolymers from butyl acrylate, styrene, isoprene, and buta-
diene have been labeled with one perylenediimide per poly-
mer.34 Also, poly(methyl methacrylate) has been polymerized
in presence of perylene derivatives.35 Finally, short poly(eth-
ylene oxide) tails have been covalently attached to perylene
giving soluble materials in common solvents ranging from
alcohols to toluene.36
ꢁ
tively (Table 1). The products were soluble in water at 90 C
and dimethylsulfoxide (DMSO) due to the interaction of the
solvents with the hydroxyl moieties in the polymer. The solu-
bility depends on the final composition but solutions, as con-
centrated as 15 mg mLꢂ1, has been prepared for all samples.
Taking into account that samples PVAPery1 and 2 have very
Poly(vinyl alcohol) (PVA) is a water-soluble biodegradable
polymer with excellent film forming properties. Recently, a
TABLE 1 Composition of Different Samples of PVA Esterified with Perilenediimide
a
b
Samples
fp
% C
% H
% N
N/C
Fp
PVAPery1
PVAPery2
PVAPery3
a
6.9 ꢃ 10ꢂ3
5.4 ꢃ 10ꢂ3
1.7 ꢃ 10ꢂ3
53.70
52.9
52.9
10
0.58
0.56
0.2
1.1 ꢃ 10ꢂ2
1.1 ꢃ 10ꢂ2
3.8 ꢃ 10ꢂ3
0.22
0.21
0.08
9.8
9.2
fp is defined as the molar fraction of perylenediimide in the reactor.
Fp as the molar fraction of perylenediimide in the products.
b
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due to the actual composition of the samples (PVAPery3 does
not have the necessary content of PDI to observe this band).
Consequently, the intensity of the mentioned bands diminishes
as the content of PDI decreases (Fig. 1).
Second, a variation in the relative intensities of the charac-
teristics bands of PVA in the 1200–1000 cmꢂ1 region can be
clearly observed, resembling the results reported for the
esterification of PVA with GO.39 These bands are attributed
to the CAO of doubly H-bonded OH in crystalline regions
(1144 cmꢂ1) and CAO unbounded in amorphous zones
(1096 cmꢂ1).41 The intensity ratio of these bands (I1144
/
I1096) diminishes markedly for the esterified products, sug-
gesting a large decrease in the degree of crystallinity of
the modified polymer. These results were also confirmed by
X-ray diffraction (XRD; Supporting Information, Fig. S1).
The 1H NMR spectrum of the soluble PVAPery3 in DMSO-d6
is compared with that of neat PVA (Fig. 2). The latter exhib-
its the polymer backbone signals at ꢀ3.82 ppm (methine)
and ꢀ1.38 ppm (methylene) and the hydroxyl signals at 5–4
ppm from which the stereoregularity of PVA is estimated as
isotactic (mm): heterotactic (mr): syndiotactic (rr) of roughly
FIGURE 1 FTIR transmission spectra of PVA and PDI-modified
PVA.
similar composition, henceforth, we will base the discussion
on the results of samples PVAPery1 and 3 (Table 1).
To prove the success of the esterification reaction, the prod-
ucts were characterized by Fourier transform infrared spectra
(FTIR), hydrogen-nuclear magnetic resonance (1H NMR), and
X-ray photoelectron spectroscopy (XPS). The FTIR spectra of
the PDI-esterified PVA retained most of the bands of PVA,
some of them changed in intensity, and show additional bands
(Fig. 1). There are two features to remark. First, the most
intense bands of PDI-COOH40 appear weakly in the esterified
product PVAPery1, due to the low content of PDI with respect
to the polymer. Thus, a doublet centered at 1688 and 1648
cmꢂ1 assigned to the symmetric and antisymmetric stretching
vibrations of the carbonyl group can be perceived. These
bands seem to be displaced ꢀ10 cmꢂ1 at lower energy with
respect to PDI-COOH, due to the possible interaction with the
polymer matrix. In addition, a detailed examination of the
spectra reveals the presence of a very weak band at
1260 cmꢂ1 in PVAPery1. This band can be assigned to the
CAO stretching of the ester group, which appears as a strong
band in aromatic esters. Here is only perceived in PVAPery1
FIGURE 2 1H NMR spectra of PVA and PVAPery3 at room tem-
perature in DMSO-d6.
SYNTHESIS OF WATER-SOLUBLE PDI-FUNCTIONALIZED POLYMER, SALAVAGIONE ET AL.
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JOURNAL OF POLYMER SCIENCE: PART A: POLYMER CHEMISTRY DOI 10.1002/POLA
2:5:3.42 Upon the attachment to PDI-COOH the PVA proton
signals become much wider maintaining similar chemical
shifts. This behavior resembles the observation of PVA cova-
lently modified with carbon nanotubes43 and GO.39 However,
the effect is more noticeable in our case suggesting that a
higher degree of functionalization was achieved. Especially
interesting are the changes in the zone corresponding to
the hydroxyl protons resonances, which are resolvable in
terms of configurational sequences (inset in Fig. 2). Several
authors have concluded44 that the hydrogen-bonding tend-
ency, which is dominant for hydroxyl units in a mesoconfi-
guration, predominantly determines the hydroxyl proton
shielding. As hydrogen bonding leads to downfield shifts,
the chemical shifts of hydroxyl sequences resonances
increase when passing from iso (4.7 ppm) to hetero (4.5
ppm) and from hetero to syndio (4.2 ppm) triad. On the
other hand, it has been demonstrated that the reactivity of
substituent groups along the polymer chain can be influ-
enced by tactic sequence,39,45 where the substituent at mm
sequence exhibited higher reactivity than those at the rr
counterpart. Here, although the signals are broadened and
even overlap, it seems clear that exists, an increase in the
rr signal in detriment of the mm one for PVAPery, which
suggests that esterification reaction occur at isotactic
configuration.39
In addition, the presence of PDI units is confirmed by the
low signals at 5.1, 6.6, 6.8–7.8, 8.2, and 8.7 ppm (Supporting
Information, Fig. S2). These signals are in agreement with
those observed for the PDI-COOR (Experimental section).
Because of the low intensity of these signals and the error
associated with their quantification, they could not be used
to estimate the extent of modification. Therefore, we have
used elementary analysis, despite its uncertainties, to
roughly estimate the degree of modification (Table 1).
XPS results are summarized in Table S1 (see Supporting
Information). It is very interesting to note the changes in the
C1s signal with the increase of the content of PDI (Fig. 3). In
the product with lower content (PVAPery3), the C1s signal
was deconvoluted into only two peaks. The most intense
peak at 284.8 eV corresponds to the CAC bonds, whereas
the peak at 286.5 eV is assigned to the CAOH of the poly-
mer. However, an additional peak seems at 288.4 eV in the
sample with higher content of perylene (PVAPery1). This
new peak can be assigned to carboxyl carbon groups in PDI
(Scheme 1), and it only appears when a critical concentra-
tion of PDI is achieved. The XPS results for O1s reinforce the
above hypothesized [Fig. 3(c,d)]. The O1s signal for PVAPer3
was fitted to one peak centered at 532.7 eV, while the same
signal for PVAPery1 was deconvoluted into two peaks at
FIGURE 3 C1s XPS spectra of PVAPery1 (a) and PVAPery3 (b) and 1s spectra of PVAPery1 (c) and PVAPery3 (d).
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TABLE 2 Thermal Parameters for PVA and PVA Esterified with
Also, the thermal stability of this kind of polymers changes
when they are covalently modified. To investigate the effects
of the PDI groups on the thermal stability of the polymer
matrix, TGA were performed (Supporting Information, Fig.
S4). For the PVA, two processes were observed; the first one
due to the evolution of water from the polymer giving poly-
enes; and the second one correspond to the evolution of aro-
matic hydrocarbons coming from the rearrangement of these
polyenes.46 TGA results for PVAPery suggest that the pres-
ence of PDI improves the thermal stability remarkably. It is
clear that the temperature of maximum degradation rate for
the PDI-modified polymers increases more than 100 ꢁC as
occurred with PVA/GO systems.39,47,48 Figure S4 (Supporting
Information) also shows that despite a weight loss is
observed ꢀ200 ꢁC common in these systems, the onset of
decomposition for PVAPery is retarded. In addition, it seems
that the second process appears almost simultaneously with
the first one. That is, the presence of PDI stabilizes the water
elimination making the polyenes rearrange to aromatic
hydrocarbons as soon as they are generated.
Perylenediimide Obtained by DSC
Samples
Tg (ꢁC)
Tm (ꢁC)
DH (J gꢂ1
)
Xc (%)
PVA
82
225
83
51
PVAPery1
PVAPery2
PVAPery3
90.5
91.4
90.8
178
33.2
32.8
40
20.4
20.1
24.5
182.6
179
531.6 and 533 eV (Table S1), suggesting the presence of oxy-
gen atoms in at least two different environments. Finally, the
N1s signal was fitted to one peak with maxima at 400.5 eV
in both cases, which is logical as nitrogen atoms in perylene
are not involved in the esterification reaction (Supporting
Information, Fig. S3).
Once confirmed the covalent linkage of PDI units to PVA, it
would be interesting to study the effect of this modification
on the properties of the polymer as remarkable changes in
the crystalline parameters have already been observed in
similar systems.39 We have analyzed the melting and glass
transition (Tg) of the esterified polymers and compared it
with PVA.
Because of that one of the most interesting properties of PDI
derivatives is their fluorescence; it is interesting to study
whether the immobilization within the polymeric matrix
affect the fluorescence behavior. Figure 4(a) shows that the
absorption spectra of PVAPery in DMSO solution are almost
identical to those obtained for the PDI-COOH, suggesting that
the electronic absorption of the immobilized PDI is not
altered. All PVAPery samples show absorption bands at 528,
491, and 460 nm associated to the vibrational progression
(0!0, 0!1, and 0!2, respectively) of the S0!S1 electronic
transition.49 The same absorption spectra are obtained for
perylene-modified polymers in water solutions (Supporting
Information, Fig. S5). It has been reported that the absorb-
ance ratio between the 0!0 (528 nm), 0!1 (491 nm) tran-
sitions give information about aggregation by p-stacking.49
From Figure 4(a), the calculated A528/A491 ratio is 1.57, 1.42,
and 1.41 for the PDI-COOH, PVAPery1, and 3, respectively.
Although the variation of the ratio A528/A491 is low, the val-
ues obtained for the polymer-linked PDI are lower than that
for PDI-COOH, suggesting that the immobilization does not
diminish the association, as one might expect. However, for
systems involving polymers, intramolecular association or
folding should be considered in addition to the intermolecu-
lar self-association.50 Therefore, the system can be seen as
composed by rigid blocks of PDI and dynamic segments of
Regarding the heating scan, it can be observed that the
melting temperature (Tm) and the melting enthalpy (DHm)
are dramatically influenced by the presence of PDI moieties
(Table 2). In the modified products, the melting peak
broadens and shifts to much lower temperatures (ca. 45
ꢁC), and the crystallinity (XC) decreases remarkably (from
XC ¼ 0.51 for neat PVA to XC ¼ 0.2–0.25 for the products),
supporting the existence of covalent linkage between the
PVA and the PDI (Table 2). However, these changes are less
marked than those obtained for PVA with GO.39 Although,
in this case, the degree of functionalization is higher (and,
therefore, the presence of PDI groups) the steric factor has
no significant contribution as in the case of the huge GO
laminates.
It is interesting to remark that the noticeable changes
described above are nearly independent on the degree of
functionalization because similar behaviors are obtained for
all the esterified products.
In addition, the mobility of the polymer chains is also
affected by the covalent linkage of PDI groups (Table 2). The
Tg shifts to higher values for the esterified products due to
the effective covalent attachment of the PDI to the polymer
that prevents the segmental motions of the polymer chains.
Once more, the effect caused by the incorporation of PDI (Tg
PVA. For the PDI-modified PVA in water solution, the A528
/
A491 ratio was 1.36 suggesting that folding can also take pla-
ces in this case. Therefore, it can be concluded that the sol-
vents has not influence in the absorption behavior.
ꢁ
shifts ꢀ8–10 C) is less important than the obtained by GO-
Comparing the two PVAPery samples, the A528/A491 values
are identical although the concentration of chromophore is
higher in PVAPery1. Probably, the intermolecular self-assem-
bling in the sample with higher concentration of chromo-
phore (PVAPery1) is compensated by the intramolecular
folding on the PVAPery3, which has longer polymeric seg-
ments. Thus, the chromophore has higher probability to
meet other chromophore units in the same polymer.
modified PVA (35 ꢁC shift). Obviously, the presence of huge
rigid graphitic structures in the polymer chains restricts
more the movement than the smaller perylene.
As occurred with crystallinity and melting enthalpy, the Tg dis-
placement does not depend on the degree of functionalization.
It seems that above a threshold of modification, the polymer
becomes independent on the degree of functionalization.
SYNTHESIS OF WATER-SOLUBLE PDI-FUNCTIONALIZED POLYMER, SALAVAGIONE ET AL.
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JOURNAL OF POLYMER SCIENCE: PART A: POLYMER CHEMISTRY DOI 10.1002/POLA
FIGURE 4 Absorption and emission spectra of PDI-COOH (solid), PVAPery1 (dots) and PVAPery3 (dash) in DMSO solutions. Con-
centrations are 0.005 mg mLꢂ1 for PDI-COOH and 9 mg mLꢂ1 for the PDI-modified polymers.
Figure 4(b) shows the emission spectra of PVAPery1, PVAP-
ery3, and the corresponding to PDI-COOH in DMSO solution (k
¼ 470 nm). It can be seen that the immobilized chromophore
has retained the photoluminiscent properties as it has emis-
sion at 0!0 (540 nm), 0!2 (584 nm), and 0!3 (ꢀ625 nm).
In similar systems, it has been demonstrated that as the fold-
ing increases, the photoluminescence favors emissions to
higher vibronic ground states, thereby red-shifting the spectra.
Therefore, emission peaks at lower energy appear. The spectra
in Figure 4(b) can be deconvoluted into three main bands
with an important contribution of the band ꢀ630 for PVAPery
samples (Supporting Information, Fig. S6). From the integra-
tion of the deconvolution, bands can be observed that the rela-
tive intensity of the band at 630 nm is 0.25, 0.16, and 0.07 for
PVAPery1, PVAPery3, and PDI-COOH, respectively, suggesting
higher degree of aggregation for the polymeric samples. As
expected, the emission spectra of PDI-modified PVA in water
solution are identical to those obtained in DMSO.
From a practical point of view, to be applied in devices,
these materials need to retain their photoluminiscent prop-
erties in the solid state. Figure 5 shows the absorption and
emission spectrum of a film of PVAPery1. The film was pre-
pared by casting 0.5 mL of a DMSO solution (8 mg mLꢂ1
)
over a glass slide and evaporation at 50 ꢁC under vacuum.
The concentrations were varied to find similar absorbance
values. Qualitatively, it can be seen that the solid sample dis-
plays identical absorption spectrum than that in solution as
electronic bands at 467, 495, and 532 appear. Thus, the per-
ylene-modified PVA retains its electronic properties in the
solid state.
The solid-state emission has been collected using the front-
face illumination method [Fig. 5(b)]. As it can be perceived,
the emission spectrum is similar to that obtained in DMSO
solution showing slightly wider bands at 543 and 583 nm.
Therefore, the film retains its emission property, and good
photoluminescence is obtained that could be useful in
applications.
Using these solutions, the quantum yield of the PDI-modified
PVA were measured by using afford N,N0-(9-heptadecyl)pery-
lene-3,4:9,10-bis(dicarboximide) as reference (quantum yield
ꢀ1) and by using the comparative method of Williams
et al.51 We obtained the values of 0.18, 0.25, and 0.2 for ref-
erence PDI-COOR (Scheme 1), PVAPery 1, and 3, respectively.
These similar values confirm that in the PVA-functionalized
polymers, the PDI units retain their electronic nature, which
is not influenced by the presence of the polymer matrix and
can be seen as closed chromophores.
EXPERIMENTAL
Materials
4-Aminobenzoic acid, n-propyl 4-aminobenzoate, PVA (99þ%
hydrolyzed, Mw ꢀ 89,000–98,000), N,N-dicyclohexylcarbodii-
mide (DCC), and 4-dimethylaminopyrydine (DMAP, 99%)
were purchased from Aldrich. Methanol (OHCH3) and
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FIGURE 5 Solid state absorption
and emission of a PVAPery1 film
on glass.
tetrahydrofuran were purchased from Panreac, Spain. N-(8-
Pentadecyl)perylene-3,4:9,10-tetracarboxylic acid monoimide
monoanhydride was prepared according to literature.52
Synthesis of N-((Ethoxycarbonyl)phenyl)-N0-
(8-pentadecyl)perylene-3,4:9,10-bis(dicarboximide)
Under argon atmosphere, a well-stirred mixture of N-(8-pen-
tadecyl)perylene-3,4:9,10-tetracarboxylic acid monoimide
monoanhydride (250 mg, 0.42 mmol), n-propyl 4-aminoben-
zoate (450 mg, 2.50 mmol), zinc acetate dihydrate (60 mg,
Synthesis of N-(Carboxyphenyl)-N0-
(8-pentadecyl)perylene-3,4:9,10-bis(dicarboximide)
Under argon atmosphere, a well-stirred mixture of N-(8-penta-
decyl)perylene-3,4:9,10-tetracarboxylic acid monoimide mono-
anhydride (615 mg, 1.03 mmol), 4-aminobenzoic acid (0.98 g,
7.21 mmol), zinc acetate dihydrateꢁ (108 mg, 0.5 mmol), and
imidazole (4 g) was heated at 180 C for 2 h. After cooling to
room temperature, the resulting solid was disaggregated with
water and 1 M aqueous hydrochloric acid solution. The result-
ing precipitate was filtered, thoroughly washed with additional
hydrochloric acid solution, water, and methanol. The collected
solid was then dried under vacuum and purified by column
chromatography (silica gel, dichloromethane/methanol 8/2) to
afford N-(carboxyphenyl)-N0-(8-pentadecyl)perylene-3,4:9,10-
bis(dicarboximide), PDI-COOH, as a deep red solid in 68%
ꢁ
0.23 mmol) and imidazole (3 g) is heated at 180 C for 2 h.
After cooling to room temperature, the resulting solid is dis-
aggregated with water and a 1-M aqueous hydrochloric acid
solution. The resulting precipitate is filtered, thoroughly
washed with additional hydrochloric acid solution, water and
methanol. The collected solid is then dried under vacuum
and purified by column chromatography (silica gel, dichloro-
methane/hexane 9/1) to afford N-((ethoxycarbonyl)phenyl)-
N0-(8-pentadecyl)perylene-3,4:9,10-bis(dicarboximide) (PDI-
ꢁ
COOR) as a deep red solid in 80% yield with m. p. > 300 C.
1H NMR (CDCl3, 300 MHz) d ¼ 8.72–8.64 (m, 8H, Pery), 8.22
(d, J ¼ 8.8 Hz, 2H, Ph), 7.53 (d, J ¼ 8.8 Hz, 2H, Ph), 5.21 (bs,
1H, ANACH), 4.37 (bs, 2H, ACH2AO), 2.29 (bs, 4H, ACH2A),
1.88 (bs, 6H, ACH2A), 1.25–1.09 (m, 16H, ACH2A), 0.95–
0.77 (m, 9H, ACH3).
13C NMR (CDCl3, 75 MHz) d ¼ 163.50, 139.42, 135.75,
134.65, 135.32, 132. 34, 132.13, 132.09, 132.00, 129.73,
129.54, 129.44, 129.00, 128.88, 126.92, 126.58, 125.42,
124.77, 124.53, 124.16, 123.09, 67.46 (ACH2AO), 55.32
(ACHANA), 32.70, 31.92, 30.17, 30.03, 27.64, 23.00, 22.82,
14.62, 11.92. FTIR (KBr, cmꢂ1) m ¼ 2925, 2856, 1702, 1660,
1591, 1344, 1260, 702. Anal. Calcd. for C49H56N2O6: C:
76.52%; H: 7.34%; N: 3.64%; found: C: 76.36%; H: 7.28%;
N: 3.63%.
ꢁ
yield with m.p. > 300 C.
1H NMR (CDCl3, 300 MHz) d ¼ 8.75 (d, 2H, Pery), 8.69–8.64
(m, 6H, Pery), 8.10 (d, J ¼ 8.8 Hz, 2H, Ph), 7.42 (d, J ¼ 8.8
Hz, 2H, Ph), 4.94 (bs, 1H, ANACH), 1.95–1.77 (m, 4H,
ACH2A), 1.65–1.50 (m, 4H, ACH2A), 1.40–1.15 (m, 16H,
ACH2A), 0.95–0.77 (m, 6H, ACH3).
13C NMR (CDCl3, 75 MHz) d ¼ 167.86 (C¼¼O, w), 143.46,
139.68, 138.57, 136.26, 135.37, 135.30, 134.05, 133.14,
130.59, 127.92, 127.58, 127.11, 59.20 (ACHANA), 36.60,
36.05, 33.74, 33.47, 31.24, 26.85, 18.22. FTIR (KBr, cmꢂ1) m
¼ 2952, 2922, 2850, 1698, 1658, 1594, 1579, 1343, 811. MS
(FAB): 720 (Mþ, 45), 511 (MþACH(C7H15)2, 100). Anal.
Calcd. for C46H44N2O6: C: 76.63%; H: 6.16%; N: 3.89%;
found: C: 76.42%; H: 6.36%; N: 3.56%.
PVA-functionalization of PDI-COOH
Samples of PVA esterified with different amounts of PDI-
COOH in the feed were prepared (Table 1). The employed
SYNTHESIS OF WATER-SOLUBLE PDI-FUNCTIONALIZED POLYMER, SALAVAGIONE ET AL.
3619

JOURNAL OF POLYMER SCIENCE: PART A: POLYMER CHEMISTRY DOI 10.1002/POLA
SCHEME 2 Schematic representation of the esterification reaction of PVA with PDI-COOH.
esterification procedure for PDI-COOH was the following: dif-
ferent amounts of PDI-COOH (43, 35, and 11 mg for PVA-
Pery1, 2, and 3, respectively) and 0.4 g of PVA (9 mmol
equivalent to OH group) were suspended in DMSO (20 mL).
The suspension was gently stirred and maintained at 70 ꢁC
under nitrogen for 2 h. Then, a solution of DCC (1.85 g, 9
mmol) and DMAP (0.135 g, 1.1 mmol) in DMSO (20 mL)
were added, and the resulting mixture was stirred at 40 ꢁC
for another 3 days (Scheme 2). The coagulation of the prod-
uct was accomplished by adding the suspension into 400 mL
of methanol under vigorous stirring. The solid was filtered,
sample sealed in aluminum pans. The samples were heated
from room temperature to 240 ꢁC, maintained at this tem-
perature during 5 min, and then cooled to room temperature
and heated again to 240 ꢁC. The heating and cooling rates
were 10 ꢁC minꢂ1 in all cases. The transition temperatures
were taken as the peak maximum in the calorimetric curves.
UV–vis absorption spectra were recorded on a Perkin–Elmer
Lambda 40 spectrophotometer and photoluminescence spec-
tra on a JASCO FP6200 spectrometer. For these measure-
ments, 8 mg mLꢂ1 solutions of the PDI-modified polymer
were prepared by using DMSO as solvent. Fluorescence
quantum yields were measured using N,N0-(9-hepte-
decyl)3,4:9,10-perylenediimide as reference (quantum yield
ꢀ1) by means of the comparative method of Williams
et al.51
ꢁ
washed with methanol, and dried at 50 C under vacuum. To
eliminate the remainings of nonreacted PDI-COOH, the prod-
uct was redissolved in hot water, centrifuged at a high speed
(16,000 rpm) during 1 h and the supernatant colored solu-
tion coagulated with methanol. The procedure was repeated
twice.
Fluorescence spectra of films were measured with front-face
geometry at angles of 40ꢁ and 50ꢁ to the excitation and
emission beams, respectively. The holder position was that
the scattered light was eliminated from the emission beam
reaching the detector.
The actual composition of the samples was calculated by
using the N/C ratio from elementary analysis (Table 1). We
suppose that the final product can be seen as a copolymer of
VA and PDI-modified VA (Scheme 2). Thus, for PVA
homopolymers, the N/C ratio is zero, and for PVAPery, the
Elemental analysis was performed on a LECO CHNS-932
instrument.
theoretical N/C ratio is 4.9 ꢃ 10ꢂ2
.
Physical and Analytical Methods
1
The H NMR spectra were recorded at 400 MHz on a Varian
Inova 400 spectrometer at room temperature with dimethyl
sulfoxide-d6 (10 wt % solutions) as a solvent.
CONCLUSIONS
We have demonstrated that PDI derivatives can be covalently
linked to a biocompatible polymer. The incorporation of the
chromophore alters remarkably the properties of the poly-
mer. However, the immobilized PDI retains its interesting op-
tical properties, showing photoluminescence in solution as
well as in solid state. The fact that the products described
here are water-soluble makes PVAPery promising as fluores-
cent labels for biologically active probes.
FTIR of the samples in the transmission mode were obtained
in KBr pellets by using a Perkin–Elmer System 200 spec-
trometer with a 4 cmꢂ1 resolution.
XPS spectra were recorded using an Escalab 200R spectrom-
eter (ICP-CSIC, Madrid) with a hemispherical analyzer oper-
ated on a constant pass energy mode and nonmonochromat-
ized Mg Ka X-ray radiation (hm ¼ 1253.6 eV) at 10 mA and
12 kV. Data analysis was performed with the ‘‘XPS peak’’ pro-
gram. The spectra were decomposed by the least-squares fit-
ting routine using a Gauss–Lorentz product information after
subtracting a Shirley background.
A natural extension of this research is to study the depend-
ence of the optical properties on external parameters such
as temperature, especially above the Tg of the system. Also,
it is our intention to compare these results with physical
mixtures and, finally, study the possibility of using these
materials as solid-sate lasers.
The thermogravimetric analysis (TGA) was done in a TGA
Q500 equipment from TA instruments. Samples were dried
under dynamic vacuum before the experiments and then
placed in a platinum pan. The loss of weight was monitored
Financial support from the Spanish Ministry of Science and
Innovation (MICINN) (MAT2009-09335) the Comunidad
Auto´noma de Madrid (S2009/MAT-1467), the UCM-BSCH joint
project (GR58/08) and the MCyT of Spain (CTQ2007-60459)
are grateful acknowledged. H.J.S. thanks MICINN by a Ramon y
Cajal research contract. The authors thank Prof J. L. Garcı´a
Fierro (ICP-CSIC) for XPS experiments and Dr. M. Liras by help
in the Front-face fluorescence measurements.
ꢁ
from room temperature to 950 C using a heating rate of 10
ꢁC minꢂ1 in a nitrogen atmosphere.
The crystallization and melting behavior were investigated
by DSC using a Mettler TA4000/DSC30. The experiments
were carried out in nitrogen atmosphere by using ꢀ5 mg of
3620
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ARTICLE
11 (a) Pisula, W.; Kastler, M.; Wasserfallen, D.; Robertson, J.
REFERENCES AND NOTES
W. F.; Nolde, F.; Kohl, C.; Mullen, K. Angew Chem Int Ed 2006,
¨
1 (a) Zollinger, H. Color Chemistry, 3rd. ed.; VCH: Weinheim,
2003; (b) Herbst, W.; Hunger, K. Industrial Organic Pigments:
Production, Properties, Applications, 2nd ed.; Wiley-VCH:
Weinheim, 1997.
45, 819–823; (b) Bullock, J. E.; Carmieli, R.; Mickley, S. M.;
Vura-Weis, J.; Wasielewski, M. R. J Am Chem Soc 2009, 131,
11919–11929.
12 For a recent review on functional supramolecular architec-
2 (a) Struijk, C. W.; Sieval, A. B.; Dakhorst, J. E. J.; VanDijk, M.;
Kimkes, P.; Koehorst, R. B. M.; Donker, H.; Schaafsma, T. J.;
Picken, S. J.; van de Craatsm, A. M.; Warman, J. M.; Zuilhof,
tures based on PDI dyes, see: Wurthner, F. Chem Commun
¨
2004, 1564–1579.
13 (a) Rohr, U.; Kohl, C.; Mullen, K.; Van de Craats, A.; War-
¨
H.; Sudholter, E. J. R. J Am Chem Soc 2000, 122, 11057–11066;
¨
man, J. J Mater Chem 2001, 11, 1789–1799; (b) Adachi, M.;
Nagao, Y. Chem Mater 2001, 13, 662–669; (c) Tam-Chang,
S.-W.; Seo, W.; Iverson, I. K.; Casey, S. M. Angew Chem Int Ed
Engl 2003, 42, 897–900; (d) Braeken, E.; De Cremer, G.; Marsal,
P.; Pepe, G.; Mullen, K.; Vallee, R. A. L. J Am Chem Soc 2009,
131, 12201–12210.
(b) Dimitrakopoulos, C. D.; Malenfant, P. R. L. Adv Mater 2002,
14, 99–117; (c) Palermo, V.; Schwartz, E.; Liscio, A.; Otten, M.
B. J.; Mullen, K.; Nolte, R. J. M.; Rowan, A. E.; Samori, P. Soft
Matter 2009, 5, 4680–4686.
3 (a) Halls, J. J. M.; Friend, R. H. Synth Met 1997, 85,
1307–1308; (b) Breeze, A. J.; Salomon, A.; Ginley, D. S.; Gregg,
14 You, C.-C.; Wurthner, F.
J Am Chem Soc 2003, 125,
¨
B. A.; Tillmann, H.; Horhold H.-H. Appl Phys Lett 2002, 81,
¨
9716–9725.
3085–3087; (c) Yakimov, A.; Forrest, S. R. Appl Phys Lett 2002,
80, 1667–1669; (d) Zhou, E.; Tajima, K.; Yang, C.; Hashimoto, K.
J Mater Chem 2010, 20, 2362–2368.
15 Langhals, H.; Saulich, S. Chem Eur J 2002, 8, 5630–5643.
16 (a) Hua, J.; Meng, F.; Ding, F.; Tian, H. Chem Lett 2004, 33,
432–434; (b) Go´ mez, R.; Segura, J. L.; Mart´ın, N. Org Lett 2005,
7, 717–720; (c) Graja, A.; Lewandowska, K.; Laskowska, B.; Lap-
inski, A.; Wrobel, D. Chem Phys 2008, 352, 339–344.
4 (a) Sussmeier, F.; Langhals, H. Eur
J
Org Chem
¨
2001,607–610; (b) Tautzenberger, A.; Lorenz, S.; Kreja, L.; Zeller,
A.; Musyanovych, A.; Schrezenmeier, H.; Landfester, K.; Mai-
laender, V.; Ignatius, A. Biomaterials 2010, 31, 2064–2071.
17 (a) Weil, T.; Wiesler, U. M.; Herrmann, A.; Bauer, R.; Hofk-
5 (a) He, X.; Liu, H.; Li, Y.; Wang, S.; Wang, N.; Xiao, J.; Xu, X.;
Zhu, D. Adv Mater 2005, 17, 2811–2815; (b) Zang, L.; Liu, R.;
Holman, M. W.; Nguyen, K. T.; Adams, D. M. J Am Chem Soc
2002, 124, 10640–10641; (c) Zhang, X.; Rehm, S.; Safont-Sem-
pere, M. M.; Wuerthner, F. Nat Chem 2009, 1, 623–629.
ens, J.; De Schryver F. C.; Mullen, K. J Am Chem Soc 2001,
¨
123, 8101–8108; (b) Weil, T., Reuther E.; Mullen, K. Angew
¨
Chem Int Ed Engl 2002, 41, 1900–1904; (c) Gronheid, R.; Hofk-
ens, J.; Kohn, F.; Weil, T.; Reuther, E.; Mullen, K.; De Schryver,
¨
¨
F. C. J Am Chem Soc 2002, 124, 2418–2419; (d) Cotlet, M.;
Vosch, T.; Habuchi, S.; Weil, T.; Mullen, K.; Hofkens, J.; De
¨
6 (a) Calzado, E. M.; Villalvilla, J. M.; Boj, P. G.; Quintana, J. A.;
Go´ mez, R.; Segura, J. L.; Dı´az Garc´ıa, M. A. Appl Opt 2007, 46,
3836–3842; (b) Calzado, E. M.; Villalvilla, J. M.; Boj, P. G.; Quin-
tana, J. A.; Go´ mez, R.; Segura, J. L.; Dı´az Garcı´a, M. A. J Phys
Chem C 2007, 111, 13595–13605.
Schryver F. C. J Am Chem Soc 2005, 127, 9760–9768; (e) Dabir-
ian, R.; Palermo, V.; Liscio, A.; Schwartz, E.; Otten, M. B. J.; Fin-
layson, C. E.; Treossi, E.; Friend, R. H.; Calestani, G.; Mullen, K.;
Nolte, R. J. M.; Rowan, A. E.; Samori, P. J Am Chem Soc 2009,
131, 7055–7063.
7 Yukruk, F.; Dogan, A. L.; Canpinar, H.; Guc, D.; Akkaya E. U.
18 (a) You, C.-C.; Saha-Moller, C. R.; Wurthner, F. Chem Com-
¨
¨
Org Lett 2005, 7, 2885–2887.
mun 2004, 2030–2031; (b) Chen, S.; Liu, Y.; Qiu, W.; Sun, X.;
Ma, Y.; Zhu, D. Chem Mater 2005, 17, 2208–2215.
8 (a) Malenfant, P. R. L.; Dimitrakopoulos, C. D.; Gelorme, J. D.;
Kosbar, L. L.; Graham, T. O.; Curioni, A.; Andreoini, W. Appl
Phys Lett 2002, 80, 2517–2519; (b) Chesterfield, R. J.; McKeen,
J. C.; Newman, C. R.; Frisbie, C. D. J Appl Phys 2004, 95,
6396–6405; (c) Rost, C.; Gundlach, D. J.; Karg, S.; Riess, W. J
Appl Phys 2004, 95, 5782–5787; (d) Liu, C.; Liu, Z.; Lemke, H. T.;
Tsao, H. N.; Naber, R. C. G.; Li, Y.; Banger, K. R.; Mullen, K.;
Nielsen, M. M.; Sirringhaus, H. Chem Mat 2010, 22, 2120–2124.
19 (a) Segura, J. L.; Go´ mez, R.; Reinold, E.; Bauerle, P. Org Lett
¨
2005, 7, 2345–2348; (b) Segura, J. L.; Go´ mez, R.; Blanco, R.;
Reinold, E.; Bauerle, P. Chem Mater 2006, 18, 2834–2847; (c)
¨
Go´ mez, R.; Veldman, D.; Blanco, R.; Seoane, C.; Segura, J. L.;
Janssen, R. A. J. Macromolecules 2007, 40, 2760–2772; (d)
Montilla, F.; Esquembre, R.; Go´ mez, R.; Blanco, R.; Segura, J.
L. J Phys Chem C 2008, 112, 16668–16674; (e) Blanco, R.;
Go´ mez, R.; Seoane, C.; Segura, J. L.; Mena-Osteritz, E.; Ba¨uerle,
P. Org Lett 2007, 9, 2171–2174.
9 (a) Ego, C.; Marsitzky, D.; Becker, S.; Zhang, J.; Grimsdale, A.
C.; Mullen, K.; MacKenzie, J. D.; Silva, C.; Friend, R. H. J Am
¨
Chem Soc 2003, 125, 437–443; (b) Hill, Z. B.; Rodovsky, D. B.;
Leger, J. M.; Bartholomew, G. P. Chem Commun 2008,
6594–6596.
20 Yang, M.; Xu, S.; Wang, J.; Ye, H.; Liu, X. J Appl Polym Sci
2003, 90, 786–791.
21 Kohl, C.; Weil, T.; Qu, J.; Mullen, K. Chem Eur J 2004, 10,
¨
10 (a) Langhals, H.; Wagner, C.; Ismael, R. New J Chem 2001,
25, 1047–1049; (b) Rybtchinski, B.; Sinks, L. E.; Wasielewski, M.
R. J Am Chem Soc 2004, 126, 12268–12269; (c) Rybtchinski, B.;
Sinks, L. E.; Wasielewski, M. R. J Phys Chem A 2004, 108,
7497–7505; (d) Vosch, T.; Fron, E.; Hotta, J.-I.; Deres, A.; Uji-i,
H.; Idrissi, A.; Yang, J.; Kim, D.; Puhl, L.; Haeuseler, A. J Phys
Chem C 2009, 113, 11773–11782.
5297–5310.
22 Turkmen, G.; Erten-Ela, S.; Icli, S. Dyes Pigm 2009, 83,
¨
297–303.
23 Tian, H.; Liu, P.-H.; Zhu, W.; Gao, E.; Wu, D.-J.; Cai S.
J Mater Chem 2000, 10, 2708–2715.
SYNTHESIS OF WATER-SOLUBLE PDI-FUNCTIONALIZED POLYMER, SALAVAGIONE ET AL.
3621

JOURNAL OF POLYMER SCIENCE: PART A: POLYMER CHEMISTRY DOI 10.1002/POLA
24 Ghassemi, H.; Hay, A. S. Macromolecules 1994, 27,
37 Donati, F.; Pucci, A.; Ruggeri, G. Phys Chem Chem Phys
4410–4412.
2009, 11, 6276–6282.
25 Icil, H.; Icil, S. J Polym Sci Part A: Polym Chem 1997, 35,
38 Veca, L. M.; Lu, F.; Meziani, M. J.; Cao, L.; Zhang, P.; Qi, G.;
2137–2142.
Qu, L.; Shrestha, M.; Sun, Y.-P. Chem Commun 2009, 2565–2567.
26 Wang, Z. Y.; Qi, Y.; Gao, J. P.; Sacripante, G. G.; Sundarara-
39 Salavagione, H. J.; Mart´ınez, G.; Go´ mez, M. A. Macromole-
jan, P. R.; Duff, J. D. Macromolecules 1998, 31, 2075–2079.
cules 2009, 42, 6331–6334.
27 (a) Huang, W.; Yan, D.; Lu, Q.; Huang, Y. Eur Polym J 2003,
39, 1099–1104; (b) Yuney, K.; Icil H. Eur Polym J 2007, 43,
2308–2320.
40 Rodriguez-Llorente, S.; Aroca A. R.; Duff, J.; de Saja, J. A.
Thin Solid Films 1998, 317, 129–132.
41 Mallapragada, S. K.; Peppas, N. A. J Polym Sci Part B:
28 Klok, H. A.; Becker, S.; Schuch, F.; Pakula T.; Mullen, K. Mac-
Polym Phys 1996, 34, 1339–1346.
romol Biosci 2003, 3, 729–741.
42 (a) Moritani, T.; Kuruma, I.; Shibatani, K.; Fujiwara, Y. Mac-
romolecules 1972, 5, 577–580; (b) Wu, T. K.; Obenall, D. W.
Macromolecules 1973, 6, 582–584.
29 (a) Kim, D. W.; Lee, C. W.; Joo, S. W.; Gong, M. S. J Lumin
2002, 99, 205–212; (b) Jancy, B.; Asha, S. K. J Polym Sci Part A:
Polym Chem 2009, 47, 1224–1235.
43 Lin, Y.; Zhou, B.; Fernando, K. A. S.; Liu, P.; Allard, L. F.;
30 Kaya, I.; Koyuncu, S.; Culhaoglu, S. Polymer 2008, 49,
Sun, Y.–P. Macromolecules 2003, 36, 7199–7204.
703–714.
44 Wu, T. K.; Ovenall, D. W. Macromolecules 1974, 7, 776–779.
31 Lindner, S. M.; Thelakkat, M. Macromolecules 2004, 37,
45 (a) Jameison, F. A.; Schilling, F. C.; Tonelli, A. E. Macromo-
lecules 1986, 19, 2168–2173; (b) Imai, K.; Shiomi, T.; Tezuka, Y.;
Tsukahara, T. Polym J 1991, 23, 1105–1109; (c) Mart´ınez, G.
J Polym Sci Part A: Polym Chem 2006, 44, 2476–2486.
8832–8835.
32 (a) Hernando, J.; de Witte, P. A. J.; van Dijk, E. M. H. P.; Kor-
terik, J.; Nolte, R. J. M.; Rowan, A. E.; Garc´ıa-Parajo´ , M. F.; van
Hulst N. F. Angew Chem Int Ed Engl 2004, 43, 4045–4049; (b)
Foster, S.; Finlayson, C. E.; Keivanidis, P. E.; Huang, Y.-S.;
Hwang, I.; Friend, R. H.; Otten, M. B. J.; Lu, L.-P.; Schwartz, E.;
Nolte, R. J. M.; Rowan, A. E. Macromolecules 2009, 42,
2023–2030.
46 Ballistreri, A.; Foti, S.; Montaudo, G.; Scamporrino, E.
J Polym Sci Polym Chem Ed 1980, 18, 1147–1153.
47 Matsuo, Y.; Hatase, H.; Sugie, Y. Chem Mater 1998, 10,
2266–2269.
33 Finlayson, C. E.; Friend, R. H.; Otten, M. B. J.; Schwartz, E.;
48 Salavagione, H. J.; Mart´ınez, G.; Go´ mez, M. A. J Mater
Cornelissen, J. J. L. M.; Nolte, R. J. M.; Rowan, A. E.; Samorı`,
Chem 2009, 19, 5027–5032.
P.; Palermo, V.; Liscio, A.; Peneva, K.; Mullen, K.; Trapani, S.;
¨
49 Wang, W.; Han, J. J.; Wang, L. Q.; Li, L. S.; Shaw, W. J.; Li
Beljonne, D. Adv Funct Mater 2008, 18, 3947–3955.
A. D. Q. Nano Lett 2003, 3, 455–458.
34 Bowden, N. B.; Willets, K. A.; Moerner, W. E.; Waymouth, R.
50 Li, A. D. Q.; Wang, W.; Wang, L.-Q. Chem Eur J 2003, 9,
M. Macromolecules 2002, 35, 8122–8125.
4594–4601.
35 El-Shaarawy, M. G.; Mansour, A. F.; El-Bashir, S. M.; El-
51 Williams, A. T. R.; Winfield, S. A.; Miller, J. N. Analyst 1983,
Mansy, M. K.; Hammam, M.
793–805.
J Appl Polym Sci 2003, 88,
108, 1067–1071.
36 Williams, M. E.; Murray, R. W. Chem Mater 1998, 10,
52 Rajaram, S.; Armstrong, P. B.; Kim, B. J.; Frechet J. M. J.
3603–3610.
Chem Mater 2009, 21, 1775–1777.
3622
INTERSCIENCE.WILEY.COM/JOURNAL/JPOLA