Versatile route to functionalized vinylic addition polynorbornenes

Article abstract of DOI:10.1021/ma101137z

Vinylic addition polynorbornenes bearing functional groups can be obtained in a versatile way by nucleophilic substitution of a halogen in new vinylic haloalkyl polynorbornenes. The latter are obtained by vinylic homo and copolymerization of norbornene and haloalkyl norbornenes catalyzed by [Ni(C ₆F₅)₂(SbPh₃)₂]. This method circumvents the problem of catalyst deactivation encountered in classical copolymerizations with polar monomers. The content of substituted monomer in the copolymers is in the range 26-59%, depending on the monomer ratio in the feed. Nucleophilic substitution reactions afford polymers with ester, cyano, phenylthio, or azido groups in the same wide range of composition. Click chemistry on the azido polynorbornenes give polynorbornenes with pendant triazole groups.

Full text of DOI:10.1021/ma101137z

7482 Macromolecules 2010, 43, 7482–7487
DOI: 10.1021/ma101137z
Versatile Route to Functionalized Vinylic Addition Polynorbornenes
ꢀ
Sheila Martınez-Arranz, Ana C. Albeniz,* and Pablo Espinet*
´
ꢀ
IU CINQUIMA/Quımica Inorganica. Universidad de Valladolid. 47071-Valladolid. Spain
Received May 21, 2010; Revised Manuscript Received July 27, 2010
ABSTRACT: Vinylic addition polynorbornenes bearing functional groups can be obtained in a versatile
way by nucleophilic substitution of a halogen in new vinylic haloalkyl polynorbornenes. The latter are
obtained by vinylic homo and copolymerization of norbornene and haloalkyl norbornenes catalyzed by
[Ni(C6F5)2(SbPh3)2]. This method circumvents the problem of catalyst deactivation encountered in classical
copolymerizations with polar monomers. The content of substituted monomer in the copolymers is in the
range 26-59%, depending on the monomer ratio in the feed. Nucleophilic substitution reactions afford
polymers with ester, cyano, phenylthio, or azido groups in the same wide range of composition. Click chemis-
try on the azido polynorbornenes give polynorbornenes with pendant triazole groups.
Introduction
of the substituted monomers, at least with the existing catalytic
systems.
The vinylic polymerization of norbornene affords materials
with a saturated aliphatic backbone. They exhibit a combination
of properties, such as high stability and transparency, that make
them ideal for many electronic, optical, and other applications.1,2
However, the absence of polar groups in the polymer lead to low
adherence to surfaces, which is a drawback in the use of the poly-
mers for the construction of devices. Polynorbornenes with polar
groups could be accessed by addition polymerization of function-
alized norbornenes or by copolymerization of these monomers
with norbornene, but these are difficult reactions, and many cata-
lytic systems that work very well in the polymerization of norbornene
have produced only poor to modest results when tested for substi-
tuted norbornenes. For instance, early transition metal catalysts
are deactivated by the presence of a polar substituent (usually an
oxygen containing functionality) in the monomer.3 On the other
hand, late transition metal complexes such as Ni or Pd derivatives
have proved more resistant to deactivation,2c,4 but they afford
low polymer yields.5 When copolymerization takes place with
other alkenes, the incorporation of the polar monomer, a norbor-
nylene ester, alcohol, or aldehyde, is often low.6,7
In addition to the physical properties induced by the presence
of functions in the polymer, there is also an interest in function-
alized polymers related to supported transition-metal catalysis.
In this respect, it is desirable to have easy and versatile laboratory
methods to prepare polymers with different flexibility. The poly-
norbornene skeleton is a chemically stable structure that could be
used, providedanappropriate methodology for functionalization
is made available.
Here, we have developed an interesting approach to vinylic addi-
tion polynorbornenes with polar functionalities that circumvents
the problems of the classical polymerization synthetic approach.
We have found out that norbornene derivatives with a halogen
group can be easily homopolymerized and, more interestingly,
copolymerized with norbornene to give copolymers with a wide
range of incorporation of the functional monomer. Subsequent
halogen substitution in the halogenated polymer leads easily to
functionalized polynorbornenes with pendant functional groups
that are difficult or impossible to access by catalytic polymerization
Results and Discussion
Synthesis of the Halogenated Polynorbornenes. The halo-
alkyl substituted norbornenes 1-4 (eq 1) were synthesized by
Diels-Alder reactions of cyclopentadiene and the corre-
sponding terminal 1-haloalkenes. All the NB derivatives
are a mixture of endo (major) and exo (minor) isomers in a
ratio close to endo:exo =85:15.
Catalysts [Ni(Rf)2L2] (Rf = C6Cl2F3, C6F5; L = AsPh3,
SbPh3) are very active in the polymerization of norbornene,8
and active in the copolymerization of stannylated norbor-
nenes with NB.9 Other [Ni(Rf)2L2] complexes (L = THF,
toluene, 1,2-dme) have also been used in the polymerization
of norbornene.10 In this case, the homopolymerization and
copolymerization reactions of monomers 1-4 with norbor-
nene were carried out using [Ni(C6F5)2(SbPh3)2] (5) as
catalyst and afforded polymers 6-9 (Scheme 1). Table 1
collects relevant data for the polymerization reactions. The
molar ratio of monomers in the copolymer is given as a/b=
NB/NBCH2X. Although halogenated norbornenes are
sometimes included in the broad general formulations of
potential monomers in the patent literature regarding the
polymerization of norbornenes, this is, to our knowledge, the
first reported halogenated vinylic addition polynorbornenes
with variable content of the halo-containing functionality.
The polymerization or copolymerization reactions were
carried out using a molar amount of catalyst 5 between 1%
and 0.5%. Although 5 is extremely active in the polymeriza-
tion of NB, it is less effective in the polymerization of sub-
stituted norbornenes. Catalyst loadings below 0.5% of the
total molar amount of monomers used are not recommended
(cf. entries 4, 7, and 8, Table 1).
The halogenated monomers undergo homopolymeriza-
tion (entries 1 and 9-11, Table 1) with moderate or good
*Corresponding authors. E-mail: (A.C.A.) albeniz@qi.uva.es; (P.S.)
espinet@qi.uva.es.
pubs.acs.org/Macromolecules
Published on Web 08/30/2010
r 2010 American Chemical Society

Article
Macromolecules, Vol. 43, No. 18, 2010 7483
yields. The yield improves as the carbon bearing the halogen
substituent is farther away from the bicyclic unit, so the
homopolymerization is very efficient for 3 and 4.
and 4 can be copolymerized with NB similarly as 2 (entries
12-14, Table 1). For the longer chain monomers, a higher
incorporation of the bromoalkylnorbornene is observed
compared to 2 (cf. entries 4, 13, and 14). A rough estimation
of the reactivity ratios for both couples NB/3 and NB/4
give similar values around rNB, 0.7, and rNB-Br, 0.4, which
show a higher incorporation rate of 3 or 4 vs 2 when reacted
with NB.
As for the morphology of the polymers and copolymers,
the 1H and 13C{1H} NMR spectra show characteristic -CH2X
signals and broad resonances for the NB skeleton. The absence
of resonances in the olefinic region supports a vinylic poly-
merization mechanism. The 13C{1H} NMR spectra point to
an exo norbornene enchained polymer, as they do not show
signals around 20 ppm.12 The 13C resonance assignments
were made with the help of 1H-13C HMQC experiments and
previous literature data.10,12 The polymers show C-C6F5
end groups (in the 19F NMR spectra, Fortho region).13 This
suggests an insertion mechanism of polymerization initiated
by insertion of NB or the halogenated norbornene into the
Ni-C6F5 bond, as reported before for related systems.8-10
DSC measurements did not show a clear heat capacity change
for all the polymers, so Tg could not be determined in
all cases. In the few cases that Tg could be measured the
values were high (around 250 °C), as it is the case for other
polynorbornenes.5a,6c,10
Functionalization of the Halogenated Polynorbornenes.
Different nucleophilic substitution reactions were carried
out on the haloalkyl polynorbornenes, as shown in Scheme 2,
producing new polynorbornenes with ester, cyano, thio, or
azido substituents.
Table 2 collects the new polymers obtained from copoly-
mers 7 of different composition. The bromoalkyl poly-
norbornenes were chosen for these reactions, as they undergo
the reactions more readily than the chloroalkyl derivatives.
For instance, the reaction of a chloroalkyl polynorbornene
of composition NB:1=1.7:1 in the same conditions used for
the bromo copolymer in entry 4 of Table 2, lead to only 35%
of Cl substitution vs 95% for Br substitution. The nucleophiles
were generated by in situ deprotonation of the corresponding
The copolymerization reaction conditions with norbor-
nene were explored for the halogenated monomer 2. The
incorporation of the haloalkyl monomers in the copolymer
can be roughly controlled by the monomer ratio in the feed,
as shown in Table 1 for the copolymerization of NB and 2
(entries 2-6). The NB content in the copolymer is always
higher than in the initial monomer feed showing its expected
higher reactivity. According to the data in Table 1 (entries
2-5) the reactivity ratios of NB and 2 can be determined as
rNB, 1.11, and r2, 0.29. On the other hand, the analysis of the
remaining unreacted monomers 2, after copolymerization is
finished, shows that the original percentage of 85% endo has
increased to 90-97%, depending on the actual experiment.
This change indicates a preference for incorporation of the
exo isomer, as found for other substituted norbornenes,11
not as large as observed for norbornene copolymers with
oxygen functionalities such as esters or aldehydes, where the
coordination of the endo isomers to the metal center as an
η2-alkene, O-donor chelating ligand blocks the metal center
and halts further polymer growth.11b In our case, compar-
ison of the yields in copolymer with the initial masses and the
copolymer final composition, shows that a quantitative
conversion of NB has occurred. Copolymers containing
percentages of incorporation of the halogenated monomer
2 in the range between 59% (a/b=0.7, entry 2, Table 1) and
26% (a/b=2.8, entry 5, Table 1) could be obtained by tuning
the composition of the feed. The copolymers are white solids,
soluble in CH2Cl2 or THF. They show unimodal distribu-
tions in GPC and a polydispersity in the range 1-2. As observed
in other copolymerization reactions of norbornene mono-
mers,9 the molecular weight of the copolymers increases with
the NB content (cf. entries 2 to 6, Table 1). Monomers 1, 3,
Scheme 1. Polymerization of Haloalkylnorbornenes
Scheme 2. Synthesis of Functionalized Polynorbornenes
Table 1. Homo and Copolymerization Reactions of Monomers 1-4 and Norbornene to give polymers 6-9.a
feed composition NB:NBCH2X:[Ni]b
isolated yield (%)c
copolymer, a/bd (a/b = NB/NBCH2X)
Mw
Mw/Mn
e
e
entry
1
2
3
4
NB:2:[Ni] = 0:75:1
NB:2:[Ni] = 25:75:1
NB:2:[Ni] = 50:75:1
NB:2:[Ni] = 75:75:1
NB:2:[Ni] = 150:75:1
NB:2:[Ni] = 225:75:1
NB:2:[Ni] = 100:100:1
NB:2:[Ni] = 150:150:1
NB:1:[Ni] = 0:75:1
NB:3:[Ni] = 0:75:1
NB:4:[Ni] = 0:75:1
NB:1:[Ni] = 75:75:1
NB:3:[Ni] = 75:75:1
NB:4:[Ni] = 75:75:1
50
75
70
74
86
76
55
2
55
83
94
77
80
78
7, 0
13 655
32 210
40 578
54 074
71 020
63 007
49 221
1.54
1.75
2.12
1.40
1.45
1.55
1.54
7, 0.7
7, 1.2
7, 1.7
7, 2.8
7, 2.8
7, 2.1
5
6
7f
8f
9
6, 0
8, 0
9, 0
6, 1.6
8, 1.3
9, 1.4
60 951
77 750
189 941
116 048
728 988
856 839
1.00
1.04
1.63
1.19
1.63
1.89
10
11
12
13
14
a The reactions were carried out using CH2Cl2 as solvent (6.25 mL total volume of the reaction mixture) at 28 °C for 24 h. b Molar ratio in the feed;
[Ni] = [Ni(C6F5)2(SbPh3)2] (5), 0.0356 mmol, unless otherwise noted. c Yields are referred to the total monomer mass. d a/b was determined by
quantitative analyses of halogen in the copolymer. e Determined by GPC using polystyrene standards. f [Ni] = 0.0267 mmol for entry 7 and [Ni] = 0.0178
mmol for entry 8.

7484 Macromolecules, Vol. 43, No. 18, 2010
Table 2. Functionalization of Copol-NB-NBCH2Br according to Scheme 2
Martınez-Arranz et al.
Copol-NB-NBCH2Br (7),
Copol-NB-NBCH2Nu,
entry
NB:2 (2, mol %) in copolymera
isolated yield (%)
Nu (mol %)b
Mw
Mw/Mn
1
2
3
4
5
6
7
8
9
0:1 (100)
0.7:1 (58.8)
1.2:1 (45.4)
1.7:1 (37.0)
2.8:1 (26.3)
2:1 (33.3)
2:1 (33.3)
2:1 (33.3)
2:1 (33.3)
74
79
94
84
85
83
91
82
85
11, PhCOO (94.4)
11, PhCOO (53.0)
11, PhCOO (40.3)
11, PhCOO (35.3)
11, PhCOO (22.8)
10, MeCOO (29.9)
12, PhS (27.7)
15 767
34 436
37 114
43 808
51 576
80 337
95 952
82 763
1.54
1.87
2.24
2.05
1.50
2.47
1.49
1.39
13, CN (30.4)
14, N3 (27.7)c
a The polymers in entries 1-5 correspond to those in Table 1. b The differences in the content of 2 (mol %) in the starting copolymer 7 and Nu (mol %)
in the final copolymer indicate that the bromo substitution is not complete. c Insoluble polymer.
Figure 1. 1H (a) and 13C{1H} (b) NMR spectra of polymer 11 (n = 4; Nu = PhCO2).
conjugated acids (carboxylates and sulfide) or used as salts
(cyanide and azide).14,15
Scheme 3. Synthesis of Polynorbornenes with Pendant Triazole Groups
The extent of substitution was determined by quantitative
analysis of residual halide in the polymer; in general, about
10% of the initial CH2Br groups remain unreacted in the new
polymer. The incorporation of the functional groups was
confirmed spectroscopically. Characteristic IR absorption
bands for the ester, nitrile or azido groups were found
whereas the C-Br absorption at 636 cm-1 was almost absent
(see Experimental Section and Supporting Information).
groups has occurred (Scheme 3). This click reaction gives
access to new polymers with pendant triazoles and illustrates
the versatility of these new polynorbornenes for further
functionalization. Click chemistry has been used successfully
to attach catalysts to commercial polystyrene resins through
a triazole link,16 so the polynorbornenes prepared here are
good candidates for use as a new type of matrix support in
these applications.
1
Moreover, the H and 13C NMR resonances of methylene
group attached to the new functionality showed noticeable
different chemical shifts compared to the parent -CH2Br
group. Figure 1 shows the 1H and 13C{1H} NMR for the ben-
zoate substituted polymer 11 (n = 4) resulting from ester
substitution in 9, where the chemical shift of the -CH2Br
methylene signal is 3.4 ppm.
Starting from bromoalkyl polynorbornenes with different
composition, these substitution reactions provide new poly-
norbornenes with variable content of the polar groups, as
exemplified for the benzoate derivatives (entries 1-5, Table 2).
This method gives access to substituted polynorbornenes that
cannot be prepared by vinylic addition polymerization of the
corresponding monomers. For instance, it has been reported
that the polymer with cyano groups 13 (entry 8, Table 2) could
not be synthesized by vinylic polymerization or copolymeriza-
tion of norbornylene nitrile because the presence of a cyano
group deactivated the Ni catalysts that had been useful for the
polymerization of other substituted norbornenes.6d
Conclusion
New vinylic addition functionalized polynorbornenes with
polar groups can be achieved by a different route starting from
haloalkyl polynorbornenes that circumvents the problems com-
monly encountered in attempted homo or copolymerization of
norbornene with some functionalized monomers. The new halo-
alkyl polynorbornenes reported here open a way to cover a broad
composition range, both in the nature of the pendant function-
ality and in its concentration in the final polymer.
Experimental Section
Interestingly the reaction of the azido derivative Copol-
NB-NBCH2N3 (14) with alkynes leads to new polynorbornenes
where complete transformation of the azido groups to triazole
Materials and General Considerations. NMR spectra were
recorded at 298 K using Bruker AC-300, ARX-300 and AV-400

Article
Macromolecules, Vol. 43, No. 18, 2010 7485
instruments. Chemical shifts (δ) are reported in ppm and refer-
enced to SiMe4 (1H and 13C) and CFCl3 (19F). The solid state
NMR spectra were recorded at room temperature under magic
angle spinning (MAS) in a Bruker AV-400 spectrometer using a
Bruker BL-4 probe with 4 mm diameter zirconia rotors spinning
at 10 kHz. The halogen content in the polymers was determined
by oxygen-flask combustion of a sample and analysis of the
residue by mercurimetric titration of the chloride.17 Size exclu-
sion chromatography (SEC) was carried out using a Waters SEC
system on a three-column bed (Styragel 7.8ꢀ300 mm columns:
50-100 000, 5000-500 000 and 2000-4 000 000 Da) and a
Waters 410 differential refractometer. SEC samples were run
in CHCl3 at 313 K and calibrated to polystyrene standards.
Solvents were dried using a Solvent Purification System (SPS).
Norbornene, dicyclopentadiene, benzoic acid, DBU, tetrabutyl-
ammonium cyanide, sodium azide, dimethylacetylenedicarbox-
ylate, thiophenol, and the organic halides were purchased from
Aldrich, Acros, Merck, or Lancaster. The compound [Ni(C6F5)2-
(SbPh3)2] was prepared according to the literature.8,18
Synthesis of Haloalkyl Norbornenes. Synthesis of 4. A mix-
ture of 6-bromo-1-hexene (1.56 mL, 11.66 mmol) and dicyclopen-
tadiene (0.78 mL, 5.83 mmol) is heated at 200 °C for 72 h. The
resulting mixture is distilled under reduced pressure (180 °C, 0.6
mmHg) to obtain a colorless liquid, 4, which is a 83:17 endo:exo
mixture of isomers (0.710 g, 27% yield). MS (EI, m/z (%)): 230 (1)
[Mþ], 228 (1) [Mþ], 149 (1) [Mþ - Br], 93 (2) [Mþ - (CH2)4Br],
79 (5) [Mþ - NB(CH2)4], 66 (100) [Mþ - CH2CH(CH2)4Br].
1,19 2,20 and 321 were synthesized in the same way, starting
from the corresponding bromo- or chloroalkene.
8 (a/b = 0). 1H NMR (300.13 MHz, δ, CDCl3): 3.4 (br, 2H,
H9), 2.7-0.4 (br, H1-H8). 13C{1H} NMR (75.4 MHz, δ,
CDCl3): 50-41 (br, 2C, C5, C6), 41-38 (br, 3C, C1, C4, C8),
38-34 (br, 1C, C7), 32 (br, 1C, C9), 32-29 (br, 2C, C2, C3). 19
F
NMR (282 MHz, δ, CDCl3): -162.9 (Fmeta), -157.1 (Fpara),
-139.6, -135.2 (Fortho). IR (KBr, cm-1), υ(C-Br): 566 (m). The
polymer contains 327.01 mg of Br/g of Cop.
9 (a/b=0). 1H NMR (300.13 MHz, δ, CDCl3): 3.4 (br, 2H, H11)
2.9-0.4 (br, H1-H10). 13C{1H} NMR (75.4 MHz, δ, CDCl3):
52-35 (br, 4C, C1, C4, C5, C6), 34 (br, 2C, C8, C11), 34-32 (br, 1C,
C7),33 (br, 1C, C10) 32-28 (br, 2C, C2, C3), 27 (br, 1C, C9). 19
F
NMR (282 MHz, δ, CDCl3): -163.4 (Fmeta), -158.3 (Fpara),
-139.2, -135.2 (Fortho). IR (KBr, cm-1), υ(C-Br): 562 (m).
The polymer contains 306.10 mg of Br/g of Cop.
Copolymerization Reactions. Copolymerization of Norbornene
and 2. Bromomethylnorbornene (0.5000 g, 2.670 mmol) and 0.67 mL
of a solution of NB in CH2Cl2 (4 M, 2.670 mmol) are mixed under a
nitrogen atmosphere.22 Asolutionof[Ni(C6F5)2(SbPh3)2] (0.0391 g,
0.035 mmol) in dry CH2Cl2 (5.0 mL) was added dropwise to the
former mixture. The starting yellow solution gets darker and the
viscosity increases gradually. The mixture is stirred for 24 h at room
temperature and then poured onto MeOH (30 mL). A solid preci-
pitates which was stirred for 30 min, filtered, washed with MeOH
(2ꢀ5 mL) and air-dried. The copolymer is obtained as a white solid
(0.5522 g, 74% yield).
7 (a/b = 1.7). 1H NMR (300.13 MHz, δ, CDCl3): 3.4 (br, 2H,
H8), 2.7-0.4 (br, H1-H7). 13C NMR (75.4 MHz, δ, CDCl3):
52-48 and 48-45 (br, 2C, C5, C6), 45-38 (br, 2C, C1, C4), 37
(br, 1C, C8), 38-34 (br, 1C, C7), 31-28 (br, 2C, C2, C3). 19F NMR
(282 MHz, δ, CDCl3): -163.4 (Fmeta), -158.6, -157.8 (Fpara),
-140.5, -140.1, -135.5, -133.9 (Fortho). IR (KBr, cm-1),
υ(C-Br): 639 (m). The copolymer contains 230.97 mgBr/gCop,
which corresponds to a NB:2=1.7:1 ratio.
The copolymerization reactions using a different monomer
feed ratio or different haloalkylnorbornenes (Table 1) were
carried out in the same way.
1
endo-4. H NMR (300.13 MHz, δ, CDCl3): 6.09 (dd, 1H,
H5), 5.90 (dd, 1H, H6), 3.39 (t, 2H, H11), 2.74 (br, 2H, H1, H4),
1.96 (m, 1H, H2), 1.82 (m, 3H, H3, H10), 1.38 (m, 3H, H7, H9),
6 (a/b = 1.6). 1H NMR (300.13 MHz, δ, CDCl3): 3.4 (br, 2H,
H8), 2.9-0.2 (br, H1-H7). 13C NMR (75.4 MHz, δ, CDCl3):
55-45 (br, 2C, C5, C6), 48 (br, 1C, C8), 44-38 (br, 2C, C1, C4),
36-34 (br, 1C, C7), 31-29 (br, 2C, C2, C3). 19FNMR(282MHz, δ,
CDCl3): -163.1 (Fmeta), -157.6 (Fpara), -139.6, -134.8 (Fortho).
IR (KBr, cm-1), υ(C-Cl): 718 (m). The copolymer contains 121.81
mg of Cl/g of Cop, which corresponds to a NB:1=1.6:1 ratio.
8 (a/b = 1.3). 1H NMR (300.13 MHz, δ, CDCl3): 3.4 (br, 2H,
H9), 2.7-0.3 (br, H1-H8). 13C NMR (75.4 MHz, δ, CDCl3):
55-49 and 49-45 (br, 2C, C5, C6), 45-39 (br, 2C, C1, C4),
41-39 (br, 1C, C8), 39-34 (br, 1C, C7), 34-31 (br, 1C, C9),
31-29 (br, 2C, C2, C3). 19F NMR (282 MHz, δ, CDCl3): -162.9
(Fmeta), -157.5 (Fpara), -139.3, -134.1 (Fortho). IR (KBr, cm-1),
υ(C-Br): 569 (m). The copolymer contains 243.36 mg of Br/g of
Cop, which corresponds to a NB:3=1.3:1 ratio.
0
0
1.20 (d, 1H, H7 ), 1.07 (m, 2H, H8), 0.47 (ddd, 1H, H3 ). 13C{1H}
NMR (75.4 MHz, δ, CDCl3): 137.02 (s, 1C, C5), 132.21 (s, 1C,
C6), 49.55 (s, 1C, C7), 45.32 and 42,50 (s, 2C, C1, C4), 38.56 (s,
1C, C2), 33.93 and 33.82 (s, 2C, C8, C11), 32.99 (s, 1C, C10), 31.58
(s,1C, C3), 27.15 (s,1C, C9).
exo-4. H NMR (300.13 MHz, δ, CDCl3): 6.06 (dd, 1H, H6),
1
6.00 (dd, 1H, H5), 2.50 (br, 1H, H1). 13C{1H} NMR (75.4 MHz, δ,
CDCl3): 136.76 (s, 1C, C6), 136.20 (s, 1C, C5), 46.27 (s, 1C, C1)
[Most signals are overlapped by the resonances of the endo isomer.]
Homopolymerization Reactions. Homopolymerization of 2.
A solution of [Ni(C6F5)2(SbPh3)2] (0.0391 g, 0.035 mmol) in dry
CH2Cl2 (5.9 mL) is added dropwise to bromomethylnorbornene
(0.5000 g, 2.670 mmol). The starting yellow solution gets darker
and the viscosity increases gradually. The mixture is stirred for
24 h at room temperature and then poured onto MeOH (30 mL).
A solid precipitated which was stirred for 30 min, filtered,
washed with MeOH (2ꢀ5 mL) and air-dried. The homopolymer
is obtained as a white solid (0.2520 g, 50% yield).
9 (a/b = 1.4): 1H NMR (300.13 MHz, δ, CDCl3): 3.4 (br, 2H,
H11), 2.8-0.4 (br, H1-H10). 13C NMR (75.4 MHz, δ, CDCl3):
55-50 and 50-46 (br, 2C, C5, C6), 46-38 (br, 2C, C1, C4), 38-35
(br, 1C, C7), 35-33 (br, 2C, C8, C11), 33-32 (br, 1C, C10), 33-28
(br, 2C, C2, C3), 28-27 (br, 1C, C9). 19F NMR (282 MHz, δ,
CDCl3): -162.9 (Fmeta), -158.1 (Fpara), -140.0 (Fortho). IR (KBr,
cm-1), υ(C-Br): 562 (m). The copolymer contains 219.06 mg of
Br/g of Cop, which corresponds to a NB:4=1.4:1 ratio.
7 (a/b=0). 1H NMR (300.13 MHz, δ, CDCl3): 3.4 (br, 2H, H8)
2.8-0.4 (br, H1-H7). 13C{1H} NMR (75.4 MHz, δ, CDCl3):
52-39 (br, 4C, C1, C4, C5, C6), 39-31 (br, 4C, C2, C3, C7, C8). 19
F
NMR (282 MHz, δ, CDCl3): -162.7 (Fmeta), -157.0 (Fpara),
-139.7, -135.9 (Fortho). IR (KBr, cm-1), υ(C-Br): 634(m). The
polymer contains 399.48 mg of Br/g of Cop.
Functionalization of Polynorbornenes. Synthesis of Copol-
NB-NB(CH2)nOCOPh (11). Cop-NBNBCH2Br of composi-
tion NB:2=1.95:1 (0.2000 g, 0.540 Br equiv), toluene (10 mL),
benzoic acid (0.1662 g, 1.350 mmol), and DBU (0.20 mL, 1.350
mmol) were mixed in a flask. The mixture was refluxed for 11 h.
The solvent was evaporated to ca. 2 mL and MeOH was added
(50 mL). A solid appeared, which was stirred for 30 min, filtered,
washed with MeOH (2 ꢀ 10 mL), and air-dried. The product is
obtained as a white solid (0.1884 g, 84% yield).
The homopolymerization reactions of 1, 3, and 4 were carried
out in the same way.
6 (a/b=0). 1H NMR (300.13 MHz, δ, CDCl3): 3.4 (br, 2H, H8)
2.9-0.4 (br, H1-H7). 13C{1H} NMR (75.4 MHz, δ, CDCl3):
51-45 (br, 2C, C5, C6), 47 (br, 1C, C8), 45-40 (br, 2C, C1, C4),
40-35 (br, 1C, C7), 35-30 (br, 2C, C2, C3). 19FNMR(282MHz, δ,
CDCl3): -162.3 (Fmeta), -156.7 (Fpara), -139.4, -135.5 (Fortho).
IR (KBr, cm-1), υ(C-Cl): 722 (m). The polymer contains 212.61
mg of Cl/g of Cop.
1
11 (n = 1). H NMR (300.13 MHz, δ, CDCl3): 8.0 (br, 2H,
Hortho Ph), 7.5 (br, 1H, Hpara Ph), 7.4 (br, 2H, Hmeta Ph), 4.3 (br,

7486 Macromolecules, Vol. 43, No. 18, 2010
Martınez-Arranz et al.
2H, H8), 2.9-0.4 (br, H1-H7). 13C NMR (75.4 MHz, δ, CDCl3):
167.0 (br, 1C, OCOR), 132.8 (br, 1C, Cpara Ph), 130.5 (br, 1C,
Cipso Ph), 129.5 (br, 2C, Cortho Ph), 128.3 (br, 2C, Cmeta Ph),
68-65 (br, 1C, C8), 50-46 (br, 2C, C5, C6), 44-38 (br, 2C, C1,
C4), 38-35 (br, 1C, C7), 33-29 (br, 2C, C2, C3). IR (KBr, cm-1),
υ(CdO): 1720 (s); υ(C-O): 1270 (s). The copolymer contains 9.7
mg of Br/g of Cop, which indicates 95% of Br substitution.
Copol-NBNB(CH2)2OCOPh, Copol-NBNB(CH2)4OCOPh
were synthesized in the same way. Copol-NBNBCH2OCOMe
was prepared following the same method but using acetic acid
instead of benzoic acid.
is treated with NaN3 (0.2106 g, 3.240 mmol) in DMF (10 mL) at
120 °C for 24 h. The solid is filtered and washed with DMF (2 ꢀ
5 mL), water (2ꢀ 5 mL) and finally with MeOH (2 ꢀ 5 mL). The
product is obtained as a white solid (0.1547 g, 85% yield), insoluble
in common solvents.
IR (KBr, cm-1), υ(N3): 2092 (s). 13C CP-MAS NMR (100.61
MHz): 63-21 (br, 8C). The copolymer contains 35.92 mg of Br/g
of Cop, which indicates 85% of Br substitution.
Synthesis of Copol-NB-NBCH2triazole (15). A mixture of
Cop-NBNBCH2N3 (0.1135 g, 0.330 equiv of N3), toluene (5 mL),
and dimethyl acetylenedicarboxylate (0.12 mL, 1.000 mmol)
was refluxed for 7 h. After this time, MeOH (40 mL) was added
and the solid was stirred for 30 min, filtered off, washed with
MeOH (2ꢀ10 mL), and air-dried. The product is obtained as a
yellowish solid (0.1171 g, 85% yield) insoluble in common
solvents.
11 (n=2). 1H NMR (300.13 MHz, δ, CDCl3): 8.0 (br, 2H, Hortho
Ph), 7.5 (br, 1H, Hpara Ph), 7.4 (br, 2H, Hmeta Ph), 4.3 (br, 2H, H9),
2.8-0.4 (br, H1-H8). 13C NMR (75.4 MHz, δ, CDCl3):166.6 (br,
1C, OCOR), 132.7 (br, 1C, Cpara Ph), 130.5 (br, 1C, Cipso Ph), 129.5
(br, 2C, Cortho Ph), 128.3 (br, 2C, Cmeta Ph), 66-63 (br, 1C, C9),
55-51 and 51-45 (br, 2C, C5, C6), 45-38 (br, 2C, C1, C4), 40-38
(br, 1C, C8), 38-34 (br, 1C, C7), 34-28 (br, 2C, C2, C3). IR (KBr,
cm-1), υ(CdO): 1719 (s); υ(C-O): 1273 (s). The copolymer con-
tains 5.8 mg of Br/g of Cop, which indicates 97% of Br substitution.
IR (KBr, cm-1), υ(CdO): 1735 (s); υ(C-O): 1225 (s). 13C
CP-MAS NMR (100.61 MHz): 160 (br, 2C, OCOR), 140 (br,
1C, CdC), 130 (br, 1C, CdC), 63-22 (br, 10 C).
Determination of Reactivity Ratios. Reactivity ratios for the
copolymerization of NB/2 were determined by fitting the data of
entries 2-5 in Table 1 to the Finemann-Ross equation.23
Copolymerization reactions of NB and 3 or 4 were carried out
using the same monomer feed ratios and conditions of entries
2-4 in Table 1. Reactivity ratios were estimated using the same
procedure followed for 2.
1
11 (n = 4). H NMR (300.13 MHz, δ, CDCl3): 8.0 (br, 2H,
H
ortho Ph), 7.5 (br, 1H, Hpara Ph), 7.4 (br, 2H, Hmeta Ph), 4.3 (br,
2H, H11), 2.6-0.4 (br, H1-H10). 13C NMR (75.4 MHz, δ,
CDCl3): 166.6 (br, 1C, OCOR), 132.7 (br, 1C, Cpara Ph), 130.5
(br, 1C, Cipso Ph), 129.5 (br, 2C, Cortho Ph), 128.3 (br, 2C, Cmeta
Ph), 65.1 (br, 1C, C11), 55-49 and 49-44 (br, 2C, C5, C6), 44-38
(br, 2C, C1, C4), 38-34 (br, 1C, C7), 33-28 (br, 3C, C2, C3, C8),
29 (br, 1C, C10), 25 (br, 1C, C9). IR (KBr, cm-1), υ(CdO): 1717
(s); υ(C-O): 1272 (s). The copolymer contains 5.2 mg of Br/g of
Cop, which indicates 96% of Br substitution.
Acknowledgment. Financial support is gratefully acknow-
ledged from the Spanish MEC (DGI, Grant CTQ2007-67411/
BQU; Consolider Ingenio 2010, Grant INTECAT, CSD2006-
10 (n=1). 1H NMR (300.13 MHz, δ, CDCl3): 4.0 (br, 2H, H8),
2.9-0.4 (br, H1-H7, CH3). 13CNMR(75.4MHz, δ, CDCl3): 172.0
(br, 1C, OCOR), 69-66 (br, 1C, C8), 54-50 and 50-46 (br, 2C, C5,
C6), 44-38 (br, 2C, C1, C4), 38-35 (br, 1C, C7), 33-29 (br, 2C, C2,
C3), 21 (br, 1C, CH3). IR (KBr, cm-1), υ(CdO): 1744 (s); υ(C-O):
1240 (s). The copolymer contains 9.9 mg of Br/g of Cop, which
indicates 96% of Br substitution.
Synthesis of Copol-NB-NBCH2SPh (12). To a stirred mix-
ture of DBU (0.16 mL, 1.080 mmol) and tiophenol (0.12 mL,
1.080 mmol) in toluene (10 mL) was added a solution of
Cop-NBNBCH2Br of composition NB:2 = 1.95:1 (0.2000 g,
0.540 Br equiv) in toluene (10 mL). The solution was refluxed for
13 h, and then MeOH (50 mL) was added. After the reaction was
stirred for 30 min, the white solid was filtered off, washed with
MeOH (2ꢀ10 mL), and air-dried. The polymer was obtained as
a white solid (0.1972 g, 91% yield).
0003), and the Junta de Castilla y Leon (Grupo de Excelencia
ꢀ
GR169). We also thank Teresa Blasco and AlejandroVidal (ITQ,
ꢀ
Universidad PolitecnicadeValencia-CSIC) for their help withthe
determination of CPMAS spectra.
Supporting Information Available: Figures showing 1H and
13C NMR spectra of the polymers prepared as well as IR
spectra. This material is available free of charge via the Internet
at http://pubs.acs.org.
References and Notes
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(2) Some recent patents: (a) Amoroso, D.; Bedwell, B.; Bell, A.; Elce,
E.; Gan, D.; Kang, S. H.; Makabe, H.; Puthenkovilakom, R. R.;
Ravikiran, R.; Shick, R.; Takahashi, Y.; Takeuchi, E.; Wu, X.
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1H NMR (300.13 MHz, δ, CD2Cl2): 7.1-7.4 (br, 5H, H Ph)
3.4-2.6 (br, 2H, H8), 2.6-0.4 (br, H1-H7). 13C NMR (75.4
MHz, δ, CDCl3): 137.3 (br, 1C, Cipso Ph), 128.5 (br, 4C, Cortho
Ph, Cmeta Ph), 125.6 (br, 1C, Cpara Ph), 55-46 (br, 2C, C5, C6),
46-39 (br, 2C, C1, C4), 41-36 (br, 1C, C8), 36-34 (br, 1C, C7),
34-28 (br, 2C, C2, C3). The copolymer contains 33.5 mg of Br/g
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Synthesis of Copol-NB-NBCH2CN (13). To a solution of
tetrabutylammonium cyanide (0.2175 g, 0.810 mmol) in THF
(10 mL) is added Cop-NBNBCH2Br of composition NB:2 =
1.95:1 (0.2000 g, 0.540 Br equiv) in THF (10 mL). The solution is
refluxed for 9 h. The solvent was evaporated to ca. 2 mL and
then MeOH was added (50 mL). The mixture was stirred for
30 min and then the solid copolymer was filtered, washed with
MeOH (2ꢀ10 mL) and air-dried. The product is obtained as a
yellow solid (0.2127 g, 82% yield).
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1H NMR (300.13 MHz, δ, CDCl3): 2.9-0.4 (br, H1-H8). 13
C
NMR (75.4 MHz, δ, CDCl3): 120 (br, 1C, CN), 55-50 and
50-46 (br, 2C, C5, C6), 44-38 (br, 2C, C1, C4), 38-35 (br, 1C,
C7), 33-29 (br, 2C, C2, C3), 20.0 (br, 1C, C8). IR (KBr, cm-1),
υ(CN): 2247 (w). The copolymer contains 21.1 mg of Br/g of
Cop, which indicates 92% of Br substitution.
Synthesis of Copol-NB-NBCH2N3 (14). Cop-NBNBCH2Br
of composition NB:2 = 1.95:1 (0.2000 g, 0.540 Br equivalents)

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