Synthesis and characterization of homopolymers and copolymers containing closo-[B12H12]2- boron cage derivatives

Article abstract of DOI:10.1002/chem.200801430

New [B₁₂H₁₂]^2- boron cage functionalized neutral and ionic methacrylate and styrene monomers (1, 2, 3) were synthesized and these monomers were used to prepare homopolymers (4, 5, 6) and copolymers with methylmethacrylate

Full text of DOI:10.1002/chem.200801430

DOI: 10.1002/chem.200801430
Synthesis and Characterization of Homopolymers and Copolymers
Containing closo-[B12H12]2À Boron Cage Derivatives
Teshome B. Yisgedu,[a] Xuenian Chen,[a] Scott Schricker,*[b] Jon Parquette,*[a]
Edward A. Meyers,[a] and Sheldon G. Shore*[a]
Abstract: New [B12H12]2À boron cage
functionalized neutral and ionic meth-
ACHTUNGTRENNUNGacrylate and styrene monomers (1, 2,
3) were synthesized and these mono-
mers were used to prepare homopoly-
mers (4, 5, 6) and copolymers with
methylmethacrylate (MMA) (7, 8), 2-
polymers and they were characterized
by 1H NMR, 11B NMR, and IR spec-
troscopy, differential scanning calorim-
etry (DSC), thermogravimetric analysis
(TGA), and gel permeation chroma-
tography (GPC). Generally, the poly-
mers show broad 1H NMR and
11B NMR peaks compared to their re-
spective monomers. The copolymers
have high molecular weights with
higher [B12H12]2À boron cage mole
ratios. All the polymers on which DSC
experiments were conducted (4b, 5b,
6b, 7, 8, 9, 10, 17, 18, and 19) are non-
glassy amorphous solids, except styrene
copolymers (9, 19) and homopolymer
(6b) which show Tg values of 100, 117,
and 1628C, respectively. Copolymers 9
and 10 have higher thermal stability
(3208C) than polymers 5b, 4b, and 8,
which are stable up to 244, 250, and
2608C, respectively. The homopolymers
retained more weight than the copoly-
mers when they were heated to 4008C.
hydroxy
G
(HEMA)
(11, 12, 13, 17), 2-hydroxyethylacrylate
(HEA) (14, 15, 18), acrylamide (AA)
(16), and styrene (9, 10, 19) with differ-
ent monomer ratios. Free-radical initi-
ated bulk and solution polymerization
methods were used to synthesize these
Keywords: boron · dodecahydrobo-
rate · inorganic polymers · polymers
Introduction
phy (EUV) to improve oxygen etch resistance to the EUV
material.[7] A number of siloxane-based carborane-contain-
ing polymers have been studied[15] because the polymers
maintain elastomeric properties while gaining thermal stabil-
ity from the carborane. Keller and co-workers[3c,16b,c] have
prepared a series of these polymers (siloxane-acetylene-car-
Interest in polymers containing boron cage compounds
(C2B10H12 (carboranes), [B10H10]2À, [B12H12]2À) derives from
their stability towards acids/bases and their very high ther-
mal stability.[1] These polymers have potential applications
as neutron shields,[2] pre-ceramic materials (heat shield),[3]
microwave-absorbing materials,[4] cation exchangers,[5] and
in boron neutron capture therapy (BNCT).[6] A carborane
carboxylic acid copolymer was used in extreme UV lithogra-
borane) in different ratios. It was found that a siloxyl-di
ACHTUNGTRENNUNGacet-
AHCTUNGTREGyNNNU lene-ferrocenylene-carboranyl polymer is converted to a
thermoset at 3508C, and it converts to a ferromagnetic ce-
ramic material upon heating to 10008C.[16k] The same group
have reported that a cured siloxane-diacetylene-carborane
polymer showed a very high oxidative stability up to
10008C. Most of the boron-cage containing polymers report-
ed so far are derived from a carborane unit.
For economic reasons, carborane-containing polymers
have not been widely applicable. Different polymerization
methods have been used to make these carborane-contain-
ing polymers. Condensation, anionic, cationic, radical, graf-
ting,[4b] plasma[8] polymerizations methods have been ap-
plied. Carborane-cage-containing polyesters,[9] polyamides,[10]
polyacrylates,[11] polyepoxides,[12] polyetherketones,[13] poly-
styrenes,[14] polysiloxanes,[15] polyurethanes,[16] polyureas,[17]
polyhydrazides,[18] polyoxadiazoles,[19] polyalkenes,[20] and
polyalkynes[21] have been reported. These polymers were
[a] Dr. T. B. Yisgedu, Dr. X. Chen, Prof. J. Parquette, Dr. E. A. Meyers,
Prof. S. G. Shore
The Ohio State University
Columbus, Ohio 43210 (USA)
Fax : (+1)614-292-1685
E-mail: parquette.1@ohio-state.edu
shore.1@ohio-state.edu
[b] Prof. S. Schricker
School of Dentistry
The Ohio State university
Columbus, Ohio 43210 (USA)
Fax : (+1)614-292-9422
E-mail: schricker.1@osu.edu
Supporting information for this article is available on the WWW
under http://dx.doi.org/10.1002/chem.200801430.
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Chem. Eur. J. 2009, 15, 2190 – 2199

FULL PAPER
prepared by homopolymerization of the carborane mono-
mer or copolymerization of carborane with non-carborane
monomers or copolymerization of different functional
groups of carborane monomers. Recently, oligomers of car-
borane made by gaseous ionization of o-carborane to form
four o-carborane-containing clusters have been reported.[22]
Herein, we present a new form of boron-cage-containing
polymers prepared from a dimethyl sulfide derivative of the
closo-[B12H12]2À cage.[23] An advantage of dimethyl sulfide
derivatives of closo-[B12H12]2À over carboranes is that the
cage compound closo-[1,7-{(CH3)2S}2B12H10] is prepared
from the borane dimethyl sulfide complex (BH3Me2S) in
one step and in good yield. Preparation of carboranes in-
volves multistep procedures and their commercially avail-
able precursor (decaborane) is expensive. We have prepared
one new closo-[B12H12]2À cage containing methacrylate ([(1-
MeSCH2CH2OC(O)C(Me)=CH2)-7-(Me2S)B12H10]) and two
new styrene ([(1-(MeS-CH2-Ph-CH=CH2)-7-(Me2S)B12H10]
and [NBu4][1-(MeS-CH2-Ph-CH=CH2)B12H11] (3)) deriva-
tives of the closo-[B12H12]2À cage. We employed these mono-
mers to synthesize homopolymers and copolymers. The co-
polymerization was carried out with methylmethacrylate
(MMA), 2-hydroxyethylmethacrylate (HEMA), 2-hydroxy-
chloride in dichloromethane in the presence of triethylamine
(Scheme 1). The white powder was unstable at room tem-
perature. In fact, after chromatographic separation (after
the polymerization inhibitor 2,6-di-tert-butyl-4-methylphenol
(BHT) was added), the white powder turned to yellow when
it was left at room temperature overnight. The color change
is most likely due to air oxidation of the fine powder instead
of polymerization. This color change was prevented by crys-
tallizing the white powder right after chromatography and
storing it in a refrigerator at 48C. Styrene monomer 2 and
ionic styrene monomers 3a/3b were prepared by the nucleo-
philic
substitution
reaction
of
[NMe4][1-
ACHTUNGTRENNUNG
(Me2S)B12H10] and [(NBu4]2[1-
N
U
(MeS)B12H11] with 4-vinylbenzyl chloride, respectively
(Scheme 1). Monomers 1 and 2 were characterized by
1H NMR, 11B NMR, 13C NMR, and IR spectroscopy, as well
as MS-EI and single-crystal X-ray crystallography. Monomer
1
3a was characterized by H NMR, 11B NMR, and IR spec-
troscopy, as well as MS-ESI, and 3b was characterized by
1
single-crystal X-ray crystallography in addition to H NMR,
11B NMR, and IR spectroscopy as well as MS-ESI. The
methylene protons next to the sulfur are diastereotopic as
evidenced from the 1H NMR spectrum, which shows two
separate multiplets at d=3.10/3.43 ppm (for 1) and d=3.83/
4.34 ppm (for 2 and 3). A single crystal of 1 suitable for X-
ray crystallography was obtained by diffusion of hexane sol-
vent into dichloromethane solutions of 1. The crystal is tri-
ACHTUNGTRENNUNGethylacrylate (HEA), acrylamide (AA), and styrene (St).
Results and Discussion
¯
clinic, space group P1. In 1, there is only one type of inde-
Alkylation of prochiral methylthioethers [NMe4]2[1-
pendent molecule (one enantiomer) in the unit cell. Thus
the two enantiomers crystallized in different unit cells giving
a mixture of racemates of 1. The two methyl groups on S2
are disordered and their geometry as shown in the molecu-
lar structure is approximate (Figure 1).
MeSB12H11] and [NMe4][1-ACTHNURGTNEUNG(MeS)-7-(Me2S)B12H10] yields a
racemic mixture.[24] The precursor to monomer 1 ([1-
MeSCH2CH2OH)-7-(Me2S)B12H10]) (Scheme 1) was synthe-
sized by the nucleophilic substitution reaction of [NMe4][1-AHCTUNG-
T
Single crystals for 2 were obtained in the same way as
those of 1 (diffusion of hexane solvent into dichloromethane
solutions of 2). The crystal is triclinic, space group P1. The
the method of Shore and co-workers.[25] Methacrylate mono-
mer 1 was prepared by the esterification of the alcohol ([1-
(MeSCH2-CH2OH)-7-(Me2S)-B12H10]) with methacryolyl-
¯
unit cell of 2 contains two independent racemic enantiomers.
Unlike 1, the racemates of 2
crystallize in the same unit cell
(Figure 2). Crystallization was
unsuccessful when using tetra-
butylammonium as the cation
of 3a. To obtain a single crys-
tal, the tetrabutylammonium
cation was replaced by triphe-
nylmethylphosphonium cation.
Monomer 3b was obtained
from reaction
the
of
[(PPh3Me)]2[1-CAHTUNGTRENN(UNG MeS))B12H11]
with 4-vinylbenzyl chloride,
which initially formed the tri-
phenylmethylphosphonium salt
of 3a (Figure 3). Colorless crys-
tals of 3b were obtained by dif-
fusion of toluene into a di-
chloromethane solution of 3b.
There is only one type of inde-
Scheme 1. Synthesis of monomers 1, 2, and 3.
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2191

S. Stricker, J. Parquette, S. G. Shore et al.
Figure 1. ORTEP plot of the molecular structure of 1 (25% thermal el-
lipsoids).
Figure 3. ORTEP plot of the molecular structure of the anionic part 3
(25% thermal ellipsoids).
pendent molecule (enantiomer)
in the unit cell of 3b and like
monomer 1, 3b crystallizes as a
mixture of racemates. The
methacrylate unit on 1 forms
approximately 3/4 of a circle
parallel to B1–B12 axis starting
from C7 (on S1) to C2
B12 cage containing monomers (1 or 2) with MMA, HEMA,
AA, and styrene monomers were performed by bulk (when-
ever the B12 monomer can dissolve in the low molecular
weight monomers) or solution polymerization (where both
B12 and small molecular weight monomers can dissolve in a
suitable solvent; Scheme 2). The molecular weights of the
polymers are given in Table 1.
À
(Figure 1). The B B bond
lengths in 1 range from 1.753(5)
to 1.816(5) ꢁ. The vinyl bond
(CH2=C) of 1 was differentiated
Homopolymers 4a, 5a, and 6a were synthesized by radi-
cal-initiated polymerization of 1 and 2 in toluene, and 3 in
2-methyl-THF, respectively. Polymers 4a and 5a formed
solid materials and were isolated by filtration, whereas 6a
stuck to the glass vessel as a gel. After the solvent was
À
from the single bond (CH3 C)
by its shorter bond length
1
À
(1.325(5) ꢁ
((CH3 C)=
evaporated, it was scraped from the glass. The H NMR or
1.472 ꢁ)). The X-ray crystal
structure (Figure 2) of 2 shows
the vinyl benzyl group pointing
away from the B12 cage (paral-
lel to B1–B12 axis). Selected
bond lengths and angles for 1,
2, and 3b are given in Table S2
in the Supporting Information.
The bond lengths of the vinyl
double bond in 2 and 3b are
ACTHNGUTERNNUG
1H{11B} NMR spectra are provided in the Results and Dis-
cussion section of the Supporting Information. The
11B NMR resonances of 4a/4b at d=À10.5 ppm (B1 and
B7) and the three boron resonances that are centered at
À15 ppm (B2–B6, B8–B12) (Figure 4) for monomer 1 are
not observed for polymer 4a/4b due to signal broadening.
The same types of homopolymers (4b, 5b, 6b) were synthe-
sized at 648C in THF, and resulted in smaller molecular
weight distributions (PDI 1.27, 2.69, 2.45, respectively). An
oily polymer material started to come out of the solution
after 1 h for 4b and 5b, whereas the polymer 6b comes out
of the solution after 3 h. The proton NMR spectra of 4b,
5b, and 6b are the same as 4a, 5a, and 6a except for a
slight change in the chemical shifts attributed to NMR sol-
vent differences. From the GPC chromatograms, 4b and 6b
show a bimodal distribution (see the Supporting Informa-
tion), and homopolymer 5b shows two peaks clustered to-
gether. The reason 5b shows closely clustered peaks in the
light scattering peak compared to 4b and 6b might be due
to the fact that it is less polar than 4b and 6b (4b has polar
methacrylic groups and 6b has a polar cationic tetrabutyl-
Figure 2. ORTEP plot of the
molecular structure of 2 (25%
thermal ellipsoids).
1.312(4) and 1.305(7) ꢁ, respectively, which are shorter than
the vinyl bond length in the methacrylate monomer 1
(1.325(5) ꢁ). The B B bond lengths range from 1.744(4) to
1.812(4) ꢁ in 2 and from 1.754(6) to 1.802(6) in 3. Unlike 2,
the molecular structure of 3b (Figure 3) reveals that the vi-
nylstyrene group is bent (perpendicular to the B1–B12 axis).
Structural data including bond length and bond angle tables
are available in the Supporting Information. The unit cell of
3 contains two disordered toluene molecules (see the Sup-
porting Information).
À
All polymerizations employed AIBN (2,2’-azo-bis(isobu-
tyronitrile) as a radical initiator. Copolymerization of the
AHCTUNGTREGaNNUN mmonium group).
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Homopolymers and Copolymers Containing closo-[B12H12]2À Boron Cages
FULL PAPER
The reason why the S-
CH2CH2O proton signals in 9
and 10 were not observed
might be due to the formation
of micelles. But when 1 is re-
placed with 2 as shown in the
1H NMR spectrum (Figure 7) of
polymer 19, the diastereotopic
S-CH2 peaks are visible (d=
4.19 and 3.68 ppm).
Copolymers 11, 12, 13, 14,
and 15 were prepared by bulk
and/or solution polymerization
of 1 and non-B12 boron cage
monomers (HEMA, HEA). Po-
lymer 16 was prepared by solu-
tion polymerization of 1 and ac-
rylamide. Results and Discus-
sion for these copolymers are
provided in the Supporting In-
formation.
Differential scanning calo-
rimetry (DSC) of the polymers
(4b, 5b, 6b, 7, 8, 10, 9, 19, and
18) was carried out. From the
DSC experiment, polymers 4b,
5b, 7, 8, 10, and 18 were found
not to melt or undergo a glass
transition up to 2008C. Poly-
mers 5b, 4b, and 8 are stable
Scheme 2. Synthesis of polymers. [a] Bulk polymerization at 1008C. [b] Bulk polymerization at 808C. [c] Poly-
merization in toluene at 1008C. [d] Polymerization in toluene at 808C.
Table 1. Summary of monomers used, solvent, and polymer molecular
weights.
Methacrylate monomer 1 and various mole ratios of
MMA (1:18), MMA (1:2), HEMA (1:3), HEA (1:3) were
polymerized in toluene to form the respective copolymers 8,
17, and 18. After polymerization, the mole ratio of the
Monomer(s), Ratio Solvent
(mol)
Polymer,
Ratio[a]
MN, MW, PDI (GPC
solvent)
1
THF
THF
THF
bulk
4b
90750, 116000, 1.27
(DMF[b]
)
mono
1:2 (17), and 1:3 (18) (from H NMR integration ratios). Co-
ACHTUNGTRENNUNGpolymer 7 is soluble in chloroform and THF. In the proton
ACHTUNGTRENNUNGmers in the polymer was found to be 1:18 (7), 1:1 (8),
2
5b
4260, 11470, 2.69
(DMF[b]
9600, 23600, 2.45
(DMF[b]
1
)
3
6b
)
NMR spectra of 17 and 18 (Figure 5), the hydroxyl group
shifted downfield (4.83 ppm) due to hydrogen bonding with
the polar NMR solvents (DMF or DMSO). The GPC plot
of 17 (Figure 6) shows a bimodal distribution. The IR spec-
tra of these copolymers show the absence of a vinyl stretch-
ing frequency of the acrylate unit and strong bands at 1726
and 2520 cmÀ1, which were assigned to carbonyl and B–H
stretches, respectively.
Three B12-cage-containing styrene copolymers were pre-
pared by bulk polymerization of 1 with styrene (9, 10) or 2
with styrene (19). All three polymer products 9, 10, and 19
form transparent polymer solids. The 1H NMR spectra
(Figure 7) of 9 and 10 show polymerized styrene polymer
peaks (d=6.3–7.5 ppm, ArCH and d=1–1.9 ppm, CH), B–H
protons and thiomethyl protons of 1. The proton signals that
belong to the S-CH2CH2O unit of copolymers 9 and 10 are
not observed. These proton signals were observed when
MMA, HEMA or HEA were used as a co-monomer with 1.
1+MMA, 1:18
1+MMA, 1:2
1+styrene, 1:17
1+styrene, 1:7
7, 1:18
8, 1:1
9, 1:17
10, 1:7
45000, 89000, 1.98
(THF)
toluene
bulk
85300, 346000, 4.06
(DMF[b]
)
12000, 33000, 2.72
(THF)
bulk
165000, 723000, 4.4
(DMF[b]
)
1+HEMA, 1:14
1+HEMA, 1:14
1+HEMA, 1:28
1+HEA, 1:16
1+HEA, 1:16
1+AA, 1:25
toluene
bulk
bulk
bulk
toluene
11
12
13
14
15
partially soluble
insoluble
partially soluble
partially soluble
partially soluble
partially soluble
19050, 48100, 2.52
acetonitrile 16
1+HEMA, 1:3
toluene
toluene
bulk
17, 1:2
(DMF[b]
67720, 561000, 8.3
(DMF[b]
)
1+HEA, 1:3
18, 1:3
)
2+styrene, 1:18
19, 1:18
9342, 34500, 3.69
(THF)
[a] Ratio of monomers in the polymer (mol). [b] 10 mm LiCl in DMF.
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S. Stricker, J. Parquette, S. G. Shore et al.
Figure 4. 11B{1H} NMR spectra of monomer 1 and polymer 4a/4b.
Figure 7. Top: 1H NMR spectrum of 9 in CDCl3; middle 1H NMR spec-
trum of 10 in [D7]DMF; bottom: H NMR spectrum of 19 in CD2Cl2. *=
1
[D7]DMF, **=H2O, @ =CD2Cl2.
up to 244, 250, and 2608C, respectively (see Supporting In-
formation for the DSC thermograms). Polymers 9, 19, and
6b show a glass transition at 100, 117, and 1628C, respec-
tively (Figure 8 and Table 2). The reason the glass transition
increased for 19 and 6b compared with polystyrene or 9 is
that the copolymer is random and the bulky B12 cages stiffen
the polymer chains making it more difficult for the chain to
undergo conformational changes, that is, increased Tg. A de-
tailed discussion on the DSC is provided in the Results and
Discussion section in the Supporting Information.
Thermogravimetric analyses of the polymers were carried
out under an argon atmosphere at a rate of 58C per minute
from room temperature to 4008C. The TGA thermograms
are shown in Figures 9 and 10, and in the Supporting Infor-
mation. The color of the polymers changed from white to
black after the heating phase. Generally, the copolymers
retain less weight percentage than the homopolymers. Even
Figure 5. Top: 1H NMR spectrum of 18 in [D6]DMSO; middle: 1H NMR
spectrum of 17 in [D6]DMSO; bottom: 1H NMR spectrum of
[D7]DMF. *=toluene, @=CH2Cl2, **=DMF, %=H2O.
8 in
Figure 6. GPC curve of 17 showing bimodal distribution (V0 =13.5 mL,
Vt =27.6 mL). There is a 0.5 mL difference in elution volume for the two
detectors.
Figure 8. DSC showing glass transition temperatures for 6b, 19, and 9.
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Homopolymers and Copolymers Containing closo-[B12H12]2À Boron Cages
FULL PAPER
Table 2. Summary of data for DSC and TGA experiments.
ried out (4b, 5b, 6b, 7, 8, 9, 10, 19, 17, and 18) are amor-
phous. The Tg value of the styrene chain polymers (9, 19,
6b) increases as the proportion of B12 cages (1 or 2) increas-
es. The presence of a methacrylate-containing B12 cage
Polymer Monomer,
D[a]
Ratio[b] Tg
[8C]
TD.I
wt%[d] TMD
[8C][e]
[8C][c]
[f]
4b
5b
6b
7
8
9
1, MMA
2, St
3, St
1+MMA
1+ MA
1+St
1:0
1:0
1:0
1:18
1:1
1:17
1:7
1:18
–
–
275
260
–
–
285
–
78
91
–
36
69
45
67
51
275
230
–
297
275
321
323
300
[f]
monoACTHNUTRGNEmNUG er unit (1) in styrene copolymers (10 and 9) in-
162
creased the thermal stability compared to that obtained for
a styrene-containing B12 cage copolymer (19) and homopoly-
mer 5b. However, the thermal stability decreased as the
ratio of methacrylate-containing B12 cage monomer (1) in-
creased in MMA chain polymers (7, 8, and 4b). When
heated to 4008C, the styrenic homopolymer (5b) retains
more weight than the methacrylic homopolymer (4b), and
the copolymers retain less weight than the homopolymers.
[f]
–
–
100
[f]
10
19
1+St
2+St
–
–
–
117
[a] Homopolymer derivatives (styrene or MMA). [b] B12 to non-B12 ratio
in the polymer. [c] Temperature of decomposition isotherm. [d] % weight
retention. [e] Temperature of main chain degradation. [f] No glass transi-
tion observed.
Experimental Section
General methods: All reagents were purchased from Aldrich unless
noted otherwise. 2-Chloroethanol, 4-vinylbenzyl chloride, 2,2’-azo-bis(iso-
butyronitrile) (AIBN), Na2SO4, and acrylamide were used without fur-
ther purification. Monomers methylmethacrylate (MMA), 2-hydroxye-
thylmethacrylate (HEMA), 2-hydroxyethylacrylate (HEA), and styrene
were distilled just before use. DMF was dried from 4 ꢁ molecular sieves,
and acetonitrile and dichloromethane were dried over P2O5. The solvents
toluene, THF, and 2-methyl-THF were dried over sodium/benzophenone
ketyl and transferred over a high vacuum line before use. [NMe4][1-ACHTUNG-
T
ACTHGNURTNE(UNGN MeS)B12H11]/AHCTUNRTGE[GNNUN (PPh3Me4)]2ACHTUNGTRENNUNG[(1-
Figure 9. TGA curves for 4b, 8, and 7.
AHCTUNGTRENNUNG
DMF, respectively.[24] TLC was done on a silica gel thin layer plate, and a
methanol solution of palladium chloride or iodine vapor was used as
stain. All chromatographic separations were performed on a Selecto
silica gel (230–430 mesh), which was purchased from Fisher Scientific. 1H,
13C, and 11B NMR spectra were obtained on a Bruker DPX-250 or DPX-
400 spectrometers at 250.1/400.1 MHz, 62.9/100.6 MHz, and 80.25 MHz
for DPX-250, respectively. Boron spectra were externally referenced to
BF3·OEt2 in C6D6 (d=0 ppm). Molecular weights were determined by
using a Shimadzu 10, a GPC (gel permeation chromatography) system
with a refractive index and light scattering detectors. The molecular
weights and polydispersity indices were determined by importing the text
files of the chromatograms into ASTRA software. First the autobaseline
was done on the chromatograms from both detectors and the respective
peaks were selected. After the amount of sample injected was entered
into the ASTRA software, a report of molecular weights and polydispers-
ity indices was generated. IR spectra were recorded on a Bruker Tensor
27 spectrometer. Mass spectra were recorded on Micromass QTOF elec-
trospray (ESI) or Micromass VG-70 EI spectrometers. Differential scan-
ning calorimetry measurements were performed on DSC Q100 TA in-
strument (Wilmington, DE). Thermogravimetric analyses were per-
formed with a Perkin–Elmer TGA 7 analyzer with a TAC 7/DS thermal
analysis instrument controller, and samples were loaded on a platinum
crucible. Elemental analyses were obtained from Galbraith Laboratories.
Figure 10. TGA curves for 5b and 19.
though the methacrylate homopolymers retain more weight
than the copolymers after heating to 4008C, their main
chain starts to degrade at lower temperature than the co-
polymers with a higher percentage of non-B12 cage (MMA)
monomer units. The TGA data for the polymers is given in
Table 2 and more discussion is provided in the Supporting
Information.
Single-crystal X-ray diffraction data were collected on a Nonius Kappa
CCD diffraction system by using graphite-monochromated MoKa radia-
tion (l=0.71073 ꢁ). A single crystal of 1, 2, and 3b was mounted on the
tip of a glass fiber coated with Fomblin oil (a pentafluoropolyether).
Unit cell parameters were obtained by indexing the peaks in the first ten
frames and were refined by employing the whole data set. All frames
were integrated and corrected for Lorentz and polarization effects using
the DENZO-SMN package (Nonius BV, 1999).[26] Absorption correction
for the structures was accounted for by using SCALEPACK. All non-hy-
drogen atoms were located and refined anisotropically. All hydrogen
atoms connected to boron were located on difference maps and their po-
sitional and isotropic thermal parameters were refined. All other hydro-
gen atom positions were calculated by assuming standard geometries. A
Conclusions
Monomers containing functionalized closo-[B12H12]2À cages
were synthesized and used to synthesize various homopoly-
mers and copolymers. In general, the molecular weight of
the copolymers increases as the proportion of B12 cages in-
creases. The polymers for which DSC experiments were car-
Chem. Eur. J. 2009, 15, 2190 – 2199
ꢀ 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.chemeurj.org
2195

S. Stricker, J. Parquette, S. G. Shore et al.
satisfactory disorder model was not obtained for structure 2 due to a
large peak close to the S1 atom. In structure 3, two seriously disordered
toluene solvent molecules are present in the unit cell (detailed informa-
tion is provided in the Supporting Information). CCDC-696969 (1),
CCDC-696970 (2), and CCDC-696971 (3b) contain the supplementary
crystallographic data for this paper. These data can be obtained free of
charge from The Cambridge Crystallographic Data Centre via
www.ccdc.cam.ac.uk/data_request/cif
Synthesis of [NBu4][1-(MeS-CH2-Ph-CH=CH2) B12H11] (3a): 4-Vinylben-
zyl chloride (0.33 g, 2.16 mmol) was added to
a
solution of
[NBu4]2[1-(MeS)B12H11] (1.31 g,1.95 mmol) in acetonitrile (35 mL). It was
AHCTUNGTRENNUNG
further stirred for 20 h and the acetonitrile was evaporated. The residue
was extracted from dichloromethane/water (1:1). The dichloromethane
layer was separated and dried over anhydrous sodium sulfate. The sol-
vent (CH2Cl2) was filtered and evaporated to give a light yellow semi-
solid (yield, 0.94 g, 88%). It was purified by column chromatography on
a silica gel column. M.p. 157–1588C; 1H NMR (250 MHz, CDCl3, 258C):
d=7.39 (d, 2H, J=8.22 Hz, CHAr), 7.24 (d, 2H, J=8.21 Hz , CHAr), 6.6
(dd, 1H, J=17.7, 10.55 Hz, CH), 5.66 (d, J=17.7 Hz, 1H, CH2), 5.27 (d,
J=10.9 Hz, 1H, CH2), 4.29 (d, J=13.59 Hz, 1H, CH2S), 3.76 (d, J=
13.58 Hz, 1H, CH2S), 3.12 (m, 8H, CH2N), 2.29 (s, 3H, MeS), 1.6 (m,
8H, CH2), 1.5 (m, 8H, CH2), 1.01 ppm (t, J=7.27 Hz, 12H, CH3);
11B NMR (80 MHz, CDCl3, 258C): d=À14.2 (d), À15.9 ppm (d); MS
(ESI): m/z calcd (C10H23SB12) 305.2733, found 305.2717.
Monomer synthesis
Synthesis of [1-MeSCH2CH2OC(O)C(Me)=CH2)-7-(Me2S)B12H10] (1)
Synthesis of monomer precursor [1-MeSCH2CH2OH)-7-(Me2S)B12H10]:
2-Chloroethanol (0.54 g, 6.7 mmol) was added to a solution of [NMe4][1-ACHTUNG-
TRENNUNG(MeS)-7-(Me2S)B12H10] (0.95 g, 2.94 mmol) in acetonitrile (30 mL). The
reaction mixture was stirred at 608C for five days, and the acetonitrile
was evaporated to give a yellow residue. The yellow residue was parti-
tioned between dichloromethane and water (30 mL, 1:1) and the di-
chloromethane layer was separated. The remaining aqueous layer was ex-
tracted once more with dichloromethane (30 mL). The dichloromethane
layers were combined and dried over anhydrous Na2SO4, filtered, and di-
chloromethane evaporated to give a yellow oil. The pure product was iso-
lated as a white solid by column chromatography on a silica gel column.
The pure product was a white solid (yield, 0.56 g, 65%). M.p. 104–1058C;
1H NMR (250 MHz, CDCl3, 258C): d=4.11 (m, 2H, CH2O), 3.37 (dt,
1H, J=13.9, 4.58 Hz, CH2S), 3.04 (m, 1H, CH2S), 2.67 (s, 3H, MeS), 2.57
(s, 6H, Me2S), 2.24 ppm (t, J=4.7 Hz, 1H, OH); 13C NMR (63 MHz,
CDCl3, 258C): d=59.04 (CH2OH), 45.49 (CH2S), 25.69 (Me2S),
24.76 ppm (MeS); MS (ESI): m/z calcd (C5H24S2O1B12Na1) 317.2361
[M+Na]+, found (317.2364).
Synthesis of [PPh3Me][1-(MeS-CH2-Ph-CH=CH2)B12H11] (3b): 4-Vinyl-
benzyl chloride (0.42 g, 2.75 mmol) was added to
a solution of
[PPh3Me]2[1-(MeS)B12H11] (1.94 g, 2.62 mmol) in acetonitrile (35 mL). It
AHCTUNGTRENNUNG
was further stirred overnight and the acetonitrile was evaporated. The
residue was extracted from dichloromethane/water (1:1). The dichloro-
methane layer was separated and dried over anhydrous sodium sulfate.
The solvent (CH2Cl2) was filtered and evaporated to give a light yellow
semi-solid (yield, 1.4 g, 93%). It was purified by column chromatography
on silica gel column. 1H NMR (250 MHz, CDCl3, 258C): d=7.66–7.91
AHCTUNGTRENNUNG
(m, 15H, CHAr(PPh Me)), 7.39 (d, 2H, J=8.22 Hz, CHAr), 7.24 (d, 2H, J=
8.21 Hz, CHAr), 6.6 (dd, 1H, J=17.7, 10.55 Hz, CH), 5.66 (d, J=17.7 Hz,
1H, CH2), 5.27 (d, J=10.9 Hz, 1H, CH2), 4.29 (d, J=13.59 Hz, 1H,
CH2S), 3.76 (d, J=13.58 Hz, 1H, CH2S), 2.87 (d, 3H, JHÀP 14 Hz, Me-P),
2.18 ppm (s, 3H, MeS); 11B NMR (80 MHz, CDCl3, 258C): d=À14.2 (d),
À15.9 ppm (d).
3
[(1-MeSCH2CH2OC(O)C(Me)=CH2)-7-(Me2S)B12H10] (1): Triethylamine
(0.35 g, 3.46 mmol) was added to a solution of [(1-MeSCH2CH2-OH)-7-
(Me2S)B12H10] (0.62 g, 2.11 mmol) in dichloromethane (30 mL). To the
mixture was added methacryolylchloride (0.26 g, 2.49 mmol) in dichloro-
methane (5 mL). The reaction mixture was stirred for 5 h in the dark.
After 5 h, the reaction mixture was extracted with water (25 mL), HCl
(0.048m), water (20 mL), saturated NaHCO3 (20 mL), and brine (20 mL).
The dichloromethane layer was separated, and the aqueous layer extract-
ed once more with dichloromethane. The dichloromethane layer was
dried over anhydrous Na2SO4, filtered, and then the dichloromethane
evaporated to give a thick oil (yield, 0.76 g, 82%). It was purified by
Polymer synthesis
Poly(7-(dimethylsulfido)decahydrododecaborane-1-methylsulfidoethyl-
methacrylate) (4a): AIBN (0.000251 g) was added to a solution of 1
(0.025 g, (0.069 mmol) in toluene (1 mL). The solution was heated at
1008C for 16 h. The white solid formed was isolated by vacuum filtration
and was washed with toluene and dichloromethane to give 4a. 1H-
AHCTUNGTRENNUNG
{11B} NMR (250 MHz, [D7]DMF, 258C): d=4.55 (brs, 2H, CH2O), 3.43
(brs, 2H, CH2S), 2 (v br) (brs, CH2), 2.72 (brs, 6H, Me2S), 2.63 (brs, 3H,
MeS), 1.45 (brs, 10H, BH), 1.05, 1.21 ppm (brs, CH3); 11B NMR
(80 MHz, [D7]DMF, 258C): d=À10.5 (sh), À15.2 (brs), À16.8 (d),
À17.9 ppm (d); GPC (DMF, 408C): MN =97010 gmolÀ1, polydispersity
index (PDI) 3.55.
chromatography on
a
silica gel column. M.p. 115–1168C; 1H NMR
(250 MHz, CDCl3, 258C): d=6.12 (q, J=1.27 Hz, 1H, C=CH2), 5.66
(quintet, J=1.58 Hz, 1H, C=CH2), 4.50 (m, 2H, CH2O), 3.43 (m, 1H,
CH2S), 3.10 (m, 1H, CH2S), 2.61 (s, 3H, MeS), 2.52 ppm (s, 6H, Me2S),
1.94 dd, J=1.58, 1.1 Hz, 3H, MeC=); 13C NMR (63 MHz, CDCl3, 258C):
d=166.84 (C=O), 135.89 (C=), 126.06 (CH2=), 59.92 (CH2O), 42.54
(CH2S), 25.96 (MeS), 24.45 (Me2S), 18.33 ppm (CH3); 11B NMR
(80 MHz, CDCl3, 258C) d=À8.2 (s), À12.8 (s), À15.3 (d), À16.6 ppm
(d); MS (EI): m/z calcd (C9H28S2O2B12) 362.2714, found 362.2717.
Poly(7-(dimethylsulfido)decahydrododecaborane-1-methylsulfidoethyl-
methacrylate) (4b): THF (2 mL) was added to a mixture of (0.1 g,
0.276 mmol) of 1 and AIBN (0.0028 g). The reaction mixture was stirred
at 648C. An oily substance separated after 1 h. The solution was stirred
for 20 h at 648C, cooled, and the THF was decanted. The oily residue
was washed with THF (2ꢂ5 mL) and the THF evaporated under vacuum
[(1-(MeS-CH2-Ph-CH=CH2))-7-(Me2S)B12H10] (2): 4-Vinylbenzylchloride
ACTHNUTRGNEUNG
to give 4b as a white solid. 1H{11B} NMR (250 MHz, [D6]DMSO, 258C):
d=4.33 (brs, 2H, CH2O), 3.31 (brs, 2H, CH2S), 2.65 (brs, 6H, Me2S),
2.54 (brs, 3H, Me2S), 1.47 (brs, 10H, BH), 1.03, 0.85 ppm (brs, CH3);
GPC (DMF, 10 mm LiCl, 708C): MN =90750 gmolÀ1, PDI=1.23.
(0.16 g, 1.05 mmol) was added to
a solution of [NMe4][1-CAHTUNGTNRUEGN(MeS)-7-
(Me2S)B12H10] (0.3 g, 0.93 mmol) in acetonitrile (15 mL). A white solid
(NMe4Cl) precipitated after 30 min of stirring. It was further stirred for
16 h, the acetonitrile was evaporated under vacuum, and the residue was
extracted from dichloromethane/water (1:1). The dichloromethane layer
was dried over anhydrous Na2SO4, filtered, and the solvent evaporated to
give a light yellow oil (yield, 0.29 g, 86%). It was purified by column
Poly(7-(dimethylsulfido)decahydrododecaborane-1-methylsulfido-4’-
methylstyrene) (5a): The synthetic procedure for 4a was used for the
synthesis of 5a (see Supporting Information). 1H NMR (250 MHz,
[D7]DMF, 258C): d=7.1–7.5 (brs, 2H, CHAr), 6.5–6.9 (brs, 2H, CHAr),
4.25–4.5 (brs, 1H, CH2S), 3.85–4.2 (brs, 1H, CH2S), 2.71 (brs, 6H,
chromatography on
a
silica gel column. M.p. 104–1058C; 1H NMR
(250 MHz, CDCl3, 258C): d=7.42 (d, J=8.21 Hz, 2H, CHAr), 7.24 (d, J=
8.21 Hz, 2H, CHAr), 6.74 (dd, J=16.11, 10.51 Hz, 1H, CH), 5.77 (d, 1H,
J=17.22 Hz, CH2), 5.31 (d, 1H, J=10.91 Hz, CH2), 4.34 (d, J=13.58 Hz,
1H, CH2S), 3.82 (d, J=13.43 Hz, 1H, CH2S), 2.54 (s, 6H, Me2S),
2.30 ppm (s, 3H, MeS); 13C NMR (63 MHz, CDCl3, 258C): d=22.16
(MeS), 25.73 (Me2S), 47.46 (CH2S), 115.58 (CH2=), 127.18, 129.95
(CHAr), 129.73 (CAr), 135.71 (CH=), 138.75 ppm (CAr); 11B NMR
(80 MHz, CDCl3, 258C): d=À9.14 (s), À13.49 (s), À15.15 (d),
À16.36 ppm (d); MS (EI): m/z calcd (C12H28S2B12) 366.2816, found
366.2744.
Me2S), 2.25–2.5 ppm (br, CH2
+ ACHTUNTGNRUEGN
MeS); 1H{11B} NMR (250 MHz,
[D7]DMF, 258C, TMS): d=1.6 ppm (brs, 10H, BH); 11B NMR (80 MHz,
[D7]DMF, 258C): d=À9.2 (brs), À15.8 ppm (brs); GPC (DMF, 10 mm
LiCl, 408C): MN =1.98 x103 gmolÀ1, PDI=11.4.
Poly(7-(dimethylsulfido)decahydrododecaborane-1-methylsulfido-4’-
methylstyrene) (5b): The synthetic procedure for 4b was used for the
synthesis of 5b (see Supporting Information). 1H {11B} NMR (250 MHz,
[D6]DMSO, 258C): d=7.5 (brs, 2H, CHAr), 6.6 (brs, 2H, CHAr), 4.27
(brs, 1H, CH2S), 4.01 (brs, 1H, CH2S), 2.54 (brs, 6H, Me2S), 2.32 (brs,
2196
www.chemeurj.org
ꢀ 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Chem. Eur. J. 2009, 15, 2190 – 2199

Homopolymers and Copolymers Containing closo-[B12H12]2À Boron Cages
FULL PAPER
MeS), 1.53 ppm (brs, 10H, BH); GPC (DMF, 10 mm LiCl, 708C): MN =
4260 gmolÀ1, PDI=2.69.
the formation of a white solid. The white solid was filtered and washed
with toluene (11). 1H NMR (250 MHz, [D6]DMSO, 258C, TMS): d=4.71
(brs, 1H, OH), 1.78 (brs, 2H, CH2O), 3.47 (brs, 2H, CH2C=O), 2.58
(brs, MeS +Me2S), 1.6–2.1 (brs, 2H, CH2), 0.66, 0.83 ppm (brs, 3H,
CH3).
Poly(tetrabutylammonium)(undecahydrododecaborane-1-methylsulfido-
4’-methylstyrene (6a): AIBN (0.0002 g) was added to a solution of 3
(0.018 g, 0.033 mmol) in 2-methyl-THF (1 mL), and the solution was
heated slowly to 758C. It was heated for 6 h at 758C. An oily substance
stuck to the wall of the glassware. The 2-methyl-THF was decanted and
the oily substance was washed with more 2-methylTHF. The oily sub-
stance was dried at 808C and a white solid was isolated (6a). 1H NMR
(250 MHz, CD3CN, 258C): d=6.7–7.2 (brs, 2H, CHAr), 6.15–6.7 (brs, 2H,
CHAr), 3.95–4.4.45 (brs, 1H, CH2S), 3.5–3.9 (brs, 1H, CH2S), 3.03 (m,
8H, CH2N), 2–2.25 (br m, 3H, MeS), 1.51 (m, 8H, CH2), 1.25 (q, 8H,
CH2), 0.96 ppm (t, 12H, CH3); 11B NMR (80 MHz, CDCl3, 258C): d=
À14.2 (d), À15.9 ppm (d); GPC (DMF, 10 mm LiCl, 708C): MN =3.98
x104 gmolÀ1, PDI=15.54.
Poly(7-(dimethylsulfido)decahydrododecaborane-1-methylsulfidoethyl-
methacrylate-co-hydroxyethylmethylmethacrylate) (12): Monomer
1
(0.05 g, 0.134 mmol) and AIBN (0.003 g) were added to HEMA (0.25 g,
1.92 mmol). The solution was heated at 808C for 18 h to give a white
polyACTHNUTRGNEmNUG er (insoluble polymer) (12). IR (KBr): n˜ =3448.6 (br, OH), 2950.6
(C–H), 2524.4 (B–H), 1719.1 cmÀ1 (C=O).
Poly(7-(dimethylsulfido)decahydrododecaborane-1-methylsulfidoethyl-
methacrylate-co-hydroxyethylmethylmethacrylate) (13): The synthetic
procedure for 12 was used for the synthesis of 13 (see Supporting Infor-
mation). 1H NMR (250 MHz, [D7]DMF, 258C, TMS): d=4.96 (brs, 1H,
OH), 4.45 (brs, 2/15H, CH2O), 4.07 (brs, 2H, CH2O), 3.77 (brs, 2H,
CH2C=O), 2.77 (brs, 3H/15, MeS), 2.68 (brs, 6H/15, Me2S), 2.95–2.2,
1.55–1.7, 1.2–1.35 (br m, CH2), 0.95, 1.06 ppm (brs, 3H, CH3); 11B NMR
(80 MHz, [D7]DMF, 258C, BF3·OEt2): d=À16 ppm (brs); IR (KBr): n˜ =
3437 (OH), 2950 (C–H, aliphatic), 2526 (B–H), 1725.8 cmÀ1 (C=O).
Poly(tetrabutylammonium)(undecahydrododecaborane-1-methylsulfido-
4’-methylstyrene (6b): The synthetic procedure of 4b was used for the
ACTHNUTRGNEUNG
synthesis of 6b (see Supporting Information). 1H{11B} NMR (250 MHz,
[D6]DMSO, 258C): d=7.48 (brs, 2H, CHAr), 6.46 (brs, 2H, CHAr), 4.21
(brs, 1H, CH2S), 3.82 (brs, 1H, CH2S), 3.17 (brs, 8H, CH2N), 2.22 (br m,
3H, MeS), 1.58 (brs, 8H, CH2), 1.32 (brs, 8H, CH2), 1.16 (s, 11H, BH),
0.95 ppm (brs, 12H, CH3); GPC (10 mm LiCl in DMF, 708C) MN =
9600 gmolÀ1, PDI=2.45.
Poly(7-(dimethylsulfido)decahydrododecaborane-methylsulfidoethylme-
thacrylate-co-hydroxyethylmethacrylate) (14): The synthetic procedure
for 12 was used for the synthesis of 14 (see Supporting Information).
1H NMR (250 MHz, [D7]DMF, 258C, TMS): d=4.86 (brs, 1H, OH, 4.46
(brs, 2H/15, CH2O), 4.18 (brs, 2H, CH2O), 3.74 (brs, 2H, CH2C=O),
2.785 (brs, 3H/15, MeS), 2.67 (brs, 6H/15, Me2S), 2.456, 1.959, 1.752 ppm
(brs, 2H, CH2); 11B NMR (80 MHz, [D7]DMF, 258C): d=À15.6 ppm
(br); IR (KBr): n˜ =3435 (OH), 2954 (C–H) aliphatic), 2523 (B–H)),
1735 cmÀ1 (C=O).
Poly(7-dimethylsulfido)decahydrodecaborane-1-methylsulfidoethylmetha-
crylate-co-methylmethaylacrylate) (7): Monomer 1 (0.0762 g, 0.21 m mol)
was dissolved in MMA (0.38 g, 3.8 mmol) and AIBN (0.005 g) was
added. The solution was heated at 1008C for 17 h to form a transparent
solid (7). 1H NMR (250 MHz, CDCl3, 258C): d=4.34 (brs, 2H/18,
CH2O), 3.62 (brs, 3H, CH3O), 3.15 (brs, 1H/18, CH2S), 3.4 (brs„ 1H/18,
CH2S), 2.65 (brs, 3H/18, MeS), 2.57 (brs, 6H/17.5, Me2S), 1.6–2.1 (br,
2H, CH2), 0.87, 1.043 ppm (brs, 3H, CH3); 11B NMR (80 MHz, CDCl3,
258C): d=À9.8 (br), À16 ppm (br); IR (KBr): n˜ =2997.9, 2952.16 ((C–
H)aliphatic), 2523.2 (B–H), 1734.30 cmÀ1 (C=O); GPC (THF, 408C):
MN =45000 gmolÀ1, PDI=1.98.
Poly(7-(dimethylsulfido)decahydrododecaborane-1-methylsulfidoethyl-
methacrylate-co-hydroxyethylmethacrylate) (15): The synthetic proce-
dure for 11 was used for the synthesis of 15 (see Supporting Informa-
tion). 1H NMR (250 MHz, [D6]DMSO, 258C, TMS): d=4.75 (brs, 1H,
OH), 4.15–4.55 (brs, 2H/15, CH2O), 3.99 (brs, 2H, CH2O), 2.66 (brs,
MeS + Me2S), 1.78, 1.57 ppm (brs, 2H, CH2).
Poly(7-(dimethylsulfido)decahydrododecaborane-1-methylsulfidoethyl-
methacrylate-co-methylmethacrylate) (8): Monomer
1
(0.042 g,
Poly(7-(dimethylsulfido)decahydrododecaborane-1-methylsulfidoethyl-
methacrylate-co-acrylamide) (16): Monomer 1 (0.035 g, 0.096 mmol), ac-
rylamide (0.175 g, 2.46 mmol), and AIBN (0.002 g) were added to aceto-
nitrile (1 mL). The solution was heated at 708C for 4 h. The white solid
formed was filtered and washed with acetonitrile (16). 1H NMR
(250 MHz, [D6]DMSO, 258C, TMS): d=7.07, 6.69 (brs, 2H, NH2), 4.15
(brs, 2H/15, CH2O), 2.51 (brs, 6H/15, Me2S), 1.97, 1.36 ppm (brs, 2H,
CH2); 11B NMR (80 MHz, [D6]DMSO, 258C): d=À16.9 ppm (br); IR
(KBr): n˜ =3342, 3196 (N–H), 2934 (C–H, aliphatic), 2523 (B–H),
1663 cmÀ1 (br, C=O).
0.112 mmol) and MMA (0.025 g, 0.25 mmol) were dissolved in toluene
(1 mL) and the solution was heated at 808C in the presence of AIBN
(0.0008 g) for 16 h. The white solid that precipitated was washed with tol-
1
uene and dried under vacuum (8). H NMR (250 MHz, [D7]DMF, 258C):
d=4.39 (brs, 2H, CH2O, 3.55 (brs, 3H, CH3O), 3.35 (brs, 2H, CH2S),
2.70 (brs, 3H, MeS), 2.65 (brs, 6H, Me2S), 1.7–2.2 (br, 4H, CH2), 0.78,
0.94 ppm (brs, 6H, CH3); 11B NMR (80 MHz, [D7]DMF, 258C): d=À9.3
(sh), À14.9 ppm (brs); IR (KBr): n˜ =2994, 2949 (CH2, CH3), 2519.8 (s,
B–H), 1731 cmÀ1 (s, C=O); GPC (DMF, 10 mm LiCl, 708C): MN =8.53ꢂ
104 gmolÀ1, PDI=4.06.
Poly(7-(dimethylsulfido)decahydrododecaborane-1-methylsulfidoethyl-
Poly(7-(dimethylsulfido)decahydrododecaborane-1-methylsulfidoethyl-
methacrylate-co-styrene) (9): Monomer 1 (0.05 g, 0.14 mmol) was added
to styrene (0.25 g, 2.4 mmol) followed by AIBN (0.003 g). The solution
was heated at 1008C for 16 h to give a transparent solid (9). 1H NMR
(250 MHz, CDCl3, 258C): d=6.6–7.1 (brs, CHAr), 6.15–6.6 (br, CHAr),
2.40 (brs, Me2S +MeS), 1.5–1.9 (brs, CH), 1.1–1.5 ppm (brs, CH2);
11B NMR (80 MHz, CDCl3, 258C): d=À9.8 (sh), À15.3 ppm (brs); IR
(KBr): n˜ =3082, 3059, 3025 cmÀ1 (C–H, aromatic), 2921, 2849 (CH2, CH,
aliphatic), 2517.3 (B–H), 1734.1 cmÀ1 (C=O), 1600.77 cmÀ1 (C=C, aromat-
ic); GPC (THF, DMF, 408C): MN =12000 gmolÀ1, PDI=2.72.
methacrylate-co-hydroxyethylmethylmethacrylate)
(17):
HEMA
(0.0306 g, 0.24 mmol) and 1 (0.0305 g, 0.084 mmol) were dissolved in tolu-
ene (0.5 mL) to form a clear solution. AIBN (0.0007 g) was added and
the reaction mixture was heated at 1008C for 2 h. A white solid stuck to
the surface of the reaction glass. The toluene was decanted, and the
white solid was washed with more toluene and dichloromethane and then
dried. The white solid was isolated by scraping it from the glass (17).
1H NMR (250 MHz, [D6]DMSO, 258C, TMS): d=4.83 (brs, 1H, OH),
4.15–4.5 (brs, 2H/2, CH2O), 3.91 (brs, 2H, CH2O), 3.59 (brs, 2H, CH2O),
3.27 (brs, 2H/2, CH2S), 2.62 (brs, 3H/2, MeS), 2.52 (brs, 6H/2, Me2S),
1.65–2.1 (brs, 3H, CH2a), 0.78, 0.955 ppm (brs, 4.5H, CH3); 11B NMR
(80 MHz, [D6]DMSO, 258C): d=À15.2 ppm (brs); IR (KBr): n˜ =3429
(brs, OH), 2938 (CH2, CH3), 2520 (B–H), 1726 cmÀ1 (C=O); GPC (DMF,
10 mm LiCl, 708C): MN =19050 gmolÀ1, PDI=2.52.
Poly(7-(dimethylsulfido)decahydrododecaborane-1-methylsulfidoethyl-
methacrylate-co-styrene) (10): The synthetic procedure for 9 was used
1
for the synthesis of 10 (see Supporting Information). H NMR (250 MHz,
[D6]DMSO, 258C, TMS): d=6.8–7.2 (brs, CHAr), 6.3–6.7 (br, CHAr), 2.55
(brs, Me2S
+ MeS), 1.7–1.2 (brs, CH), 1.1–1.65 ppm (brs, CH2); IR
Poly(7-(dimethylsulfido)decahydrododecaborane-1-methylsulfidoethyl-
methacrylate-co-hydroxyethylmethacrylate) (18): The synthetic proce-
dure for 17 was used for the synthesis of 18 (see Supporting Informa-
(KBr): n˜ =3082, 3059, 3025 (C–H, aromatic), 2925, 2849 (CH2, CH)),
2517.7 (B–H), 1729 (C=O), 1600 cmÀ1 (C=C, aromatic); GPC (DMF,
10 mm LiCl, 708C): MN =1.65ꢂ105 gmolÀ1, PDI=4.38.
1
tion). H NMR (250 MHz, [D6]DMSO, 258C, TMS): d=4.82 (brs, 0.18H,
Poly(7-(dimethylsulfido)decahydrododecaborane-1-methylsulfidoethyl-
methacrylate-co-hydroxyethylmethylmethacrylate) (11): HEMA (0.125 g,
0.96 mmol), 1 (0.025 g, 0.069 mmol), and AIBN (0.002 g) were added to
toluene (0.5 mL) and the solution was heated at 808C for 6 h resulting in
OH), 4.1–4.5 (brs, 2H/3, CH2O), 4.00 (brs, 2H, CH2O), 3.59 (brs, 2H,
CH2O), 3.25 (brs, 2H/3, CH2S), 2.59 (brs, 3H/3, MeS), 2.52 (brs, 6H/3,
Me2S), 1.65–2.1 (brs, 2.67H, CH2 aliphatic), 0.78, 0.955 ppm (brs, 1H,
CH3); IR (KBr): n˜ =3448 (brs, OH), 2952 (CH2, CH3), 2520 (B–H),
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S. Stricker, J. Parquette, S. G. Shore et al.
1734 cmÀ1 (C=O); 11B NMR (80 MHz, [D6]DMSO, 258C): d=À15.6 ppm;
GPC (DMF, 10 mm LiCl, 708C): MN =67720 gmolÀ1, PDI=8.3.
Vysokomol. Soedin. Ser. A 1974, 16, 987; V. P. Lebedev, T. M. Bab-
chinitser, N. I. Bekasova, L. G. Komarova, D. Ya. Tsvankin, V. V.
Korshak, Chem. Abstr. 1974, 81, 106143; n) S. R. Rafikov, S. A. Pav-
lova, I. V. Zhuravleva, R. S. Aupova, P. M. Valetskii, A. I. Kalachev,
S. V. Vinogradova, V. V. Korshak, Dokl. Akad. Nauk SSSR 1973,
213, 603; S. R. Rafikov, S. A. Pavlova, I. V. Zhuravleva, R. S.
Aupova, P. M. Valetskii, A. I. Kalachev, S. V. Vinogradova, V. V.
Korshak, Chem. Abstr. 1974, 80, 134162; o) R. S. Ayupova, I. V.
Zhuravleva, Izv. Akad. Nauk Kaz. SSR Ser. Khim. 1973, 23, 78;
R. S. Ayupova, I. V. Zhuravleva, Chem. Abstr. 1973, 79, 19329;
p) A. F. Zhigach, N. S. Fedotov, I. G. Sarishvili, B. A. Akimov, F. N.
Vishnevskii, L. A. Efremova, V. F. Mironov, U.S.S.R. 1967 204594;
A. F. Zhigach, N. S. Fedotov, I. G. Sarishvili, B. A. Akimov, F. N.
Vishnevskii, L. A. Efremova, V. F. Mironov, Chem. Abstr. 1968, 69,
3463; q) A. F. Zhigach, M. V. Sobolevskii, I. G. Sarishvili, V. A. Za-
myatina, Z. M. Frolova, G. S. Shostenko, P. Z. Sorokin, B. A.
Akimov, U.S.S.R. 1967, 203905.
Poly(7-(dimethylsulfido)decahydrododecaborane-1-methylsulfido-4’-
methylstyrene-co-styrene (19): The synthetic procedure for 9 was used
1
for the synthesis of 19 (see Supporting Information). H NMR (250 MHz,
CD2Cl2, 258C, TMS): d=6.2–6.7, 6.8–7.2 (br, 5.3H, CHAr), 4.19 (brs, 1/
18, CH2S), 3.68 (brs, 1/18, CH2S), 2.46 (brs, 9/18, Me2S + MeS), 1.9–2.2,
1.6–1.9, 1.1–1.6 ppm 3H, CH aliphatic); 11B NMR (80 MHz, CD2Cl2,
258C): d=À9.2 (sh), À15.2 ppm (t); IR (KBr): n˜ =3082, 3058, 3024 (C-
H-Ar), 2921, 2848 (C–H, aliphatic), 2517 (B–H), 1601 cmÀ1 (C–CAr);
GPC (THF, 408C): MN =9342 gmolÀ1, PDI=3.69.
Acknowledgements
[10] a) V. I. Sergina, L. G. Klimanova, Komarova, N. I. Bekasova, V. V.
Korshak, Plast. Massy 1972, 11, 27; b) P. M. Valetskii, L. A. Glivka,
L. V. Dubrovina, S. V. Vinogradova, V. G. Danolov, V. I. Stanko,
V. V. Korshak, Vysokomol. Soedin. Ser. A 1973, 15, 1227; P. M. Val-
etskii, L. A. Glivka, L. V. Dubrovina, S. V. Vinogradova, V. G. Da-
nolov, V. I. Stanko, V. V. Korshak, Chem. Abstr. 1973, 79, 115910;
c) V. V. Korshak, N. I. Bekasova, M. P. Prigozhina, Vysokomol.
Soedin. Ser. B 1973, 15, 422; V. V. Korshak, N. I. Bekasova, M. P. Pri-
gozhina, Chem. Abstr. 1973, 79, 115911; d) V. V. Korshak, P. M. Val-
etskii, L. A. Glivka, S. V. Vinogradova, N. S. Titova, V. I. Stanko, Vy-
sokomol. Soedin. A 1972, 14, 1043; Chem. Abstr. 1972, 77, 88880;
e) T. N. Balikova, P. N. Gribkova, L. A. Glivka, P. M. Valetskii, S. V.
Vinogradova, V. V. Korshak, Vysokomol. Soedin. Ser. A 1973, 15,
2441; T. N. Balikova, P. N. Gribkova, L. A. Glivka, P. M. Valetskii,
S. V. Vinogradova, V. V. Korshak, Chem. Abstr. 1974, 80, 60379;
f) V. V. Korshak, P. N. Gribkova, T. N. Balykova, L. G. Komarova,
N. I. Bekasova, Vysokomol. Soedin. Ser. A 1972, 14, 1557; V. V. Kor-
shak, P. N. Gribkova, T. N. Balykova, L. G. Komarova, N. I. Bekaso-
va, Chem. Abstr. 1972, 77, 1104703; g) V. V. Korshak, N. I. Bekaso-
va, V. V. Vagin, A. A. Izyneev, Vysokomol. Soedin. Ser. A 1974, 16,
718; V. V. Korshak, N. I. Bekasova, V. V. Vagin, A. A. Izyneev,
Chem. Abstr. 1974, 81, 136566; h) V. V. Korshak, V. V. Vagin, N. I.
Bekasova, A. A. Izyneev, Dokl. Akad. Nauk SSSR 1973, 212, 638;
V. V. Korshak, V. V. Vagin, N. I. Bekasova, A. A. Izyneev, Chem.
Abstr. 1974, 80, 83948.
[11] a) Y. Qin, E. Bakker, Anal. Chem. 2003, 75, 6002; b) A. F. Zhigach,
Yu. G. Chikishev, V. N. Siryatskaya, S. L. Sosin, V. V. Korshak, Vyso-
komol. Soedin. Ser. B 1970, 12, 771; A. F. Zhigach, Yu. G. Chikishev,
V. N. Siryatskaya, S. L. Sosin, V. V. Korshak, Chem. Abstr. 1971, 74,
32126; see also ref. [9k].
[12] a) R. L. Barnes, D. Grafstein, Ger. Offen., 1970, 1948598; R. L.
Barnes, D. Grafstein, Chem. Abstr. 1971, 74, 65112; b) I. K. Spiker,
R. Barnes, Soc. Aerosp. Mater. Process Eng., 2nd Tesh. Conf. Proc.,
1970, 23; I. K. Spiker, R. Barnes, Chem. Abstr. 1971, 4, 54214; c) R.
Barnes, E. Hughes, Sci. Tech. Aerosp. Rep. 1968, 6, 4084; R. Barnes,
E. Hughes, Chem. Abstr. 1969, 71, 71544.
This work was supported in part by the Army Research Office.
[1] E. L. Muetterties, J. H. Balthis, Y. T. Chia, W. H. Knoth, H. C.
Miller, Inorg. Chem. 1964, 3, 444.
[2] a) N. Kiyoshi, J. P. Hyogo, K. Najma, US patent 6605817, 2003;
b) D. G. Penn, O. H. Woodmere, US patent 6373066, 2002.
[3] a) R. E. Johnson, N. J. Hobken, US patent 4946919, 1990; b) T. M.
Keller, L. J. Henderson, US patent 5292779, 1994; c) T. M. Keller,
E. J. Houser, US patent 6495483, 2002.
[4] a) T. K. Dougherty, N. H. Harris, J. R. Chow, B. M. Pierce, D. A.
Whelan, US patent 5317058, 1994; b) T. K. Dougherty, N. H. Harris,
J. R. Chow, B. M. Pierce, D. A. Whelan, US patent 5574077, 1996.
[5] Y. Quin, E. Bakker, Anal. Chem. 2003, 75, 6002.
[6] A. H. Soloway, W. Tjarks, B. A. Barnum, F. Rong, R. F. Barth, I. M.
Codogni, J. G. Wilson, Chem. Rev. 1998, 98, 1515.
[7] a) J. Dai, C. K. Ober, L. Wang, F. Cerrina, P. F. Nealey, Proc. SPIE-
Int. Soc. Opt. Eng. 2002, 4690, 1193; b) J. Dai, C. K. Ober, L. Wang,
F. Cerrins, P. Nealey, US patent 20040241574 (published applica-
tion), 2004.
[8] Y. Osada, A. T. Bell, M. M. Shen, US patent 4320219, 1982.
[9] a) J. Green, N. Mayes, M. S. Cohen, J. Polym. Sci. 1964, 2, 3113;
b) V. V. Korshack, A. F. Zhigach, M. V. Sobolevskii, I. G. Sarishvvili,
I. M. Leonova, Vysokomol. Soedin. Ser. A 1970, 13, 2737; V. V. Kor-
shack, A. F. Zhigach, M. V. Sobolevskii, I. G. Sarishvvili, I. M. Leo-
nova, Chem. Abstr. 1971, 4, 54214; c) T. L. Heying, US patent
3121118, 1961; d) T. L. Heying, R. P. Alexander, US patent 3117164,
1961; e) J. W. Ager, R. P. Alexander, T. L. Heying, US patent
310858, 1965; f) J. W. Ager, J. A. Reid, US patent 3109026, 1963;
g) V. V. Korshak, S. V. Vinogradova, P. M. Valetski, V. I. Stanko,
T. N. Vostrikova, A. I. Kalachev, U.S.S.R. 1967, 235300; V. V. Kor-
shak, S. V. Vinogradova, P. M. Valetski, V. I. Stanko, T. N. Vostriko-
va, A. I. Kalachev, Chem. Abstr. 1970, 73, 4580; h) P. I. Ivanov, V. S.
Matochꢃkin, A. I. Kalchev, Yu. V. Zelenev, P. M. Valetskii, S. V. Vi-
nogradove, V. V. Korshak, Dokl. Akad. Nauk SSSR 1973, 213, 338;
P. I. Ivanov, V. S. Matochꢃkin, A. I. Kalchev, Yu. V. Zelenev, P. M.
Valetskii, S. V. Vinogradove, V. V. Korshak, Chem. Abstr. 1974, 80,
71298; i) L. V. Dubrovina, N. F. Ivanova, A. I. Kalachev, P. M. Valet-
skii, S. V. Vinogradova, Vysokomol. Soedin. Ser. B 1973, 15, 835;
L. V. Dubrovina, N. F. Ivanova, A. I. Kalachev, P. M. Valetskii, S. V.
Vinogradova, Chem. Abstr. 1974, 804, 1290; j) E. K. Lyamenkova,
S. V. Vinogradova, V. I. Stanko, V. V. Korshak, Vysokomol. Soedin.
Ser. A 1974, 16, 305; E. K. Lyamenkova, S. V. Vinogradova, V. I.
Stanko, V. V. Korshak, Chem. Abstr. 1974, 81, 13917; k) J. Green, N.
Mayes, A. P. Kotloby, M. M. Fein, E. L. OꢃBrien, M. S. Cohen,
Polym. Lett. 2 1964, 109; l) P. M. Valetskii, E. K. Lyamenkova, T. M.
Babchinister, A. I. Kalachev, V. P. Lebedev, S. V. Vinogradova, V. I.
Stanko, V. V. Koshak, Vysokomol. Soedin. Ser. A 1973, 15, 2200;
P. M. Valetskii, E. K. Lyamenkova, T. M. Babchinister, A. I. Kala-
chev, V. P. Lebedev, S. V. Vinogradova, V. I. Stanko, V. V. Koshak,
Chem. Abstr. 1974, 80, 83687; m) V. P. Lebedev, T. M. Babchinitser,
N. I. Bekasova, L. G. Komarova, D. Ya. Tsvankin, V. V. Korshak,
[13] a) M. Colquhoun, D. F. Lewis, P. L. Herbertson, K. Wade, Polymer
1997, 17, 539; b) M. Colquhoun, D. F. Lewis, G. A. Daniels, P. L.
Herbertson, J. A. H. MacBride, I. R. Stephenson, K. Wade, Polymer
1997, 38, 2447.
[14] a) S. F. Reed, J. Polym. Sci. Polym. Chem. Ed. 1973, 11, 305; b) J. Y.
Dong, E. Manias, T. C. Chung, Macromolecules 2002, 35, 3439.
[15] a) J. L. Henderson, T. M. Keller, Macromolecules 1994, 27, 1660;
b) M. K. Kolel-veetil, H. W. Beckham, T. M. Keller, Chem. Mater.
2004, 16, 3162; c) D. Y. Son, T. M. Keller, J. Polym. Sci. Polym.
Chem. Ed. 1995, 33, 2969; d) M. M. Fein, J. Green, E. L. OꢃBrien,
US patent 3431234, 1969; e) N. Mayes, US patent 3440260, 1969;
f) J. Green, US Patent 3738878, 1973; g) A. F. Sobolevskii, K. P. Zhi-
gach, I. G. Grinevich, E. M. Sarishvili, E. M. Kozyreva, Plast. Massy
1966, 1, 21; h) A. D. Delman, J. J. Kelly, B. B. Simms, J. Polymer Sci.
A1 1970, 8, 111; i) R. L. Barnes, W. M. Block, D. Graftein, U. S.
2198
www.chemeurj.org
ꢀ 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Chem. Eur. J. 2009, 15, 2190 – 2199

Homopolymers and Copolymers Containing closo-[B12H12]2À Boron Cages
FULL PAPER
patent 3730950, 1973; j) T. M. Keller, E. J. Houser, US patent
598032, 1999; see also ref. [9k].
[16] a) P. Jaffe, U. S. Natl. tech. Inform. Serv. 1965, AD 625680, 95;
b) R. L. Barnes, W. M. Block, D. Grafstein, US patent 3730950,
1973; c) A. D. Delman, J. J. Kelly, B. B. J. Simms, Polym. Sci. A1
1970, 8, 111.
[17] a) B. A. Akimov, A. F. Zhigach, I. G. Sarishvili, M. V. Sobolevskii,
U.S.S.R. 1968, 231797; B. A. Akimov, A. F. Zhigach, I. G. Sarishvili,
M. V. Sobolevskii, Chem. Abstr. 1969, 70, 68916; b) N. I. Bekasova,
V. V. Korshak, M. P. Prigozhina, A. I. Solomatina, Vysokomol.
L. A. Efremova, Vysokomol. Soedin. Ser. B 1970, 12, 75; V. V. Kor-
shak, I. G. Sarishvili, A. F. Zhigach, B. A. Akimov, L. A. Efremova,
Chem. Abstr. 1971, 74, 32031; h) S. M. Samoillov, E. P. Samorokova,
V. B. Losev, V. N. Monastyrski, U.S.S.R. 1973, 328013; S. M. Samoil-
lov, E. P. Samorokova, V. B. Losev, V. N. Monastyrski, Chem. Abstr.
1974, 80, 37620; i) E. A. Zimakova, E. A. Chernyshev, V. N. Lizina,
N. G. Konyeva, A. F. Zhigach, V. N. Siryatskaya, U.S.S.R. 1973,
384837; E. A. Zimakova, E. A. Chernyshev, V. N. Lizina, N. G. Ko-
nyeva, A. F. Zhigach, V. N. Siryatskaya, Chem. Abstr. 1974, 80,
37624.
Soedin. Ser. B 1973, 629; N. I. Bekasova, V. V. Korshak, M. P. Prigoz-
hina, A. I. Solomatina, Chem. Abstr. 1974, 80, 48429.
[21] V. A. Sergeev, V. V. Korshak, L. I. Vdovina, L. I. Zakharkin, V. N.
Kalinin, V. G. Danilov, Dokl4th Vses. Konf. Khim. Atsetilena, 1972,
3, 130; V. A. Sergeev, V. V. cKorshak, L. I. Vdovina, L. I. Zakharkin,
V. N. Kalinin, V. G. Danilov, Chem. Abstr. 1974, 81, 26325.
[22] T. Kanayama, H. Hiura, US patent 6680411, 2004.
[23] E. J. M. Hamilton, G. T. Jordan, E. A. Meyers, S. G. Shore, Inorg.
Chem. 1996, 35, 5335.
[18] a) P. N. Gribkova, T. N. Balykova, L. A. Glivka, P. M. Vatelskii, S. V.
Vinogradova, V. V. Korshak, Vysokomol. Soedin. Ser. A 1973, 15,
1506; P. N. Gribkova, T. N. Balykova, L. A. Glivka, P. M. Vatelskii,
S. V. Vinogradova, V. V. Korshak, Chem. Abstr. 1974, 80, 4008.
[19] a) V. V. Korshak, D. P. Kunchuliya, N. I. Bekasova, Vysokomol.
Soedin. Ser. A 1973, 15, 2195; b) N. I. Bekasova, Nuova Chim. 1974,
50, 47; N. I. Bekasova, Chem. Abstr. 1974, 81, 37884.
[24] R. G. Kultyshev, J. Liu, E. A. Meyers, S. G. Shore, Inorg. Chem.
2000, 39, 3333.
[20] a) S. L. Clark, H. L. Goldstein, T. L. Heying, US patent 312117,
1964; b) P. Jaffe, U. S. Natl. tech. Inform. Serv. 1965, AD 625680, 95;
c) A. F. Zhigach, Yu. G. Chikishev, V. N. Siryatskaya, S. L. Sosin,
V. V. Korshak, Vysokomol. Soedin. Ser. B 1970, 12, 771; A. F. Zhi-
gach, Yu. G. Chikishev, V. N. Siryatskaya, S. L. Sosin, V. V. Korshak,
Chem. Abstr. 1971, 74, 32126; d) J. R. Wright, T. J. Klingen, J. Inorg.
Nucl. Chem. 1973, 35, 53; e) S. F. Reed, J. Polym. Sci. A-1 1971, 9,
825; f) T. J. Klingen, J. R. Wright, J. Inorg. Nucl. Chem. 1973, 35,
1451; g) V. V. Korshak, I. G. Sarishvili, A. F. Zhigach, B. A. Akimov,
[25] R. G. Kultyshev, J. Liu, S. Liu, W. Tjarks, A. H. Soloway, S. G.
Shore, J. Am. Chem. Soc. 2002, 124, 2614.
[26] Z. Otwinowsky, W. Minor, “Processing of X-ray Diffraction Data
Collected in Oscillation Mode, Macromolecular Crystallography,
Part A”, Methods in Enzymology (Eds.: C. W. Carter, Jr., R. M.
Sweet) Vol. 276, Academic Press, New York, 1997, pp. 307–326.
Received: July 15, 2008
Published online: January 14, 2009
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