Article
Macromolecules, Vol. 43, No. 22, 2010 9339
1,3,5,7,9,11,13,15-((octa(3-(5-(phenylethynyl)isoindolinyl-1,3-
dione)phenyl)pentacyclo[9.5.1.13,9.15,15.17,13] octasiloxane (Octa-
phenylPEPI-POSS), and tricyclo[7.3.3(3,7)]octasiloxane-
5,11,14,17-tetraol-1,3,5,7,9,11,14,17-octaphenyl (Ph8tetrasilanol-
POSS) were obtained from Hybrid Plastics. Solvents such
as toluene, tetrahydrofuran (THF), hexane, diethyl ether, and
dimethylacetimide (DMAc) were obtained from Aldrich and
purified prior to use. Magnesium turnings, (N-trimethyl-
silyl)2-4-bromoaniline, aniline, and triethylamine were obtained
from Aldrich and used as received. Phenylethynyl phthalic
anhydride (PEPA) and 2,20-bis(3,4-dicarboxyphenyl)hexafluoro-
propane dianhydride (HFDA) were obtained from Chriskev
Company. p-Phenylenediamine (p-PDA) was obtained from
Aldrich. Trichloromethylsilane, from Gelest, and tetrachloro-
silane, from United Chemical Technologies, were distilled prior
to use. The protected-aminochlorosilanes were synthesized
by the literature methods.34 For completeness, short synthesis
descriptions were provided in the Suppoorting Information.
Oligoimides of n moles of HFDA, n þ 1 mol of p-PDA, and
2 mol of PEPA as the end functionality, where n = 1 (HFPE-n-1) or
9 (HFPE-n-9), were synthesized using the PMR method.31
Synthetic Methods. Synthesis of Phenyl8bisaniline-POSS
(Ph8bisaniline-POSS). Under a nitrogen atmosphere in a dry-
combined organic layers were extracted with water, dilute HCl,
water, and saturated brine and then dried with magnesium
sulfate. After filtration, most of the solvent was removed under
vacuum, and the product (9.37 g, 90% yield) was precipitated
into methanol, filtered, and dried at 40 °C in a vacuum oven
overnight. NMR resonances (ppm) follow. 29Si NMR, δ: -77.9
(3 Si), -78.2 (3 Si), -78.3 (1 Si), -100.4 (1 Si). 13C NMR, δ:
134.45, 134.39, 131.11, 131.05, 130.22, 130.10, 128.11, 128.10.
1H NMR, δ: 7.87 (14 H’s, multiplet), 7.51 (7 H’s, multiplet), 7.45
(14 H’s, multiplet), 3.9 (1 H, broad singlet).
Synthesis of Ph- and Ibu-monosiloxymethyldianiline-POSS
(Ph7 or Ibu7-da-POSS). Under a nitrogen atmosphere, a diethyl
ether (5 mL) solution of triethylamine (0.314 g, 3.1 mmol) and
(di((N-trimethylsilyl)2-aniline)-4,40-(chloromethylsilane) (1.701 g,
3.08 mmol) was added, dropwise, to a POSS solution of either
Ibu7OH-POSS (2.50 g, 3.00 mmol) or Ph7OH-POSS (2.92 g,
3.00 mmol) dissolved in a mixture of diethyl ether (15 mL) and
THF (2 mL), and stirred overnight at room temperature. The
solution was filtered to remove HNEt3Cl, and most of the
solvent was removed under vacuum. Addition of acidified
methanol (50 mL) and stirring the suspension for an hour at
room temperature produced the free amine. The product
(∼60% yield) was isolated by filtration, and dried in a vacuum
oven overnight at 60 °C. NMR resonances (ppm) follow.
Ph7da-POSS. 29Si NMR, δ: -8.0 (1 Si), -78.1 (3 Si), -78.2
(4 Si), -109.4 (1 Si). 13C NMR, δ: 147.75, 135.63, 134.53, 134.41,
130.96, 130.88, 130.38, 130.32, 128.06, 127.99, 125.63, 114.57,
-0.38. 1H NMR, δ: 7.83 (14 H’s, multiplet), 7.80 (4 H’s, multi-
plet), 7.52 (7 H’s, multiplet), 7.44 (14 H’s, multiplet), 6.56 (4 H’s,
multiplet), 3.82 (4 H’s, broad singlet), 0.62 (3 H’s, singlet).
Ibu7da-POSS. 29Si NMR, δ: -9.4 (1 Si), -67.0 (3 Si), -67.9
(4 Si), -109.9 (1 Si). 13C NMR, δ: 147.54, 135.60, 126.39, 114.63,
25.91, 24.06, 23.97, 22.72, 22.67, 22.54, -0.32. 1H NMR, δ: 7.40
(4 H’s, multiplet), 6.67 (4 H’s, multiplet), 3.79 (4 H’s, broad
singlet), 1.88 (7 H’s, multiplet), 0.97 (42 H’s, multiplet), 0.60
(17 H’s, multiplet).
box,
a solution of ((N-trimethylsilyl)2-aniline4(dichloro-
methylsilane) (2.953 g, 8.42 mmol), triethylamine (1.857 g, 18.4
mmol) and THF (10 mL) was added dropwise via an addition
funnel into a well-stirred solution of Ph8tetraol-POSS (4.455 g,
4.17 mmol) and THF (40 mL) in a 100 mL round-bottom flask.
The POSS solution became cloudy after the addition of a few
drops of the dichloromethylsilane/triethylamine solution, indi-
cating formation of insoluble HNEt3Cl salt. After 30 min of
stirring, this salt was separated by filtration and the solvent was
removed under vacuum. Addition of diethyl ether (2 mL)
followed by a solution of acidified methanol (50 mL) gave a
white suspension of product that was stirred at room tempera-
ture for 1 h. The product (3.90 g, 70% yield) was isolated by
filtration and dried in a vacuum oven overnight at 60 °C. NMR
resonances (ppm) follow. 29Si NMR, δ: -29.7 (4 Si), -78.2
(8 Si), -79.1 (2 Si), -79.3 (4 Si), -79.4(2 Si). 13C NMR, δ:
148.27, 135.13, 134.39, 134.35, 134.30, 134.22, 132.29, 131.40,
131.19, 130.98, 130.52, 130.47, 130.38, 130.24, 127.93, 127.88,
127.69, 127.52, 124.64, 114.56, -0.10. 1H NMR, δ: 7.8-7.1
(44 H’s, overlapping multiplets), 6.6 (4 H’s, doublet), 3.6 (4 H’s,
NH2, broad singlet), 0.58 (6 H’s, CH3, singlet).
Synthesis of Ph- or Ibu-monosiloxymethyldi(phenylethynyl-
phthalimide)-POSS (Ph7 or Ibu7diPEPI-POSS). Under
a nitrogen atmosphere, a well-stirred solution of either
Ph7da-POSS (0.250 g, 2.06 mmol) or Ibu7da-POSS (0.249 g,
2.36 mmol) and PEPA (2.03 equiv) in anhydrous THF (2 mL)
and anhydrous toluene (2 mL) was heated to 60 °C for 2 h, and
then to 105 °C for 20 h. Most of the solvent was removed under
vacuum, and the product (∼90% yield) was precipitated into
methanol, filtered, and dried in a vacuum oven at 125 °C for
24 h. Both products show a small impurity by silicon NMR.
NMR resonances (ppm) follow. Ph7diPEPI-POSS. 29Si NMR, δ:
-8.7 (1 Si), -77.8 (3 Si), -78.2 (4 Si), -109.3 (1 Si). 13C NMR,
δ: 166.4, 166.3, 137.1, 136.3, 134.7, 134.2, 134.1, 133.0, 132.0,
131.8, 131.7, 130.8, 130.3, 130.1, 130.0, 129.8, 129.3, 128.5,
Synthesis of Phenyl8bis(phenylethynylphthalimide)-POSS
(Ph8bisPEPI-POSS). Under a nitrogen atmosphere, a well-
stirred solution of Ph8bisaniline-POSS (0.248 g, 0.186 mmol)
and PEPA (0.095 g, 0.38 mmol) in anhydrous THF (2 mL) and
anhydrous toluene (2 mL) was heated to 60 °C for 2 h and then to
105 °C for 20 h. Most of the solvent was removed under vacuum,
and the product (0.30 g, 90% yield) was precipitated into
methanol, filtered, and dried in a vacuum oven at 125 °C for
24 h. NMR resonances (ppm) follow. 29Si NMR, δ: -31.2,
-77.9, -78.9, -79.1, -79.3. 13C NMR, δ: 166.4, 166.3, 137.1,
136.1, 134.0, 133.9, 133.2, 132.0, 131.8, 131.6, 130.9, 130.5,
130.4, 130.3, 130.0, 129.2, 128.5, 127.8, 127.8, 127.7, 127.6,
126.5, 125.5, 123.7, 121.0, 94.2, 87.7, -0.4. 1H NMR, δ:
8.2-7.2 (64 H’s, overlapping multiplets), 0.71 (6 H’s).
1
127.9, 127.8, 126.5, 125.4, 123.7, 122.0, 94.3, 87.7, -0.9. H
NMR, δ: 8.1-7.2 (59 H’s), 0.61 (3 H’s). Ibu7diPEPI-POSS.
29Si NMR, δ: -10.2 (1 Si), -66.7 (3 Si), -67.8 (4 Si), -109.6
(1 Si). 13C NMR, δ: 166.5, 166.4, 137.1, 136.8, 134.7, 132.9,
132.0, 131.8, 131.5, 130.3, 130.0, 129.2, 129.1, 128.5, 128.1,
126.5, 126.4, 125.4, 123.7, 123.6, 122.0, 94.2, 87.7, 25.7, 25.6,
23.8, 23.7, 22.4, 22.3, -0.9. 1H NMR, δ: 8.1-7.2 (24 H’s), 1.9
(7 H’s), 1.0 (42 H’s), 0.67 (17 H’s).
Synthesis of Phenyl7monohydroxyl-POSS (Ph7OH-POSS).
Under a nitrogen atmosphere, a solution of silicon tetrachloride
(1.903 g, 11.2 mmol) and triethylamine (3.572 g, 35.3 mmol) in
THF (20 mL) was added dropwise to a well-stirred THF (70 mL)
solution of Ph7trisilanol-POSS (9.965 g, 10.7 mmol) in a
100 mL round-bottom flask. After being stirred overnight at
room temperature, the suspension was filtered, collecting both
Ph7Cl-POSS product and NEt3HCl salt byproduct. After these
solids were dissolved in THF (5 mL) and chloroform (15 mL),
the silicon-chlorine bond was hydrolyzed with water (15 mL)
and dilute HCl (2 mL) over a 90 min period. The aqueous
layer was removed and extracted twice with chloroform. The
Synthesis of Phenyl7aniline-POSS (Ph7aniline-POSS). In a
drybox, under a nitrogen atmosphere, a THF (5 mL) solution
of ((N-trimethlsilyl)2-aniline-4-(trichlorosilane) (0.871 g, 2.35
mmol) and triethylamine (0.680 g, 6.72 mmol) was slowly added
in a dropwise manner to a well-stirred THF (10 mL) solution of
Ph7trisilanol-POSS (2.015 g, 2.16 mmol) in a 100 mL round-
bottom flask. This solution became cloudy after the addition of
a few drops, indicating formation of HNEt3Cl salt. After stirring
at room-temperature overnight, filtration was used to separate
product from salt, and the solvent was removed under vacuum.
The free-amine was produced by addition of diethyl ether (2 mL)
followed by a solution of acidified methanol (20 mL) and