by column chromatography over silica gel eluting with
hexane–ether (10 : 1) to give the title compound (600 mg,
(–C(CH3)3), 136.0 (Si–CHLCH–C(O)–), 147.8 (Si–CHLCH–
C(O)–), 166.0 (–COO–); IR (neat) 2978, 2948, 2894, 1708,
1365, 1243, 1229, 1154, 836, 687, 620 cm21. MS (EI) m/z 374
(M+); exact mass M+ 374.1935 (calcd for C16H38O2Si4,
374.1949). Anal. Calcd for C16H38O2Si4: C, 51.27; H, 10.22.
Found: C, 51.20; H, 10.32%.
1
61%) (Rf 5 0.4). Colorless oil; H NMR (400 MHz, CDCl3) d
1.77 (m, 2H), 2.12 (m, 2H), 2.43 (t, J 5 7.4 Hz, 2H), 4.46 (q,
J 5 8.4 Hz, 2H), 4.99 y 5.06 (m, 2H), 5.77 (m, 1H); 13C
NMR (100.6 MHz, CDCl3) d 23.8 (–CH2CH2CH2–), 32.9
(–CH2CH2CH2–), 60.4 (q, –CH2–CF3, JC–F 5 36.6 Hz), 115.8
(CH2LCH–), 123.1 (q, –CH2–CF3, JC–F 5 277.0 Hz), 137.3
(CH2LCH–), 172.0 (–CO2–); IR (neat) 3082, 2979, 2941, 2872,
1761, 1643, 1415, 1282, 1169, 977, 917, 840 cm21. MS (EI) m/z
196 (M+), 97 (M+ 2 OCH2CF3), 83 (CH2CF3); exact mass M+
196.0711 (calcd for C8H11O2F3, 196.0711).
(Z)-2-Hydroxyethyl 3-[tris(trimethylsilyl)silyl]propenoate
(3g). (Yield 75%) (Rf 5 0.2, hexane–ether 5 2 : 1): Colorless
oil; 1H NMR (400 MHz, CDCl3) d 0.17 (s, 27H), 3.83 (m, 2H),
4.24 (m, 2H), 6.63 (d, 1H, J 5 13.7 Hz), 6.82 (d, 1H, J 5
13.7 Hz); 13C NMR (100.6 MHz, CDCl3) d 1.4 (–SiCH3), 61.6,
65.9, 133.9 (Si–CHLCH–C(O)–), 150.5 (Si–CHLCH–C(O)–),
167.0 (–COO–); IR (neat) 3336, 2949, 2894, 1720, 1244, 1204,
1175, 836, 687, 621 cm21. MS (FAB) m/z 363 ((M + H)+); exact
mass (M + H)+ 363.1658 (calcd for C14H35O3Si4, 363.1663).
Hydrosilylation of tris(trimethylsilyl)silane (2) with alkynes
1 in neat condition was performed by the reported procedure.7
(Z)-2-Cyanoethyl 3-[tris(trimethylsilyl)silyl]propenoate (3d).
(Yield 94%) (Rf 5 0.15, hexane–ethyl acetate 5 10 : 1):
Colorless oil; 1H NMR (400 MHz, CDCl3) d 0.18 (s, 27H),
2.72 (t, 2H, J 5 6.4 Hz), 4.32 (t, 2H, J 5 6.4 Hz), 6.61 (d, 1H,
J 5 13.7 Hz), 6.87 (d, 1H, J 5 13.7 Hz). 13C NMR (100.6 MHz,
CDCl3) d 1.38 (–SiCH3), 18.17 (–CH2–CN), 58.30 (–CH2–O–
C(O)–), 116.90 (–CN), 133.23 (–SiCHLCH–C(O)–), 152.00
(–SiCHLCH–C(O)–), 165.89 (–COO–); IR (neat) 2949, 2893,
2256, 1725, 1581, 1357, 1244, 1200, 1168, 1036, 837, 688,
621 cm21. MS (EI) m/z 371 (M+); exact mass M+ 371.1595
(calcd for C15H33NO2Si4, 371.1588).
(Z)-3-[Tris(trimethylsilyl)silyl]acrylonitrile (3k). (Yield 85%)
1
(Rf 5 0.1, hexane–ether 5 50 : 1): Colorless wax; H NMR
(400 MHz, CDCl3) d 0.26 (s, 27H), 6.09 (d, 1H, J 5 15.1 Hz),
6.94 (d, 1H, J 5 15.1 Hz). 13C NMR (100.6 MHz, CDCl3) d
1.19 (–SiCH3), 113.71 (–CN), 119.25 (–SiCHLCH–CN), 155.77
(–SiCHLCH–CN); IR (neat) 2951, 2895, 2214, 1400, 1246, 836,
721, 689, 622 cm21; MS (EI) m/z 299 (M+); exact mass M+
299.1376 (calcd for C12H29NSi4, 299.1377).
NMR spectra of (Z)-2-phenyl-1-[tris(trimethylsilyl)silyl]-
ethene (3l) were in accord with the reported data.29
(Z)-Octadecyl 3-[tris(trimethylsilyl)silyl]propenoate (3e).
(Yield 63%) (Rf 5 0.5, hexane): Colorless oil; 1H NMR
(400 MHz, CDCl3) d 0.18 (s, 27H), 0.88 (t, 3H, J 5 6.9 Hz),
1.26 (broad, 30H), 1.63 (m, 2H), 4.09 (t, 2H, J 5 6.8 Hz), 6.58
(d, 1H, J 5 13.7 Hz), 6.72 (d, 1H, J 5 13.7 Hz). 13C NMR
(100.6 MHz, CDCl3) d 1.41 (–SiCH3), 14.22, 22.79, 26.03,
28.89, 29.38, 29.46, 29.61, 29.68, 29.76, 29.77, 29.80, 32.03,
64.12, 134.80 (–SiCHLCH–C(O)–), 148.38 (–SiCHLCH–C(O)–),
166.69 (–COO–); IR (neat) 2925, 2854, 1717, 1243, 1205,
1175, 836, 621 cm21; MS (EI) m/z 570 (M+); exact mass M+
570.4147 (calcd for C30H66O2Si4, 570.4140); Anal. Calcd
for C30H66O2Si4: C, 63.08; H, 11.65. Found: C, 63.15; H,
11.71%.
(Z)-2-(4-Trifluoromethyl)phenyl-1-[tris(trimethylsilyl)silyl]-
1
ethene (3m). (Yield 83%) (Rf 5 0.7, hexane): Colorless oil; H
NMR (400 MHz, CDCl3) d 0.14 (s, 27H), 6.07 (d, 1H, J 5
14.6 Hz), 7.42 (d, 1H, J 5 14.6 Hz), 7.45 (d, 2H, J 5 8.2 Hz),
7.57 (d, 2H, J 5 8.2 Hz); 13C NMR (100.6 MHz, CDCl3) d 1.3
(–SiCH3), 124.3 (q, JC–F 5 271.6 Hz), 125.3 (q, JC–F 5 3.8 Hz),
128.1 (Si–CHLCH–), 128.3, 129.2 (q, JC–F 5 32.8 Hz), 144.2,
144.9 (Si–CHLCH–); 19F NMR (376.3 MHz, CDCl3) d 267.9;
IR (neat) 2951, 2895, 1618, 1327, 1246, 1167, 1130, 1109, 1167,
836, 688, 623 cm21. MS (EI) m/z 418 (M+); exact mass M+
418.1623 (calcd for C18H33F3Si4, 418.1611).
(Z)-2-(4-Fluorophenyl)-1-[tris(trimethylsilyl)silyl]ethene (3n).
(Yield 77%) (Rf 5 0.7, hexane): Colorless oil; 1H NMR
(400 MHz, CDCl3) d 0.13 (s, 27H), 5.88 (d, 1H, J 5 14.6 Hz),
7.00 (m, 2H), 7.31 (m, 2H), 7.36 (d, 1H, J 5 14.6 Hz);
13C NMR (100.6 MHz, CDCl3) d 1.3 (–SiCH3), 115.2 (d,
JC–F 5 21.4 Hz), 124.5 (Si–CHLCH–), 129.7 (d, JC–F 5 7.6 Hz),
(Z)-4-(Trifluoromethyl)benzyl 3-[tris(trimethylsilyl)silyl]pro-
penoate (3f). (Yield 78%) (Rf 5 0.55 (hexane–ether 5 50 : 1)):
Colorless oil; 1H NMR (400 MHz, CDCl3) d 0.16 (s, 27H),
5.19 (s, 2H), 6.65 (d, 1H, J 5 13.7 Hz), 6.84 (d, 2H, J 5
13.7 Hz), 7.49 (d, 1H, J 5 7.9 Hz), 7.61 (d, 1H, J 5 7.9 Hz).
13C NMR (100.6 MHz, CDCl3) d 1.37 (–SiCH3), 64.91
(Ar–CH2–), 124.13 (q, CF3, JC–F 5 272.6 Hz), 125.50 (q,
JC–F 5 3.8 Hz), 128.40, 130.33 (q, JC–F 5 32.8 Hz), 133.80
(–SiCHLCH–C(O)–), 140.47, 150.90 (–SiCHLCH–C(O)–),
166.15 (–COO–); IR (neat) 2950, 2894, 1723, 1623, 1580,
1326, 1244, 1167, 1132, 1068, 838 cm21. MS (EI) m/z 476 (M+);
exact Mass M+ 476.1672 (Calcd for C20H35F3O2Si4, 476.1666).
136.8 (d, JC–F 5 3.1 Hz), 145.3 (Si–CHLCH–), 162.1 (d, JC–F
5
246.4 Hz); 19F NMR (376.3 MHz, CDCl3) d 2115.3; IR (neat)
2950, 2894, 1603, 1505, 1245, 1155, 836, 746, 687, 617 cm21
MS (EI) m/z 368 (M+); exact mass M+ 368.1645 (calcd for
.
C17H33FSi4, 368.1643).
2. Si (111) surface modification
For XPS spectra measurements, single-crystal n-Si (111)
wafers (resistivity of 1–5 V cm and thickness of 825 ¡
25 mm), polished on one side, were used. They were cut into
pieces of about 10 6 10 mm2 in area. For ATR-IR measure-
ments, single-crystal n-Si (111) wafers, polished on both sides
(Z)-tert-Butyl 3-[tris(trimethylsilyl)silyl]propenoate (3h).
(Yield 91%) (Rf 5 0.65, hexane): Colorless oil; 1H NMR
(400 MHz, CDCl3) d 0.17 (s, 27H), 1.46 (s, 9H), 6.49 (d, 1H,
J 5 13.4 Hz), 6.66 (d, 1H, J 5 13.4 Hz); 13C NMR (100.6
MHz, CDCl3)
d 1.4 (–SiCH3), 28.3 (–C(CH3)3), 79.7
This journal is ß The Royal Society of Chemistry 2005
J. Mater. Chem., 2005, 15, 4906–4913 | 4911