Infrared and Raman Spectra of SBFL, BBPS, and BBPG
J. Phys. Chem. A, Vol. 102, No. 7, 1998 1145
References and Notes
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1
6
19, 751, 761, 1159, 1258, 1428, and 1590 cm . As shown
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1
in Figure 7 and Table 2, the IR intensity of 751 cm is invariant
with the change of the central atom. This is because the mode
involves only the out-of-plane C-H vibration; that is the Si-
C4 subunit is not in vibration. The IR intensity corresponding
(
(
1) Simmons, H. E.; Fukunaga, T. J. Am. Chem. Soc. 1967, 89, 5208.
2) Boschi, R.; Dreiding, A. S.; Heilbronner, E. J. Am. Chem. Soc.
1970, 92, 123.
(3) Hoffmann, R.; Imamura, A.; Zeiss, G. D. J. Am. Chem. Soc. 1967,
89, 5215.
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1
to 1590 cm is, however, enhanced since the Si-C4 vibration
involves the stretching and rocking modes.
(
(
4) Goldstein, M. J.; Hoffmann, R. J. Am. Chem. Soc. 1971, 93, 6193.
5) Bischof, P.; Gleiter, R.; Haider, R. J. Am. Chem. Soc. 1978, 100,
Bis(2,2′-biphenylene)germane. We could safely assign only
1036.
2
0
6 fundamentals. The uniform scaling factors of 0.900 and
.968 for HF/3-21G and B3LYP/3-21G, respectively, are the
(6) Kao, J.; Radom, L. J. Am. Chem. Soc. 1978, 100, 760.
(7) Gordon, M. D.; Fukunaga, T.; Simmons, H. E. J. Am. Chem. Soc.
best values to minimize the rms deviations of the experimental
fundamentals from theory.
1976, 98, 8401.
(
8) Semmelhack, M. F.; Foos, J. S.; Katz, S. J. Am. Chem. Soc. 1973,
9
1
1
5, 7325.
The rms deviations of computed frequencies from experiment
(9) Schweig, A.; Weidner, U.; Hellwinkel, D.; Krapp, W. Angew. Chem.
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1
turned out to be 22.90 and 15.43 cm for HF/3-21G and
B3LYP/3-21G, respectively.
973, 85, 360.
(10) Dantzig, N. A. v.; Piotrowiak, P.; Levy, D. H. Chem. Phys. Lett.
994, 223, 127.
a1 Modes. Among the 20 fundamentals, nine fundamentals
that we identify as a1 fundamentals are 275, 387, 675, 1035,
(
11) Dantzig, N. A. v.; Levy, D. H.; Vigo, C.; Piotrowiak, P. J. Chem.
Phys. 1995, 103, 4894.
12) Boo, B. H.; Choi, Y. S.; Kim, T.-S.; Kang, S. K.; Kang Y. H.;
-
1
1
119, 1231, 1287, 1563, and 1587 cm . The intensities of
(
the Raman bands at 675, 1035, 1119, 1231, 1463, 1563, and
Lee, S. Y. J. Mol. Struct. 1996, 377, 129.
(13) Stephens, P. J.; Devlin, F. J.; Chabalowski, C. F.; Frisch, M. J. J.
Phys. Chem. 1994, 98, 11623.
-1
1
587 cm listed in Table 2 are almost invariant with the change
of the central atom, indicating that the dipole changes do not
affect the Raman intensity.
a2 Modes. Identification of the a2 vibrational frequencies is
also impossible here since their modes are infrared and Raman
inactive.
(
14) Devlin, F. J.; Finley, J. W.; Stephens, P. J.; Frisch, M. J. J. Phys.
Chem. 1995, 99, 16883.
15) Handy, N. C.; Maslen, P. E.; Amos, R. D.; Andrews, J. S.; Murray,
(
C. W.; Laming, G. J. Chem. Phys. Lett. 1992, 197, 506.
(16) Handy, N. C.; Murray, C. W.; Amos, R. D. J. Phys. Chem. 1993,
7, 4392.
9
b1 Modes. Among the 10 fundamentals attributable to b1,
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1
(17) El-Azhary, A. A.; Suter, H. U. J. Phys. Chem. 1995, 99, 12751.
only one frequency, 275 cm , is identified as a b1 mode.
b2 Modes. Among the 20 b2 modes, only seven modes can
be identified. These are 681, 758, 1051, 1120, 1307, 1461, and
(
18) Wheeless, C. J. M.; Zhou, X.; Liu, R. J. Phys. Chem. 1995, 99,
1
2488.
(19) Rauhut, G.; Pulay, P. J. Phys. Chem. 1995, 99, 3093.
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1
1
1
570 cm . The IR intensities of fundamentals at 1120 and
(20) Johnson, B. G.; Gill, P. M. W.; Pople, J. A. J. Chem. Phys. 1993,
98, 5612.
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1
570 cm are enhanced since the Ge-C4 vibrations include a
(
(
(
(
(
(
21) Langhoff, S. R. J. Phys. Chem. 1996, 100, 2819.
Ge-C antisymmetric stretching mode.
22) Lee, S. Y.; Boo, B. H. J. Phys. Chem. 1996, 100, 8782.
23) Lee, S. Y.; Boo, B. H. J. Phys. Chem. 1996, 100, 15073.
24) Clarkson, R. G.; Gomberg, M. J. Am. Chem. Soc. 1930, 52, 2881.
25) Gilman, H.; Gorsich, R. D. J. Am. Chem. Soc. 1955, 77, 6380.
26) Gilman, H.; Gorsich, R. D. J. Am. Chem. Soc. 1958, 80, 1883.
e Modes. Among the 29 e fundamentals, nine fundamentals
are identified as the e mode. These are 447, 488, 618, 668,
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1
7
49, 1163, 1303, 1430, and 1585 cm . As shown in Figure 5
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1
and Table 2, the IR intensity of 749 cm is invariant with the
change of the central atom. However, the IR intensity of
fundamental at 1585 cm is increased due to the presence of
the low electronegative Ge atom.
(27) Frisch, M. J.; Trucks, G. W.; Schlegel, H. B.; Gill, P. M. W.;
Johnson, B. G.; Robb, M. A.; Cheeseman, J. R.; Keith, T.; Petersson, G.
A.; Montgomery, J. A.; Raghavachari, K.; Al-Laham, M. A.; Zakrzewski,
V. G.; Ortiz, J. V.; Foresman, J. B.; Cioslowski, J.; Stefanov, B. B.;
Nanayakkara, A.; Challacombe, M.; Peng, C. Y.; Ayala, P. Y.; Chen, W.;
Wong, M. W.; Andres, J. L.; Replogle, E. S.; Gomperts, R.; Martin, R. L.;
Fox, D. J.; Binkley, J. S.; Defrees, D. J.; Baker, J.; Stewart, J. P.; Head-
Gordon, M.; Gonzalez, C.; Pople, J. A. Gaussian 94, Revision C.2; Gaussian,
Inc.: Pittsburgh, PA, 1995.
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Acknowledgment. This work is supported by the Ministry
of Education, Korea, through the Basic Science Research
Institute Program, 1996-1997, Project No. BSRI-96-3432.
B.H.B. is grateful to Center for Molecular Science (CMS) for
partial financial support.
(28) Szczepanski, J.; Vala, M.; Talbi, D.; Parisel, O.; Ellinger, Y. J.
Chem. Phys. 1993, 98, 4494.