Theory predicts triplet ground-state organic silylenes [14]

Journal of the American Chemical Society

Volumn 121, Issue 11, 1999, Pages 2623-2624

  Holthausen, Max C ^a   Koch, Wolfram ^b   Apeloig, Yitzhak ^c  

^a HUMBOLDT UNIVERSITY   (Germany)

^b TECHNISCHE UNIVERSITÄT BERLIN   (Germany)

^c TECHNION ISRAEL INSTITUTE OF TECHNOLOGY   (Israel)

Author keywords

[No Author keywords available]

Indexed keywords

SILICON DERIVATIVE;

CALIBRATION; CONFORMATION; ELECTRON; ENERGY; LETTER; QUANTUM CHEMISTRY; QUANTUM THEORY;

EID: 0033599542     PISSN: 00027863     EISSN: None     Source Type: Journal    
DOI: 10.1021/ja9834935     Document Type: Letter

References (32)

1. For reviews, see: (a) Gaspar, P. P.; West, R. In The Chemistry of Organic Silicon Compounds II; Rappoport, Z., Apeloig, Y., Eds.; Wiley: Chichester, 1998; Chapter 43, pp 2463-2569. (b) Apeloig, Y. In The Chemistry of Organic Silicon Compounds; Patai, S., Rappoport, Z., Eds.; Wiley: Chichester, 1989; Chapter 2, pp 167-184.
2. For reviews, see: (a) Gaspar, P. P.; West, R. In The Chemistry of Organic Silicon Compounds II; Rappoport, Z., Apeloig, Y., Eds.; Wiley: Chichester, 1998; Chapter 43, pp 2463-2569. (b) Apeloig, Y. In The Chemistry of Organic Silicon Compounds; Patai, S., Rappoport, Z., Eds.; Wiley: Chichester, 1989; Chapter 2, pp 167-184.
3. For reviews, see: (a) Wentrup, C. Neutral Reactive Molecules; Wiley: New York, 1984. (b) Nefedov, O. M.; Egorov, M. P.; Ioffe, A. I.; Menchikov, L. G.; Zuev, P. S.; Minkin, V. I.; Simkin, B. Ya.; Glukhovtsev, M. N. Carbenes and Carbene Analogues; National Committee of Soviet Chemists, Moscow, "Nauka", 1991.
4. For reviews, see: (a) Wentrup, C. Neutral Reactive Molecules; Wiley: New York, 1984. (b) Nefedov, O. M.; Egorov, M. P.; Ioffe, A. I.; Menchikov, L. G.; Zuev, P. S.; Minkin, V. I.; Simkin, B. Ya.; Glukhovtsev, M. N. Carbenes and Carbene Analogues; National Committee of Soviet Chemists, Moscow, "Nauka", 1991.
5. (a) Luke, B. T.; Pople, J. A.; Krogh-Jespersen, M.-B.; Apeloig, Y.; Karni, M.; Chandrasekhar, J.; Schleyer, P. v. R. J. Am. Chem. Soc. 1986, 108, 270.
6. (b) Nyulászi, L.; Belghazi, A.; Kis-Szétsi, S.; Veszprémi, T.; Heinicke, J. J. Mol. Struct. (THEOCHEM) 1994, 313, 73.
7. (c) Gordon, M. S.; Bartol, D. J. Am. Chem. Soc. 1987, 109, 5948.
8. (a) Kasdan, A.; Herbst, E.; Lineberger, W. C. J. Chem. Phys. 1975, 62, 541.
9. (b) Berkowitz, J. L.; Green, J. P.; Cho, H.; Ruscic, R. J. Chem Phys. 1987, 86, 1235.
10. See, for example: (a) Bauschlicher, C. W., Jr.; Langhoff, S. R. J. Chem. Phys. 1987, 87, 387. (b) Balasubramanian, K.; McLean, A. D. J. Chem. Phys. 1986, 85, 5117. (c) Grev, R.; Schaefer, H. F., III. J. Chem. Phys. 1992, 97, 8389.
11. See, for example: (a) Bauschlicher, C. W., Jr.; Langhoff, S. R. J. Chem. Phys. 1987, 87, 387. (b) Balasubramanian, K.; McLean, A. D. J. Chem. Phys. 1986, 85, 5117. (c) Grev, R.; Schaefer, H. F., III. J. Chem. Phys. 1992, 97, 8389.
12. See, for example: (a) Bauschlicher, C. W., Jr.; Langhoff, S. R. J. Chem. Phys. 1987, 87, 387. (b) Balasubramanian, K.; McLean, A. D. J. Chem. Phys. 1986, 85, 5117. (c) Grev, R.; Schaefer, H. F., III. J. Chem. Phys. 1992, 97, 8389.
13. Rao, D. R. J. Mol. Spectrosc. 1970, 34, 284.
14. (a) Kalcher, J.; Sax, A. F. J. Mol. Struct. (THEOCHEM) 1992, 253, 287.
15. (b) Grev, R. S.; Schaefer, H. F., III. J. Am. Chem. Soc. 1986, 108, 5804.
16. (c) Gordon, M. S.; Schmidt, M. W. Chem. Phys. Lett. 1986, 132, 294.
17. Krogh-Jespersen, K. J. Am. Chem. Soc. 1985, 107, 537.
18. Grev, R. S.; Schaefer, H. F., III; Gaspar, P. P J. Am. Chem. Soc. 1991, 113, 5638.
19. (a) Colvin, M. E.; Schaefer, H. F., III; Bicerano, J. J. Chem. Phys. 1985, 83, 4581.
20. (b) Colvin, M. E.; Breulet, J.; Schaefer, H. F., III. Tetrahedron 1985, 41, 1429.
21. Gordon, M. S. Chem. Phys. Lett. 1985, 114, 348.
22. Boudjouk, U.; Samaraweera, R.; Sooriyakumaran, J.; Chrusciel Anderson, K. R. Angew. Chem., Int. Ed. Engl. 1988, 27, 1355.
23. (a) Ando, W.; Fujita, M.; Yoshida, H.; Sekiguchi, A. J. Am. Chem. Soc. 1988, 110, 3310.
24. (b) Zhang, S.; Wagenseller, P. E.; Conlin, R. T. J. Am. Chem. Soc. 1991, 113, 4278.
25. Pae, D. H.; Xiao, M.; Chiang, M. Y.; Gaspar, P. P. J. Am. Chem. Soc. 1991, 113, 1281.
26. These calculations have been performed with the program DGauss 2.3, Cray Research, Inc., 1994. The gradient corrected BLYP functional was used with a standard DZVP valence basis set and an effective core potential (ECP, see Chen, H.; Krasowski, M.; Fitzgerald, G. J. Chem. Phys. 1993, 98, 8710) on all non-hydrogen atoms. Even with this approximate method the calculations on the larger molecules required several hundred hours of CRAY-J90 time per optimization.
27. The B3LYP functional has been used as implemented in Gaussian 94, Gaussian, Inc., Pittsburgh, PA, 1995. Very high accuracy CCSD(T) calculations employing the correlation consistent polarized quadruple ζ basis set (cc-pVQZ, H. C: Dunning, T. H. J. Chem. Phys. 1989, 90, 1007; Si: Woon, D. E.; Dunning, T. H. J. Chem. Phys. 1993, 98, 1358) have been performed with Molpro 96 (see, for example: Knowles, P. J.; Hampel, C.; Werner, H.-J. J. Chem. Phys. 1993, 99, 5219 and references therein).
28. The B3LYP functional has been used as implemented in Gaussian 94, Gaussian, Inc., Pittsburgh, PA, 1995. Very high accuracy CCSD(T) calculations employing the correlation consistent polarized quadruple ζ basis set (cc-pVQZ, H. C: Dunning, T. H. J. Chem. Phys. 1989, 90, 1007; Si: Woon, D. E.; Dunning, T. H. J. Chem. Phys. 1993, 98, 1358) have been performed with Molpro 96 (see, for example: Knowles, P. J.; Hampel, C.; Werner, H.-J. J. Chem. Phys. 1993, 99, 5219 and references therein).
29. The B3LYP functional has been used as implemented in Gaussian 94, Gaussian, Inc., Pittsburgh, PA, 1995. Very high accuracy CCSD(T) calculations employing the correlation consistent polarized quadruple ζ basis set (cc-pVQZ, H. C: Dunning, T. H. J. Chem. Phys. 1989, 90, 1007; Si: Woon, D. E.; Dunning, T. H. J. Chem. Phys. 1993, 98, 1358) have been performed with Molpro 96 (see, for example: Knowles, P. J.; Hampel, C.; Werner, H.-J. J. Chem. Phys. 1993, 99, 5219 and references therein).
30. The structures of all of these silylenes were first optimized using the semiempiric AM1 method. At this level of theory a systematic search of the conformational space for rotation around the various bonds was carried out, i.e., all Si-Si and Si-C bonds were systematically rotated in steps of 120°, and subsequent geometry optimizations of all geometrical parameters (including dihedral angles) were carried out (several hundred conformations were calculated for each case). The structures lowest in energy for the singlet and for the triplet states of each silylene, which correspond to the global minima at this level of theory, were then submitted to geometry optimization at the DFT level. The conformational analyses were performed using the Spartan 3.0 program (Wavefunction, Inc., 18401 von Karman Ave., Irvine, CA 92715.)
31. Kira, M. (Tohoku University, Sendai, Japan), personal communication.
32. 3Si see: Gaspar, P. P.; Chen, T.; Haile, T.; Lei, D.; Lin, T. S.; Smirnov, A. I.; Winchester, W. R. The 31 Organosilicon Symposium, Tulane University, New Orleans, Louisiana, May 29-30, 1998, C-3.