Abstract:
Couplings involving Si atoms in H2SiCH2 and H2SiSiH2 were analysed in order to investigate the influence of a CSi or SiSi double bond at the INDO level of approximation. It was found that the restricted Hartree-Fock ground-state wavefunction is close to a non-singlet instability. As a consequence the calculated coupling constants are unreliable. To overcome this problem the SPPA approximation of the polarization propagator was used. An IPPP-CLOPPA analysis was performed in order to determine the origin of the problem. It was found that the "quasi-instability" is due to the vacant π orbital and the antibonding Si-H orbitals. © 1990.
Referencias:
- de Azua, Diz, Giribet, Contreras, Rae, A polarization propagator analysis of through-space spin-spin coupling constants:19F-19F couplings (1986) International Journal of Quantum Chemistry, 20 S, p. 585
- Diz, de Azua, Giribet, Contreras, The use of localized molecular orbitals and the polarization propagator to identify transmission mechanisms in nuclear spin-spin couplings (1990) International Journal of Quantum Chemistry, 37, p. 663
- Oddershede, (1978) Advances in Quantum Chemistry, 11. , P.O. Löwdin, Academic Press, New York
- Löwdin, (1965) Phys. Rev., Ser. A, 139, p. 357
- Webb, Nuclear Magnetic Resonance (1989) Specialist Periodical Reports, 18. , See, for example
- Beer, Grinter, (1977) J. Magn. Reson., 26, p. 421
- Beer, Grinter, (1978) J. Magn. Reson., 31, p. 187
- Blizzard, Santry, (1971) J. Chem. Phys., 55, p. 950
- Chambaud, Levy, Millie, (1978) Theor. Chim. Acta (Berl.), 48, p. 103. , See, for example
- Scuseria, Contreras, Unrestricted Hartree-Fock instabilities in semiempirical CNDO/S and INDO/S calculations of spin-spin coupling constants (1981) Theoretica Chimica Acta, 59, p. 437. , See, for example
- Scuseria, Engelmann, Contreras, (1982) Theor. Chim. Acta, 61, p. 49. , See, for example
- Scuseria, Contreras, (1982) Chem. Phys. Lett., 93, p. 425
- Engelmann, Contreras, Transmission mechanisms of spin-spin coupling constants within theCHF approximation: Their study using inner projections of the polarization propagator (1983) International Journal of Quantum Chemistry, 23, p. 1033
- Linderberg, Jorgensen, Oddershede, Ratner, Self-Consistent Polarization Propagator Approximation as a Modified Random Phase Method (1972) The Journal of Chemical Physics, 56, p. 6213
- Santry, (1968) J. Am. Chem. Soc., 90, p. 3309
- Benson, Hudson, (1971) Theor. Chim. Acta, 23, p. 259
- Santry, Segal, (1967) J. Chem. Phys., 47, p. 158
- Marsh, Gordon, (1976) J. Mol. Struct., 31, p. 345
- Brook, Abdesaken, Gutekunst, Plavac, (1982) Organometallics, 1, p. 994
- Dauel, Kart, Poirier, Goddard, Csizmadia, (1972) J. Mol. Struct., 11, p. 371
- Interatomic Distances (1958) Special Publication Nos. 11
- Interatomic Distances (1965) Special Publication Nos. 11, 18. , Chemical Society, London
- Engelhardt, Radeglia, Kelling, Stendel, (1981) J. Organomet. Chem., 212, p. 51
Citas:
---------- APA ----------
Rgihini, R., Giribet, C.G., De Azua, M.C.R. & Contreras, R.H.
(1990)
. The use of the SPPA method for the semi-empirical analysis of indirect spin couplings in Si-containing compounds. Journal of Molecular Structure: THEOCHEM, 210(C), 199-204.
http://dx.doi.org/10.1016/0166-1280(90)80042-M---------- CHICAGO ----------
Rgihini, R., Giribet, C.G., De Azua, M.C.R., Contreras, R.H.
"The use of the SPPA method for the semi-empirical analysis of indirect spin couplings in Si-containing compounds"
. Journal of Molecular Structure: THEOCHEM 210, no. C
(1990) : 199-204.
http://dx.doi.org/10.1016/0166-1280(90)80042-M---------- MLA ----------
Rgihini, R., Giribet, C.G., De Azua, M.C.R., Contreras, R.H.
"The use of the SPPA method for the semi-empirical analysis of indirect spin couplings in Si-containing compounds"
. Journal of Molecular Structure: THEOCHEM, vol. 210, no. C, 1990, pp. 199-204.
http://dx.doi.org/10.1016/0166-1280(90)80042-M---------- VANCOUVER ----------
Rgihini, R., Giribet, C.G., De Azua, M.C.R., Contreras, R.H. The use of the SPPA method for the semi-empirical analysis of indirect spin couplings in Si-containing compounds. J. Mol. Struct. THEOCHEM. 1990;210(C):199-204.
http://dx.doi.org/10.1016/0166-1280(90)80042-M