ISSN:
0192-8651
Keywords:
Computational Chemistry and Molecular Modeling
;
Biochemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Computer Science
Notes:
The four isomers of Si6 H6, hexasilabenzene (1), hexasilaprismane (2), hexasila-Dewar benzene (3), and tris-(disilanediyl) (4), have been investigated, using highly correlated wavefunctions in conjunction with a local pseudopotential approach. At the Hartree-Fock level 1 (D6h), 2 (D3h), and 3 (C2v) are established as minima by means of the harmonic vibrational frequencies. Inclusion of the most important correlation corrections via CI however, provokes a significant puckering of 1 resulting in a D3d structure, 7.1 kJ/mol below the planar conformer. The detailed analysis shows unambiguously that the propensity to puckering is due solely to the correlation contributions from the σ framework while correlation of the π electrons is of little relevance. Isomer 2 turns out to be the most stable of the investigated isomers lying 41 kJ/mol below 1 (D3d). Isomers 3 and 4 are more than 100 kJ/mol higher in energy. The Si—Si bond energies of 1 and 2 are determined as 251 and 176 kJ/mol, respectively.
Additional Material:
3 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jcc.540090514
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