ISSN:
1089-7690
Quelle:
AIP Digital Archive
Thema:
Physik
,
Chemie und Pharmazie
Notizen:
Complete active space self-consistent field (CASSCF) and internally contracted single and double configuration interaction from the CASSCF reference functions (MR-SD-CI-CASSCF) methods have been used to calculate electronic and geometrical structures of low-lying 3A1, 3A2, 3B1, 3B2, and 1A1 states of methylene, MCH+2, and silylene, MSiH+2, complexes for M=Co+, Rh+, and Ir+. The ground state of CoCH+2, IrCH+2, and all considered MSiH+2 complexes is the nearly degenerate 3A1 and 3A2 states. For RhCH+2 the ground state is 1A1, with 3A1 and 3A2 states lying only 4–5 kcal/mol higher. The M+=CH2 bond is ∼10–20 kcal/mol stronger than the M+=SiH2 bond. Our best calculated binding energies are 80.3 for CoCH+2, 78.3 for RhCH+2, 113.1 for IrCH+2, 61.5 for CoSiH+2, 69.3 for RhSiH+2, and 98.7 kcal/mol for IrSiH+2, which are in general in good agreement with experimental values. By using the MC/LMO/CI technique has been shown that all present silylene complexes have mostly Fischer-type character with donor-acceptor σ and π bond. In contrary, the analogous methylene complexes are mostly Schrock-type complexes with covalent σ and π bond, except 3A1, 3B2, and 3B1 states of RhCH+2, which have mostly Fischer-type character.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1063/1.465664
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