Quantum-chemical investigation of structure and valence isomerizations of perdehydrotetrasilacyclobutadiene
Journal Article
·
· Theor. Exp. Chem. (Engl. Transl.); (United States)
The structure and valence isomerizations of perdehydrotetrasilacyclobutadiene (Si/sub 4/) are discussed on the basis of concepts of cyclic ..pi..- and sigma-conjugation. Calculations by the MINDO/3 and MNDO methods established two types of geometric configurations with D/sub 4h/ symmetry for both the singlet and triplet states of perdehydrotetrasilacyclobutadiene, differing in inversion of the HOMO and LUMO. Neither D/sub 4h/ configuration of the singlet state corresponds to minima on the potential energy surface, and these configurations are distorted, one toward a rectangular structure with D/sub 2h/ symmetry with alternation of bond lengths in the ring, and the other toward a rhombic bicyclic structure with D/sub 2h/ symmetry. The latter structure corresponds to the global minimum on the potential energy surface of the Si/sub 4/.
- Research Organization:
- Rostov Univ., Rostov-on-Don (USSR)
- OSTI ID:
- 6478337
- Journal Information:
- Theor. Exp. Chem. (Engl. Transl.); (United States), Journal Name: Theor. Exp. Chem. (Engl. Transl.); (United States) Vol. 23:4; ISSN TEXCA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
657002 -- Theoretical & Mathematical Physics-- Classical & Quantum Mechanics
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ATOMIC MODELS
CHEMICAL REACTIONS
COMPUTERIZED SIMULATION
CONFIGURATION INTERACTION
DIENES
ELECTRONIC STRUCTURE
ENERGY LEVELS
EXCITED STATES
GROUND STATES
HYDROCARBONS
ISOMERIZATION
MATHEMATICAL MODELS
MECHANICS
MOLECULAR STRUCTURE
MULTIPLETS
OPTIMIZATION
ORGANIC COMPOUNDS
ORGANIC SILICON COMPOUNDS
POLYENES
QUANTUM MECHANICS
SIMULATION
TRIPLETS
VALENCE
400201* -- Chemical & Physicochemical Properties
657002 -- Theoretical & Mathematical Physics-- Classical & Quantum Mechanics
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ATOMIC MODELS
CHEMICAL REACTIONS
COMPUTERIZED SIMULATION
CONFIGURATION INTERACTION
DIENES
ELECTRONIC STRUCTURE
ENERGY LEVELS
EXCITED STATES
GROUND STATES
HYDROCARBONS
ISOMERIZATION
MATHEMATICAL MODELS
MECHANICS
MOLECULAR STRUCTURE
MULTIPLETS
OPTIMIZATION
ORGANIC COMPOUNDS
ORGANIC SILICON COMPOUNDS
POLYENES
QUANTUM MECHANICS
SIMULATION
TRIPLETS
VALENCE