Structure and valence isomerization of antiaromatic molecules. XII. Nature of the instability of tetrazete and hexazine: cyclic conjugation /sigma/-system

Journal Article · Fri Jun 10 04:00:00 EDT 1988 · J. Org. Chem. USSR (Engl. Transl.); (United States)

OSTI ID:5949707

Simkin, B Ya; Glukhovtsev, M N; Minkin, V I

The instability of tetrazete N/sub 4/ and hexazine N/sub 6/ relative to their hydrocarbon analogs, namely, cyclobutadiene and benzene, was explained on the basis of the concepts introduced the cycled conjugation /sigma/-system. The consideration of only the /pi/-electron cyclic conjugation system does not permit the revelation of the differences in the stability of these compounds. The orbital analysis was supported by calculations of the resonance energies taking account of the /sigma/-electron energy, heats of homodesmic reactions, and heats of the cyclodecomposition reactions. According to the results of MNDO and ab initio (4-31G and 6-31G*) calculations, the ground state of tetrazete is a singlet (the D/sub 2h/ structure and bond length alternation is more stable than the T/sub d/ structure of tetraazatetrahedrane N/sub 4/). The different types of distortions of the D/sub 4h/ geometric configuration of the singlet state of tetrazete to the rectangular D/sub 2h/ geometric configuration of the singlet state of tetrazete to the rectangular D/sub 2h/ configuration were examined. An MNDO calculation of the resonance energy showed that tetrazete has greater antiaromatic nature than cyclobutadiene, while hexazine is a nonaromatic compound.

• Research Organization: M.A. Suslov Rostov State Univ. (USSR)
• OSTI ID: 5949707
• Journal Information: J. Org. Chem. USSR (Engl. Transl.); (United States), Journal Name: J. Org. Chem. USSR (Engl. Transl.); (United States) Vol. 24:1; ISSN JOCYA
• Country of Publication: United States
• Language: English

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
ALKENES
AROMATICS
ATOMIC MODELS
AZINES
BENZENE
BINDING ENERGY
CHEMICAL REACTIONS
COMPARATIVE EVALUATIONS
COMPUTERIZED SIMULATION
CONFIGURATION INTERACTION
CORRELATIONS
CYCLOALKENES
DISSOCIATION HEAT
ELECTRON CORRELATION
ELECTRONIC STRUCTURE
ENERGY
ENERGY LEVELS
ENTHALPY
EXCITED STATES
HETEROCYCLIC COMPOUNDS
HYDROCARBONS
INSTABILITY
ISOMERIZATION
MATHEMATICAL MODELS
MECHANICS
MOLECULAR MODELS
MOLECULAR ORBITAL METHOD
MOLECULAR STRUCTURE
MULTIPLETS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PHYSICAL PROPERTIES
QUANTUM MECHANICS
REACTION HEAT
SIMULATION
STRUCTURAL CHEMICAL ANALYSIS
THERMODYNAMIC PROPERTIES
TRIPLETS
VALENCE