caa a22 4500 467993084 CHVBK 20180323112550.0 cr unu---uuuuu 170328e19900801xx s 000 0 eng 10.1007/BF00480877 doi (NATIONALLICENCE)springer-10.1007/BF00480877 Cyclic aryleneazachalcogens: Synthesis, vibrational spectra, and π-electron structures [Elektronische Daten] [A. Zibarev, O. Fugaeva, A. Miller, S. Konchenko, I. Korobeinicheva, G. Furin] It is shown that a convenient general method for the synthesis of benzo-2,1,3-thiadiazole, its Se analog, their 4,5,6,7-tetrafluoro derivatives, and naphtho[1,8-c,d][1.2.6]thiadiazine is the reaction of the corresponding arylenediamines with chalcogen tetrahalides. A complete interpretation of the vibrational spectra of the synthesized compounds was obtained using the experimental shifts of the bands caused by the introduction of the 15N and 77Se isotopes into the compositions of the molecules and calculations of the frequencies and forms of the normal vibrations within the stretching-force field approximation. The peculiarities of the π-electron structures of the molecules of these substances were established by means of an analysis of the force constants of the CC, CN, NS, and NSe bonds and quantum-chemical calculations by the MNDO method: 1) The group π orbitals of the NXN fragments (X=S, Se) interact effectively with the group π orbitals of the carbocycles; 2) the p AO of nitrogen and sulfur make the principal contribution to the π MO of different symmetries (a2 and b1, respectively), as a consequence of which their π overlapping with one another is small, and the chemical bond within the limits of the NSN group is best described in the form of $$( - \mathop {\rm N}\limits^ - - \mathop {\text{S}}\limits^{\text{ + }} - {\text{N}} - {\text{)}}\begin{array}{*{20}c} \leftarrow & \to \\ \end{array} ( - {\text{N}} = \mathop {\text{S}}\limits^{\text{ + }} - \mathop {\rm N}\limits^ - - {\text{)}}$$ ; resonance; the same is also valid for the NSeN group; 3) on the whole, the π MO display a tendency for localization in individual molecular fragments. All of these factors decrease the aromatic character of the molecules. Plenum Publishing Corporation, 1991 Zibarev A. Novosibirsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR, 630090, Novosibirsk aut Fugaeva O. Novosibirsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR, 630090, Novosibirsk aut Miller A. Novosibirsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR, 630090, Novosibirsk aut Konchenko S. Novosibirsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR, 630090, Novosibirsk aut Korobeinicheva I. Novosibirsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR, 630090, Novosibirsk aut Furin G. Novosibirsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR, 630090, Novosibirsk aut Chemistry of Heterocyclic Compounds Kluwer Academic Publishers-Plenum Publishers 26/8(1990-08-01), 941-949 0009-3122 26:8<941 1990 26 10593 https://doi.org/10.1007/BF00480877 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00480877 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Zibarev A. Novosibirsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR, 630090, Novosibirsk aut NATIONALLICENCE 700 1- Fugaeva O. Novosibirsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR, 630090, Novosibirsk aut NATIONALLICENCE 700 1- Miller A. Novosibirsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR, 630090, Novosibirsk aut NATIONALLICENCE 700 1- Konchenko S. Novosibirsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR, 630090, Novosibirsk aut NATIONALLICENCE 700 1- Korobeinicheva I. Novosibirsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR, 630090, Novosibirsk aut NATIONALLICENCE 700 1- Furin G. Novosibirsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR, 630090, Novosibirsk aut NATIONALLICENCE 773 0- Chemistry of Heterocyclic Compounds Kluwer Academic Publishers-Plenum Publishers 26/8(1990-08-01), 941-949 0009-3122 26:8<941 1990 26 10593 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer