caa a22 4500 46907213X CHVBK 20180323132924.0 cr unu---uuuuu 170328e19920601xx s 000 0 eng 10.1007/BF00678412 doi (NATIONALLICENCE)springer-10.1007/BF00678412 Conformational behavior of nonfused biheterocycles: Part XVI. Isomeric phenyl-tetrazines and bitetrazines [Elektronische Daten] [Nino Russo, Marirosa Toscano] We present here an ab-initio STO-3G and advanced semiempirical AM1 calculation for the structure and the conformational behavior of phenyltetrazine and bitetrazine molecules. Results for phenyltetrazine isomers show that in the absence of H-H interactions, the preferred conformation is the planar one. Instead, in the case of bitetrazines, the systems dominated by the lone pair-lone pair interactions are not planar. In the presence of direct H-H interaction as for 5-5′-1,2,3,4 bitetrazine, the antiplanar conformation is the preferred one. Comparison with other systems (including one or more nitrogen lone pairs) shows that the compounds with the same ortho substituents have very similar conformational behavior irrespective of their composition. The AM1 results indicate that this method is able to give reliable conformational information for compounds in which H-H interactions are involved. A Fourier expansion of the torsional potential suggests that the first two terms fit the calculated torsional potentials well except in the case of two H-H interactions in the same molecule. Plenum Publishing Corporation, 1992 Russo Nino Dipartimento di Chimica, Universita'della Calabria, Arcavacata di Rende (CS), 1-87030, Italy aut Toscano Marirosa Dipartimento di Chimica, Universita'della Calabria, Arcavacata di Rende (CS), 1-87030, Italy aut Structural Chemistry Kluwer Academic Publishers 3/3(1992-06-01), 163-168 1040-0400 3:3<163 1992 3 11224 https://doi.org/10.1007/BF00678412 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00678412 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Russo Nino Dipartimento di Chimica, Universita'della Calabria, Arcavacata di Rende (CS), 1-87030, Italy aut NATIONALLICENCE 700 1- Toscano Marirosa Dipartimento di Chimica, Universita'della Calabria, Arcavacata di Rende (CS), 1-87030, Italy aut NATIONALLICENCE 773 0- Structural Chemistry Kluwer Academic Publishers 3/3(1992-06-01), 163-168 1040-0400 3:3<163 1992 3 11224 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer