Structural and molecular orbital study of the furazan N-oxide system. Structures of 3-amino-4-methylfurazan N-oxide and 4-amino-3-methylfurazan N-oxide, and molecular orbital calculations

Abstract

The molecular structure of the two title furazan oxide isomers has been determined by three-dimensional X-ray analysis from diffractometer data. Molecular orbital calculations at ab-initio level, using minimal and spilit valence basis sets and at semiempirical level using the MINDO/3 approach, have been performed on 3-amino-4-methylfurazan N-oxide, 4-amino-3-methylfurazan N-oxide, 3-methyl-4-aminofurazan, 3,4-diaminofurazan, and unsubstituted furazan and furazan N-oxide. The influence of the amino substituent on the five-membered ring has been analysed; all results show that significant electronic effects are present.