Electronic structure and conformational properties of azines. Part 2. 2,5-Diacetyl-3,4-diazahexa-2,4-diene, a 2,3-diaza-1,3-diene with a synclinal conformation. An x ray crystallographic, He1 photoelectron spectroscopic, and MNDO study.
In: Journal of the Chemical Society, Perkin Transactions 2: Physical Organic Chemistry (1972-1999), (1987) ; Nr. 6, S. 761-765
Zeitschriftenaufsatz / Fach: Chemie
2,5-Diacetyl-3,4-diaza-2,4-hexadiene consists of two essentially planar halves that are twisted about each other by 102.7 Deg. Bond lengths and orbital energies indicate strong conjugation between the electron lone-pair of one nitrogen atom and the double bonds of the other half of the mol. The mol. structure and torsion around the N-N and C-C bonds have been studied by MNDO calcns. While the structure parameters are in reasonable agreement with exptl. values, conformational properties are not treated adequately. According to these calcns. orbital energies are nearly invariant to conformational changes.