Mi. Knyazhansky et Av. Metelitsa, ON PHOTOCOLORED PRODUCT STRUCTURE OF PHOTOCHROMIC AZOMETHINES IN SOLUTIONS AND CRYSTALS, Molecular crystals and liquid crystals science and technology. Section A, Molecular crystals and liquid crystals, 246, 1994, pp. 315-318
Comparative data of the experimental and quantum-chemical investigatio
ns of the photochromic anils and model compounds lead to the conclusio
n about unusual ''twisted'' cis (with regard to C-N-bond) zwitterion N
+H-structure of photocolored form with nearly orthogonal Ar-C- and CH-
NH+-groups. This form is stabilized kinetically by the intermolecular
interactions in the rigid media and crystals.