Temperature dependence of the14N quadrupole resonance in some thermochromic and photochromic N-salicylideneanilines

Abstract

In order to throw some light on the nature of the OHN hydrogen bond and on the mechanism responsible for thermochromism and photochromism in some solid N-salicylideneanilines, the 14N quadrupole coupling constants of thermochromic salicylidene-3-chloroaniline, photochromic salicylidene-2-chloroaniline and of thermochromic 5′-chloro-salicylidene-aniline is determined by proton–nitrogen double resonance. Um die Natur der OHN-Wasserstoffbindung und den Mechanismus zu klaren, der fur die Thermochromie und Photochromie in einigen festen N-Salizyliden-Anilinen verantwortlich ist, werden die 14N-Quadrupolkopplungskonstanten von thermochromem Salizyliden-3-Chloroanilin, photochromem Salizyliden-2-Chloroanilin und thermochromem 5′-Chloro-Salizylidenanilin durch Proton–Stickstoff-Doppelresonanz bestimmt.