ELECTRON STRUCTURE AND PHYSICAL-CHEMICAL PROPERTIES OF AZO COMPOUNDS .14. CONFORMATION OF BENZALANILINE

A re‐evaluation of the electronic spectra of benzalaniline (II), 3, 3‐dimethyl‐2‐phenyl‐indolenine (X), mono‐aryl substituted azomethines (XI, XIV, XV) and trimethylindolenine (XII) as well as of their conjugate acids strongly supports the hypothesis of ISMAILSKI & SMIRNOV [14] and of EBARA [15] that benzalaniline exists in a preferred peri‐perpendicular conformation. The same is true for N‐phenylazomethines. The n → π* transition of a ‘planar benzalaniline’ has been located at 27 600 cm−1 (ε ≈ 60). Copyright © 1968 Verlag GmbH & Co. KGaA, Weinheim