Peculiarities of the manifestation of the K absorption bands in the UV absorption spectra of azomethine bases

The structure of the UV spectra of azomethine bases of the thiophene and dithienyl series was examined on the basis of the concept of the nonplanar structure of azomethine bases. A peculiarity of the manifestation of the K absorption bands associated with stabilization of the wavelengths of the K bands, which is determined by an increase in the angle of acoplanarity of the azomethine system above 30°, was revealed.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1043–1046, August, 1977.