Absorption spectra of tetrahaloquinone-aza-aromatic systems

Abstract The characteristic charge transfer absorption bands of a number of aza-aromatics as donors with chloranil, bromanil and iodanil as acceptors have been measured in chloroform solution in the ultraviolet and visible regions. The bands in the ultraviolet and visible regions are attributed respectively to the charge transfer transition of π electron and n electron of donors to the vacant orbital of the acceptors. A number of more or less sharp bands presumed to be due to the singlet → triplet transition in donors has been observed in some cases with bromanil and iodanil.