Studies on Colour and Constitution: Applications of Forster's Rule

Relative acidities and basicities of a series of heterocyclic nuclei have been evaluated with the help of absorption maxima data of the following groups of compounds:

  (i) Dimethin merocyanines and their aza analogues.

 (ii)  p-Dialkylaminobenzylidene derivatives of ketomethylene compounds and their aza analogues.

 (iii)  p-Dialkylaminostyryl dyes and their aza analogues.

 (iv) Unsymmetrical cyanines and their aza analogues