a Indian Institute of Science, Printed in India. Short Communication Solvent and substituent effects in the formation of Schiff bases

The formation constants of the Schiff bases formed between salicylaldehyde and substituted anilines in water-methanol and water-dioxan mixutres of varying composition have been determined spectro-photometrically. The formation constants of the bases except those formed with ortho-substituted anilines were found to decrease with the mole fraction of water in both the solvent media. A linear relationship was found between the log formation constants and the log dissociation constants of the conjugate acids of aniline studied. Here also the ortho-substituted anilines were found to be exceptions