Study of charge transfer complexes of salicylidene aliphatic amines with Eu (fod)‎ 3 in cyclohexane by U. V. spectroscopy

Abstract EN

Salicylidene aliphatic amines in cyclohexane form 1 : 1 charge transfer complexes on addition of Eu (fod)3, indicated by the observation of a new band in their U.V.

spectra located at longer wavelength (= 400 nm) and with low extinction coefficient.

The coulorless solutions of Schiff-bases were changed to yellow on complexation with the shift reagent Eu(fod)3.

Equilibrium Constant values (K) for the complexes were obtained by applying Benesi-Hildebrand equation.

The factores which affected the values of of K like the charge on N, O & C (ChN, ChO, ChC), steric energy, O-N distance, the dihedral angles (dh1 and dh2) were established computationaly and were inserted into an equation of multiple linear regression as independent variables with K as dependet variable : K = -1288.

806-1653.

722ChN-40.

197ChO-914.

560ChC+507.

207(O-N dist.) From the equation it is seen that the most effective factor is ChN which means that increasing ChN causes more availability of the lone pair of electrons on nitrogen which facilitate the interaction with Eu(fod)3 and thus leading to higher K-value.