The investigation of solvatochromic behaviors, excited and ground state dipole moments of compounds which contains new mono Schiff base

The ability of Schiff base-containing compounds to have photochromic properties allows them to be used in imaging systems, optical computers, semiconductor technology, and organic electronics materials. In this study; The electronic structure, solvatochromism and electric dipole moment of four new Schiff base molecules titled as (E)-2-(2,5- dimethoxybenzylideneamino)phenol (S1), (E)-4-(3,4- dimethoxybenzylideneamino)phenol (S2), (E)-N-(2,4-dimethoxybenzyliden)benzeneamine (S3) and (E)-4-(2,4- dimethoxybenzylideneamino)phenol (S4) molecules were determined. The absorbance (UV) and fluorescence spectra of compounds containing Schiff base were measured at room temperature in 28 different solvents with different polarities. The UV spectra recorded in polar protic, apolar protic and nonpolar solvents, it is usually observed 3 bands and these bands were observed from the conjugation in the phenyl ring, the conjugation between the phenyl ring and the Schiff base group and electronic transitions in the Schiff base group. In the fluorescence spectra of the examined molecules, generally 2 bands were observed and it was seen that the band originated from delocalization of phenyl rings, conjugation in phenyl rings with Schiff base group and electronic transitions in Schiff base group. Solvent-solute interactions of the molecules were analyzed by using Kamlet-Taft solvatochromism and Catalan solvatochromism, which are Linear Solvation Energy Relationship (LSER) models. Using the values obtained from the Kamlet-Taft and Catalan solvatochromism, the quantities involved in solvent-solute interactions such as solvent polarity, solvent dipolarity, solvent acidity and solvent basicity, dispersion-induction interaction, dipolar-orientation interaction were compared with each other. In addition, experimentally optained frequency value are compared with theoretical values obtained by Kamlet-Taft and Catalan solvatochromism.The excited and ground state electric dipole moments are calculated by the methods of Lippert-Mataga, Bakhsiev, Bilot-Kawski and compared with experimental dipole moments. Keywords: Schiff base, Solvatochromism, Kamlet-Taft solvatochromism, Catalan solvatochromism, Electronic structure, Electric dipole moment.