Solvatochromic effects in the absorption spectra of some azobenzene compounds

Solvatochromic behavior of some 4,4′-substituted azoaromatic derivatives has been investigated in solvents of different polarities. The solvent dependent UV/vis spectral shifts, νmax, were analyzed using some physical parameters such as refractive index, dielectric constant, Kamlet–Taft parameters α (hydrogen bond donating ability) and β (hydrogen bond accepting ability).The intermolecular interaction types in the azobenzene derivatives solutions were established on the basis of a multiple linear regression analysis. The fitting coefficients obtained from this analysis allowed us to estimate the contribution of each type of interactions to the total spectral shift in the studied solutions.