Determination of ground and excited state dipole moments of 4,5'-diamino[1,1':3',1''-terphenyl]-4',6'-dicarbonitrile using solvatochromic method and quantum-chemical calculations.

Electronic absorption and fluorescence spectra of 4,5'-diamino[1,1':3',1''-terphenyl]-4',6'-dicarbonitrile (1) were recorded at room temperature in several solvents of different polarity. The results of spectroscopic measurements are analyzed using the theory of solvatochromism, based on a dielectric continuum description of the solvent and the classical Onsager cavity model. The difference in the excited and ground state dipole moments (mu(e)-mu(g)) of the molecule under study was estimated using methods applied by Bayliss, Ooshika, McRae, Lippert, Mataga, Bakhshiev and Kawski.