I. C. Vasiliu, C. Constantinescu, M. Voicescu, A. Emandi, Solvent effects on the absorption and fluorescence spectra of Er(iii) (azo-dyes and schiff bases) complexes: determination of ground and excited state dipole moment, Dig. J. Nanomater Bios., 6/2 (2011) 603-608.

Title: Solvent effects on the absorption and fluorescence spectra of Er(iii) (azo-dyes and schiff bases) complexes: determination of ground and excited state dipole moment

Abstract: Absorption and fluorescence emission spectra of some thermally stable Er(III) mononuclear complexes of azo dyes, namely o, o' - dihydroxy azobenzene (DAB), o, o' - dihydroxy 4-Cl-phenylazonaphatalene (P1) and Schiff bases o, o' - dihydroxy phenylazomethinnaphatalene (D2), o- hidroxy - o' - carboxy (D3), were recorded in solvents with different solvent dielectric constant epsilon and refractive index n. The solvatochromic shift method was used to determine the experimental ground and excited state dipole moments of the complexes. All the complexes were proved to be more polar in the excited state as compared with the ground state.

Key words: Solvent effects; Fluorescence; Dipole moments; Erbium complexes; azo-dyes; azo-methin