title: Solvatochromism and preferential solvation of 1,4-dihydroxy-2,3-dimethyl-9,10-anthraquinone by UV-vis absorption and laser-induced fluorescence measurements.
abstract: Solvation characteristics of 1,4-dihydroxy-2,3-dimethyl-9,10-anthraquinone (1) in pure and binary solvent mixtures have been studied by UV-vis absorption spectroscopy and laser-induced fluorescence techniques. The binary solvent mixtures used as CCl(4) (tetrachloromethane)-DMF (N,N-dimethylformamide), AN (acetonitrile)-DMSO (dimethylsulfoxide), CHCl(3) (chloroform)-DMSO, CHCl(3)-MeOH (methanol), and MeOH-DMSO. The longest wavelength band of 1 has been studied in pure solvents as well as in binary solvent mixtures as a function of the bulk mole fraction. The Vis absorption band maxima show an unusual blue shift with increasing solvent polarity. The emission maxima of 1 show changes with varying the pure solvents and the composition in the case of binary solvent mixtures. Non-ideal solvation characteristics are observed in all binary solvent mixtures. It has been observed that the quantity [nu (12)-(X(1)nu (1)+X(2)nu (2))] serves as a measure of the extent of preferential solvation, where nu and X are the position of band maximum in wavenumbers (cm(-1)) and the bulk mole fraction values, respectively. The preferential solvation parameters local mole fraction (X(2)(L)), solvation index (delta(s2)), and exchange constant (k(12)) are evaluated.
authors: Department of Laser Studies, School of Physics, Madurai Kamaraj University, Madurai 625021, India.
authors: V
authors: V
authors: Sasirekha
authors: P
authors: P
authors: Vanelle
authors: T
authors: T
authors: Terme
authors: V
authors: V
authors: Ramakrishnan
mesh_terms: D000880:Anthraquinones / Q000737:chemistry*; D007834:Lasers; D015394:Molecular Structure; D012997:Solvents; D013050:Spectrometry, Fluorescence; D013053:Spectrophotometry; D013056:Spectrophotometry, Ultraviolet
chemical_list: D000880:Anthraquinones; D012997:Solvents