Infrared study on solvent-solute interactions of 2-acetylthiophene in binary mixtures

The infrared absorption spectra of the carbonyl stretching vibrations of 2-acetylthiophene (AcTh) have been investigated in cyclo-hexane/alcohol mixtures (C6H12/C2H5OH; C6H12/n-C4H9OH; C6H12/i-C3H7OH and C6H12/t-C5H11OH). Five types of carbonyl stretching vibration bands for AcTh are found with the change of the mole fraction of the aprotic solvent C6H12 (x(C6H12)) in binary solvent mixtures. The dependencies of the frequencies of carbonyl stretching vibrations (v(C=O)) on x(C6H12) allow a distinction and assignment of all species resulting from the solvent-solute interactions. Linear correlations between the v(C=O) of each species and x(C6H12) are found. The influence on the transformation of some species caused by the self association of alcohols is discussed. (C) 2003 Elsevier B.V. All rights reserved.