Vibrational analysis of benzothiazoline-2-thione

Infrared and Raman spectra of solid benzothiazoline-2-thione (BTT) have bee n measured in the range 4000-50 cm(-1) and 4000-200 cm(-1), respectively. F orce constants and vibrational frequencies of BTT and 2-mercapto-benzothiaz ole have been determined by means of quantum chemical calculations on the b asis of the density functional theory. An assignment has been made for the normal vibrations using the calculated vibrational frequencies and the pote ntial energy distribution. In spite of the probability of the existence of 2-mercapto-benzothiazole within a tautomeric equilibrium, there is no indic ation of its presence besides the neat BTT. (C) 1999 Elsevier Science B.V. All rights reserved.