VIBRATIONAL SPECTRA OF 3--THIONE

Vibrational spectra of 3-(adamantan-l-yl)-4-(2-propen-l-yl)-1H-1,2,4-triazole-5(4H)-thione ([C.sub.15][H.sub.21][N.sub.3]S), which was promising for drug development, were studied experimentally and theoretically. The geometric structure and normal modes of the molecule and its dimer were calculated using quantum-mechanical density functional theory. It was shown that the experimentally obtained vibrational spectra were due to dimeric [C.sub.15][H.sub.21][N.sub.3]S structures. This conclusion was confirmed by spectra of the isotopically substituted compound with a deuterated imine. Bands at 1496 and 1549 [cm.sup.-1] were identified as markers of dimer formation. Bands at 936 and 1244 [cm.sup.-1] were found to be markers of intermolecular interactions of adamantane fragments.