Abstract:

The thiourea derivatives of 1,2,4-triazol-5-one and —thione play important roles in the innovation of pesticides. In order to investigate the structureactivity relationship of these compounds, the theoretical calculations were carried out by the density functional theory (DFT) with the B3LYP method at the 6-311G basis set. The optimized geometric parameters, atomic net charges, orbital energy and IR spectroscopic properties were studied. The relationship between the structures and the activities of these compounds were analyzed. The calculation results showed good agreements with the experimental results. The results indicated that the S(9) atom was found to be an active point in the studied thioureas, and the more the charges on S(9), the more active the compound will be.

Key words: density functional theory(DFT), thiourea, triazol, structure-activity relationship