Calculation of 14N and 33S quadrupole coupling constants on optimized molecular structures of thiazole

N-14 and S-33 nuclear quadrupole coupling constants have been calculated for optimized molecular structures of thiazole. For nitrogen, the B3PW91/6-311+G (df, pd) model was used to calculate of the electric field gradients, and for sulfur, the B3LYP/6-311G (3df, 3p) model. The best results are obtained for the B3PW91/6-311G (2d, 2pd) optimized molecular structure. For this structure, the root mean square difference between the calculated and experimental nitrogen coupling constants is 3 kHz (0.14%), and that between the calculated and experimental sulfur coupling constants is 43 kHz (0.25%). Calculated coupling constants are given in the principal axes of both the inertia and coupling constant tensors. (C) 2001 Academic Press.