Evaluation of the ONIOM(B3PW91:HF) hybrid method for modeling butyltin chlorides

Abstract

AbstractThe ONIOM(B3PW91:HF) hybrid method has been evaluated for the purposes of modeling butyltin chlorides, XnSnCl4-n (X = n-butyl, sec-butyl, isobutyl, tert-butyl; n = 1, 2, 3). Three different partitioning schemes of a molecule within ONIOM(B3PW91:HF) were taken into account. For each of these partitioning schemes, conformational analyses of the XnSnCl4-n molecules were performed and then several molecular properties of the resulting rotamers were calculated. The values of molecular properties obtained by ONIOM(B3PW91:HF) were compared in a statistical manner with the reference values calculated by B3PW91. A careful choice of partitioning scheme for XnSnCl4-n allowed ONIOM(B3PW91:HF) to achieve a significant saving in computational cost, together with a relatively small decrease in the accuracy of the XnSnCl4-n molecular properties routinely obtained from conformational analysis (structural parameters, etc.). Unfortunately, the hybrid method turned out to be ineffective in reproducing the 1H, 13C and 119Sn NMR chemical shifts in XnSnCl4-n accurately.