Homolytic bond-dissociation enthalpies of tin bonds and tin-ligand bond strengths - A computational study

Density functional theory and second-order Moller-Plesset perturbation theory with effective core potentials have been used to calculate homolytic bond-dissociation enthalpies, D(Sn-X), of organotin compounds, and their performance has been assessed by comparison with available experimental bond enthalpies. The SDB-aug-cc-pVTZ basis set with its effective core potential was used to calculate the D(Sn-X) of a series of trimethyltin(IV) species, Me3Sn-X, where X = H, CH3, CH2CH3, NH2, OH, Cl, and F. This is the most comprehensive report to date of homolytic Sn-X bond- dissociation enthalpies (BDEs). Effective core potentials are then used to calculate thermodynamic parameters including donor-acceptor bond enthalpies, (D) over bar (Sn-X), for a series of tin-ligand complexes, L2SnX4 (X = Br or Cl, L = py, dmf, or dmtf), which are compared with previous experimental and nonrelativistic computational results. Based on computational efficiency and accuracy, it is concluded that effective core potentials are appropriate computational methods to examine bonding in organotin systems.