The reaction of dimethyltin(IV) dichloride with thiamine diphosphate (H2TDP): Synthesis and structure of [SnMe2(HTDP)(H2O)]Cl.H20, and possibility of a hitherto unsuspected role of the metal cofactor in the mechanism of vitamin-B1-dependent enzymes

The synthesis of the new thiamine diphosphate derivative [SnMe2(HTDP)(H2O)]Cl.H2O, its structures in solid state and in water, and the results of the kinetic experiments are described. The resulting SnMe2-holoen-zyme retains a significant proportion of the catalytic activity of the native enzyme despite the methyl groups on the metal atom.