Diorganotin(IV) complexes of flexible N-protected amino acids and ketoximes: preparation and structure - antimicrobial activity relationship

Diorganotin(IV) complexes of flexible N-protected amino acids and ketoximes having the compositions Me2Sn [C(O)C6H4C(O)NCHRCOO][ON = C6H10] (where R = -CH2CH(CH3)(2), -CH(CH3)C2H5,-CH2C6H5, -CH(CH3)(2)) and Me2Sn[C(O)C6H4C(O)NCHRCOO] [ON=CR'R ''] (where R = -CH2CH(CH3)(2), -CH(CH3)C2H5, -CH2C6H5, R' = R '' = CH3; R = -CH(CH3)C2H5, -CH2C6H5, -CH(CH3)(2), R' = CH3, R '' = C6H5) were prepared by the reaction of dimethyltin(IV) dichloride with sodium salts of flexible N-protected amino acids and ketoximes in 1:1:1 molar ratio in refluxing dry benzene. The synthesized complexes were characterized by elemental analyses and IR, multinuclear NMR (H-1, C-13, and Sn-119), and mass spectral studies. Plausible structures of these complexes have been suggested on the basis of molecular weight measurements and spectral data. Sn-119 NMR spectral data indicate the presence of pentacoordinated tin centres in these complexes. Some of the synthesized complexes and their ligands were also screened for their in vitro antimicrobial activity.