Organotin(IV) derivatives as biocides: An investigation of structure by IR, solution NMR, electron impact MS and assessment of structure correlation with biocidal activity

A brief account is given of the synthesis, structural chemistry and the antibacterial, antifungal and cytotoxic effects of organotin complexes of 2-[(2,4-dichloroanilinocarbonyl)]benzoic acid. The unimolar and bimolar substitution products have been characterized by elemental analysis and spectral studies, including IR, H-1 NMR, C-13 NMR, Sn-119 NMR, and mass spectra. The data support the binding of the oxygen atom to the tin atom in [R2Sn(OOCR')(2)] and [R3Sn(OOCR')] (R = Me, Bu, and Ph, R' = 2-[(2,4-dichloroanilinocarbonyl)] benzoic acid). Based on these studies, with a coordination number of four, a distorted tetrahedral geometry has been proposed for the resulting derivatives in solution. The free ligand (R'COOH) and its respective tin complexes were tested in vitro against a number of microorganisms to assess their biocidal properties and to correlate them with the structures of the derivatives.