Synthesis, Characterization, and In Vitro Antimicrobial Activities of Organotin(IV) Complexes of Schiff Bases with ONO-type Donor Atoms

A new series of diorganotin complexes of the type R2SnL (L-1: N-(2-hydroxy-5-chlorophenyl)-3-ethoxysalicylideneimine, R = Me, (Me2SnL1), R = n-Bu, (n-Bu2SnL1), R = Ph, (Ph2SnL1), L-2: N-(2-hydroxy-4-nitro - 5 - chlorophenyl) - 3 - ethoxysalicylideneimine, R = Ph, Ph2SnL2, L-3: N-(2-hydroxy-4-nitrophenyl)-3-methoxysalicylideneimine, R = Me, (Me2SnL3), R = n-Bu, (n-Bu2SnL3), L-4: N-(2-hydroxy-4-nitrophenyl) - 3 - ethoxysalicylideneimine, R = Me, (Me2SnL4), R = n-Bu, (n-Bu2SnL4)) were synthesized and characterized by elemental analysis, infrared (IR), H-1 and C-13 NMR mass spectroscopic techniques, and electrochemical measurements. Ph2SnL1 and Ph2SnL2 were also characterized by X-ray diffraction analysis and were found to show a fivefold C2NO2 coordination geometry nearly halfway between a trigonal bipyramidal and distorted square pyramidal arrangement. The C-Sn-C angles in the complexes were calculated using Lockhart's equations with the (1)J (Sn-117/119-C-13) and (2)J(Sn-117/119-H-1) values from the H-1 NMR and C-13 NMR spectra. Biocidal activity tests against several micro-organisms and some fungi indicate that all the complexes are mildly active against Gram (+) bacteria and the fungi, A. niger and inactive against Gram (-) bacteria. (C) 2010 Wiley Periodicals, Inc. Heteroatom Chem 21:373-385, 2010; View this article online at wileyonlinelibrary.com. DOI 10.1002/hc.20628