Biocidal organotin compounds: Part 1. Preparation and characterization of triorganotin(IV) 4‐pyridyl‐ and 2‐pyrimidyl‐ thioacetates and the crystal structure of triphenyltin(2‐pyrimidylthioacetate)

Abstract

AbstractThe preparation and spectroscopic characterization of [R3Sn(O2CCH2SC5H4N‐4)], R == Ph, benzyl (Bz), cyclohexyl (c‐Hex) and n‐Bu, and of [R3Sn(O2CCH2SC4H3N2‐2,6)], R == Me, Ph and n‐Bu, are reported. The 2‐pyrimidyl compounds feature trigonal bipyramidal tin centres with trans‐R3SnO2 geometries as was confirmed by X‐ray crystallography for [Ph3Sn(O2CCH2SC4H3N2‐2,6)]. ¶ By contrast the 4‐pyridyl compounds have trigonal bipyramidal geometries in the solid state (arising from intermolecular Sn…N interaction) and tetrahedral geometries in solution. The biocidal activity of these compounds against the fungi Helminthosporium maydis (ITCC 2675) and H. oryzae (ITCC 2675), both of which damage crops such as maize and rice, shows promise. Encouraging is the observation that the compounds show no adverse phytotoxicity at concentrations to 10−3M.