Synthesis,characterization and biological activity of diorganotin dithioate derivatives

Reaction of dithioacid (ArCS₂CH₂CO₂H, Ar = phenyl, 2‐furyl or 2‐thienyl) with ⁿBu₂SnO gives monomeric (ArCS₂CH₂CO₂)₂Sn(Buⁿ)₂ in a 2:1 molar ratio, and dimeric {(ArCS₂CH₂CO₂)Sn(Buⁿ)₂]₂O}₂ in a 1:1 molar ratio, respectively, which have been characterized by IR, NMR (¹H, ¹³C and ¹¹⁹Sn) spectra and elemental analyses. X‐ray crystal structure analyses indicate that the compound (C₄H₃S)CS₂CH₂CO₂]₂Sn(Buⁿ)₂ is monomeric with the tin atom occupying a skew‐trapezoidal bipyramidal geometry. In addition, this compound forms a three‐dimensional structure through the weak intermolecular S^…S and Sn^…O interactions. Compound {((C₄H₃S)CS₂CH₂CO₂)Sn(Buⁿ)₂]₂O}₂ is a centrosymmetric dimer with a cyclic Sn₂O₂ unit, in which the coordination modes of the two crystallographically unique carboxylic ligands are different. One acts as monodentate ligand by the carboxylate oxygen atom, the other bridges two tin atoms via only one carboxylate oxygen atom. Furthermore, each tin atom in this compound locates a distorted trigonal bipyramidal geometry. Biological activities of these organotin compounds show that they have hardly acaricidal activity, but display certain activities on fungi. In mononuclear tin compounds, the inhibition percentage of (C₄H₃S)CS₂CH₂CO₂]₂Sn(Buⁿ)₂ in vitro for Alternaria solani and Physolospora piricola is 57.1% and 43.9%, respectively, while in dimers {((C₄H₃O)CS₂CH₂CO₂)Sn(Buⁿ)₂]₂O}₂ shows high inhibition percentage for Gibbereila zeae (52.6%) and Physolospora piricola (50.0%), respectively. Copyright © 2006 John Wiley & Sons, Ltd.