Molecular Structure and Fungicidal Activity againstCeratocystis ulmi of the 1:1 Adducts of Triphenyltin Chloride and 2,3-Disubstituted Thiazolidin-4-ones

Abstract

Several 1:1 addition compounds between triphenyltin chloride and 2,3-disubstituted thiazolidin-4-one ligands have been synthesized. Their molecular structure has been deduced using far IR and Mössbauer spectroscopies. In addition, molecular modeling of several of the complexes was used to explain the variation of the quadrupole splitting values in the Mössbauer spectra. The structures of the complexes were determined to be trigonal-bipyramidal with the three phenyl groups in the equatorial plane. However, the phenyl groups are not co-planar, on the basis of the observation of both the Sn–C (phenyl) symmetric and asymmetric stretching vibrations. The adducts were screened against the fungus Ceratocystis ulmi, the agent responsible for Dutch elm disease, and found to be effective in the inhibition of this fungus. The toxicity of the adducts varied with the hydrophobicity of the molecule. A direct correlation between substitution on the phenyl group on the thiazolidine ring and the toxicity of the compound was not observed.