Abstract
A series of new ditriphenyltin(IV) dicarboxylate complexes of general formula (Ph3SnOOC-Pz)2R with Pz: pyrazole and R: alkyl or ether, have been synthesized from bipyrazoledicarboxylic acid and hydroxytripheyltin. These complexes, noted C1-C7, have been characterized by IR, 1 H and 13 C NMR spectroscopies. The molecular structures of C3: 1,3-Bis[(5-methyl-2-H-3-triphenyltincarboxylate pyrazol)]propane and C7: Bis[(2-methyl-2H-3triphenyltincarboxylate pyrazol)ethyl]oxide have been confirmed by single crystal X-ray diffraction. Both compounds crystallize in the monoclinic symmetry: C3 in P21 space group with a = 15.915(1) Å, b = 10.0791(8) Å, c = 13.823(1) Å, α = 90°, β = 100.459(3)°, γ = 90° and C7 in P21/n space group, with a = 15.0951(7) Å, b = 8.9847(3) Å, c = 34.244(1) Å, α = 90°, β = 101.421(2)°, γ = 90°.. The two cristallographically independent Sn1 and Sn2 atoms are tetra coordinated within distorted tetrahedral environments, very similar in the two compounds. The antifungal activity of these organotin complexes and their corresponding bipyrazoledicarboxylic acid (ligands) has been evaluated against the pathogenic Fusarium oxysporum f. sp. albedinis. This activity greatly depends on the nature of ligands and on the dose used. The presence of triphenyltin moiety improves considerably the antifungal activity becoming close to that of the benomyl (fungicide).