Synthesis and Properties of Mixed Ligand Complexes of Diorganotin (IV): Part (V): Synthesis and Characterisation of Antifungal Acetylacetonato Diorganotin (IV)-O-Alkyl Trithiophosphates

Abstract

Some antifungal mixed ligand complexes of the type R ₂ Sn[SSH(S)POR′] [MeCOCHCOMe] have been synthesised by the reactions of diorganotin dichloride, R ₂ SnCl ₂ (R = Me, Bu, Ph) with acetyl acetone and O-alkyl trithiophosphates, R′OPS ₃ K ₂ (R′ = Me, Et, Pr ⁱ , Bu ⁱ , Ph) in 1:1:1 molar ratio in refluxing benzene. The products formed are monomeric, light yellow colored crystalline solids, soluble in common organic solvents and exhibit high sensitivity towards atmospheric moisture. The complexes have been characterised by elemental analysis (S,Sn), molecular weight measurements, IR and NMR ( ^I H, ³¹ P, ¹¹⁹ Sn) spectral studies. On the basis of spectral studies, it is postulated that acetyl acetonate and O-alkyl trithiophosphate moieties are bidentate and tin is hexacoordinated in nature. On the basis of ¹¹⁹ Sn NMR spectral studies, it is postulated that an equilibrium, with the results of disproportion is established. It is observed that when these compounds are applied in the form of dilute solution to various concentrations, they show their effectiveness against powdery mildew disease at a fixed interval of days.

Keywords:

• Acetyl acetone
• dialkyltin dichloride
• O-alkyl trithiophosphates

Leena Chordia is thankful to C.S.I.R., New Delhi for Financial Assistance as J.R.F. and S.A.I.F. (C.D.R.I.), Lucknow for spectral analysis.