Synthesis, Spectroscopic Characterization: (IR, Multinuclear NMR, ^119mSn Mössbauer and Mass Spectrometry), and Biological Activity (Antibacterial, Antifungal, and Cytotoxicity) of Di‐ and Triorganotin(IV) Complexes of (E)‐3‐(4‐Chlorophenyl)‐2‐phenylpropenoic Acid

Abstract

In an effort to develop new organotin(IV) compounds of industrial and biological importance, a series of di‐ and triorganotin(IV) complexes of (E)‐3‐(4‐chlorophenyl)‐2‐phenylpropenoic acid with the general formula R_4‐n SnL _n have been synthesized by the reaction of the corresponding organotin chlorides with the sodium salt of (E)‐3‐(4‐chlorophenyl)‐2‐phenylpropenoic acid (C₁₅H₁₀ClO₂Na) where, R = CH₃, C₂H₅, n‐C₄H₉, C₆H₅, C₆H₅ · CH₂, n = 1 or 2 and L = acid anion (C₁₅H₁₀ClO₂ ⁻). The dimeric tetraorganodicarboxylatodistannoxanes [(Me₂SnL)₂O]₂ compound (2) and [(Bu₂SnL)₂O]₂ compound (4), L = C₁₅H₁₀ClO₂ ⁻, were synthesized by the reaction of R₂SnO with the ligand acid (HL) in 1:1 molar ratio with azeotropic removal of water. The structures of the complexes are discussed on the basis of IR, multinuclear (¹H, ¹³C, ¹¹⁹Sn) NMR, ^119mSn Mössbauer spectroscopies and mass spectrometry. The spectroscopic results substantiate that all the diorganotin(IV) derivatives possess trigonal‐bipyramidal structures in solution and octahedral geometry in the solid state. A linear polymeric trigonal‐bipyramidal structure in the solid state and a tetrahedral environment around the tin atom in non‐coordinating solvents has been proposed for the triorganotin(IV) derivatives. The Δν [Δν = ν_asym(COO) − ν_sym(COO)] values obtained from the IR data, in comparison to the ligand acid and its sodium salt, fall in the range which shows that the ligand may act as a bidentate coordinating group through the carboxyl (COO) oxygen atoms. The biological activity and LD₅₀ data of the synthesized compounds are also reported. The triorganotin(IV) complexes exhibit significantly better activities than the diorganotin(IV) derivatives. The LD₅₀ data show that most of the investigated compounds are cytotoxic.

Keywords:

• Organotin(IV)
• Multinuclear NMR
• ^119mSn Mössbauer
• Biological activity
• (E)‐3‐(4‐Chlorophenyl)‐2‐phenylpropenoic acid

Acknowledgments

S.A. is thankful to the Quaid‐i‐Azam University, Islamabad, Pakistan, for financial support of this work. S.R. is grateful to the University of Azad Jammu and Kashmir, Muzaffarabad, for a study leave. Thanks are due to Professor B. Wrackmeyer, University of Bayreuth, Germany for providing facilities to collect multinuclear NMR and mass spectral data. Financial support for the Mössbauer studies from the National Institutes of Health, Minority Biomedical Support Program (MBRS/SCORE, GM08005) is gratefully acknowledged.