Synthesis and characterization of the first diorganotin(IV) complexes containing mixed arylazobenzoic acids and having skew trapezoidal bipyramidal geometry

Three diorganotin(IV) complexes of the type, [R2Sn(LaH)(LbH)] (R = nBu or Me and, LaH and LbH are two different 5-[(E)-2-(aryl)-1-diazenyl]-2-hydroxybenzoate residues; a: aryl = 4′-Cl-(held constant) and b: aryl = 4′-Me or 4′-Br) have been prepared either by reacting nBu2SnO, LaHH′ and LbHH′ (1:1:1) in anhydrous toluene or by reacting Me2SnCl2, LaHNa and LbHNa (1:1:1) in anhydrous methanol. The products were characterized by microanalysis, IR, NMR (1H, 13C, 119Sn) and 119mSn Mössbauer spectroscopy. A full characterization of the structures of the complexes [nBu2Sn(LaH)(LbH)] (1 and 2) and [Me2Sn(LaH)(LbH)] (3) in the solid state were accomplished by single crystal X-ray crystallography. These complexes were found to adopt the usual dicarboxylato structural type with a skew-trapezoidal bipyramidal arrangement around the tin atom.