STRUCTURAL CHEMISTRY OF ORGANOTIN CARBOXYLATES .8. SYNTHESIS AND SPECTROSCOPIC PROPERTIES OF DIORGANOTIN(IV) COMPLEXES WITH THIOPHENOXYACETIC ACID - X-RAY CRYSTAL-STRUCTURES OF [NORMAL-PR2SN(O2CCH2SPH)2] AND ([R2SN(O2CCH2SPH)]2O)2,R=NORMAL-PR, NORMAL-BU

Two types of diorganotin(IV) complexes i.e. [R2Sn(O2CCH2SPh)2] (1-5) and {[R2Sn(O2CCH2SPh)2-O}2 (6-10), R = Me, Et, (n)Pr, (n)Bu and (n)Oct, have been prepared in 1 : 2 and 1 : 1 molar ratios (tin:ligand) by reacting diorganotin oxide with thiophenoxyacetic acid. Characterization of the complexes was achieved using IR and H-1 NMR spectroscopy and in the case of the (n)Pr and (n)Bu complexes, by X-ray diffraction methods. The 1:2 compounds are monomeric with the Sn atoms existing in skew-trapezoidal planar geometries with asymmetrically coordinating carboxylate ligands and C-Sn-C angles of 136.7(2) and 140.7(2)-degrees respectively. The 1:1 compounds adopt the familar dicarboxylato tetraorganodistannoxane structural mode. The structures feature two bidentate briding and two monodentate carboxylate ligands, and both Sn atoms in the centrosymmetric dimers are in distorted trigonal bipyramidal geometries.