THE CHEMISTRY AND APPLICATIONS OF ORGANOTIN(IV) COMPLEXES OF PHOSPHORUS-BASED ACIDS

Synthesis, reactivity, structural aspects and applications of organotin(IV) complexes with phosphorus-based acids are reviewed. Complexes are classified according to the number of organic groups on tin and the nature of the donor atoms (oxygen and/or sulphur) on phosphorus. In general, organotin complexes of these acids are synthesized either by the reaction of organotin oxide with a free ligand or by treating the organotin halide with the alkali metal salt of an acid. Reactions of monoorganotin oxides with phosphorus-based acids proceed in a stepwise manner involving a variety of organotin clusters, some of which are now fully characterized. The structure of the organotin complexes of these ligands is influenced by the number of R groups on tin and the donor set of phosphorus (>PO2,>POS,>PS2). The >PO2-type ligands usually prefer bidentate bridging or a chelating bonding mode, while >PS2-type ligands bind an organotin moiety in a monodentate or chelating (asymmetric or symmetric) fashion. The application of these complexes as catalysts, corrosion inhibitors and biocides is discussed.