Complexity of imine and amine Schiff-base tin(II) complexes: drastic differences of amino and pyridyl side arms.

A series of homoleptic and heteroleptic imine and amine Schiff-base tin(II) complexes containing dimethylamino and pyridyl side arms were synthesized and structurally characterized. While the tin complexes containing the dimethylamino side arm could be prepared in good yield, unusual cyclodimerization and ligand dimerization were observed for the first time for Schiff-base tin complexes having a pyridyl side arm due to the added stabilization offered by the pyridyl ring. The amine Schiff-base tin(II) complexes were active for the ring-opening copolymerization of succinic anhydride (SA) and cyclohexene oxide (CHO) at 110 °C giving highly alternating poly(SA-alt-CHO).