Syntheses and crystal structures of dimethyltin (IV) derivatives with 2,6-pyridinedicarboxylic acid

A novel cyclic dimethyltin complex [Me2Sn(2,6-pdc)]3 (1) (2,6-pdc = 2,6-pyridinedicarboxylate) was synthesized by the reaction of dimethyltin (IV) dichloride and 2,6-pyridinedicarboxylate acid in methanol under solvothermal conditions (150 °C). However, under room temperature (25 °C), we obtained a ladder complex [Me2Sn(2,6-pdc)]2(MeOH)2 (2). Characterization of complexes 1 and 2 was achieved using elemental analysis, IR, 1H, 13C and 119Sn NMR spectra and X-ray diffraction. X-ray data of 1 revealed that it was an unusual cyclic complex with a discrete cyclotrinuclear unit, in which the 12-membered cyclic cavity is almost completely planar. X-ray data of 2 showed that it was a ladder complex, in which a crystallizing methanol molecule is found in each formula unit.