Synthesis and structural characterizations of diorganotin(IV) complexes with 2-pyrazinecarboxylic acid

Two types of diorganotin(IV) complexes {[R2Sn(O2CC4H3N2)]2O}2 (R = n-octyl 1, 2-ClC6H4CH23, 2-FC6H4CH25, 4-FC6H4CH27) and R2Sn(O2CC4H3N2)2 (R = n-octyl 2, 2-ClC6H4CH24, 2-FC6H4CH26, 4-FC6H4CH28) were prepared by reactions of diorganotin oxide with 2-pyrazinecarboxylic acid. The complexes 1–8 are characterized by elemental analysis, IR and NMR (1H, 13C, 119Sn) spectroscopies. The complexes {[(n-C8H17)2Sn(O2CC4H3N2)]2O}2 (1) and (n-C8H17)2Sn(O2CC4H3N2)2 (2) are also determined by X-ray single crystal diffraction, which reveal that the endo-cyclic tin atom of complex 1, is seven-coordinate, and the exo-cyclic tin atom is hexa-coordinated geometry, while the complex 2 is seven-coordinated geometry. The nitrogen atom of the aromatic ring participates in the interactions with the Sn atom.