Synthesis and crystal structures of manganese(II) complexes with the ligands from in situ oxidation of 2-mercaptonanicotinic acid

Three manganese(II) complexes, [Mn(L2)(phen)(H2O)]n · nH2O (1), [Mn(L2)(2,2′-bipy)(H2O)]n · 2nH2O (2) and [Mn(4,4′-bipy)2(H2O)2]n · 2nL3 (3) (phen = 1,10-phenanthroline, 2,2′-bipy = 2,2′-bipyridine, 4,4′-bipy = 4,4′-bipyridine, L2 = 2-sulfonato-nicotinate and L3 = 2-(3-carboxy-pyridine-2-yl disulfanyl)-nicotinic acid anion), have been prepared from in situ metal/ligand solution reactions. By in situ oxidation of 2-mercaptonanicotinic acid (L1) with the existence of different co-ligands, the unexpected oxidative formation of the disulfide bond and S–O bond are observed.