In situ ligand generation for novel Mn(II) and Ni(II) coordination polymers with disulfide ligand: Solvothermal syntheses, structures and magnetic properties

Two coordination polymers, {[Mn2(L1)2(μ2-H2O)(H2O)4]·5H2O}n 1 and {[Ni(L1)(H2O)2]·2H2O}n 2 (H2L1=2,2′-dithiobisnicotinic acid), were prepared by the solvothermal reactions of the Mn(II) or Ni(II) ions with 2-mercaptonanicotinic acid. In 1, the [Mn2(COO)4] units are connected by the 2,2′-dithiobisnicotinic dianion to form a two-dimensional (4,4)-connected network. In 2, the adjacent Ni(II) ions are connected by the carboxyl groups of the 2,2′-dithiobisnicotinic dianion to form an one-dimensional inorganic rod-shaped chain [Ni(COO)2]n, which are further interconnected by the 2,2′-dithiobisnicotinic ligand, giving rise to a two-dimensional framework. Variable-temperature magnetic susceptibilities of 1 and 2 exhibit overall weak antiferromagnetic coupling between the adjacent metal ions.