A Series of Rutile Networks Constructed by Dinuclear Transition Metal Units and 5-Carboxyl-1-carboxymethyl-3-oxidopyridimium

A series of three-dimensional coordination polymers [ML(H2O)(2)](n) (M = Mn (1), Co (2), Zn (3), Cd (4); H2L = 5-carboxyl-1-carboxymethyl-3-oxidopyridimium) have been synthesized Under hydrothermal conditions and characterized by single-crystal X-ray diffraction analyses, elemental analyses, IR spectra, and thermogravimetric analyses. Four complexes are isostructural and crystallize in the monoclinic system with space group P2(1)/c. Their structures can be considered constructed from two-dimensional layers, which consist of left- and right-handed helical chains and further linked by L2- ligands into three-dimensional (3D) pillared-layer frameworks. From the topological point of view, the 3D nets are binodal with three- and six-connected nodes and exhibit rutile topology. The experimental magnetic Susceptibilities of 1 and 2 are interpreted with the dimer law, yielding J and g values of 1.02 cm(-1), 1.99 and -0.51 cm(-1), 2.32, respectively. The exchange integrals (J) indicate weak ferromagnetic interactions betweeen two Mn(II) ions in 1 and weak antiferromagnetic interactions between two Co(II) ions in 2, 3 and 4 exhibit intense luminescence in the solid state at room temperature.