Syntheses, crystal structures and properties of five divalent transition metal coordination compounds based on a semirigid tetracarboxylic acid ligand

Five divalent transition metal coordination compounds based on a semirigid tetracarboxylic acid have been synthesized by the hydrothermal method, namely, [MnL0.5phen]n (1), [CdL0.5phen]n (2), [Co(H2L)(phen)2H2O]n (3), {[Ni2L(phen)2(H2O)6]·2H2O}n (4) {[Zn2L(phen)4(H2O)2]·2H2O}n (5) (H4L = 1,4-bis(4-oxy-1,2-benzene dicarboxylic acid)benzene, phen = 1,10-phenanthroline). These compounds were structurally characterized by infrared spectra, thermogravimetric analyses and single crystal X-ray diffractions. The isostructural 1 and 2 exhibit the two-dimensional layered structures. Compound 3 and 4–5 reveal a mononuclear and two dinuclear structures, respectively. In addition, the magnetic property of 1 and the photoluminescence of 2 and 5 were also investigated, respectively.