Two New Co(II) Complexes Based on Dicarboxylate Linker and N-Donors Ligands: Syntheses and Crystal Structures

The use of both 4-bromoisophthalic acid (H2Brip)/5-nitroisophthalic acid (H2nip) and 4,4-dipyridyldisulfide (dpds) with Co(II) ion under hydrothermal conditions has provided two new Co(II) coordination polymers, [Co(dps)(Brip)]n (1) and [Co(H2O)(dpds)(nip)]n (2), respectively. The two compounds have been characterized by elemental analysis, FT-IR spectroscopy, and X-ray single-crystal diffraction. The starting reagent dpds ligand was converted to dps (4,4-dipyridylsulfide) in 1. For complex 1, it crystallized in monoclinic system, P21/c space group. Two Co ions are linked by carboxylate oxygen atoms to form a 4-membered [Co2O2] ring. The rings are linked by Brip to generate a 1D polymeric motif. These 1D motifs are further connected through dps to generate a 2D network. For complex 2, it crystallized in orthorhombic system, Pbcn space group. The adjacent Co(II) ions are bridged by Brip to form an alternate 1D chain. Such 1D chains are further connected by dpds to generate a 3D twofold interpenetrating diamondoid network.