Synthesis and crystal structure of a cobalt(II) coordination polymer constructed from 2,6-pyridinedicarboxylate anion and 1,3-bis(4-pyridyl)propane nitrogen ligand

The coordination polymer named {[Co(H2O)4(BPP)][Co(dipic)2]·H2O}n (dipic = 2,6-pyridinedicarboxylate and BPP = 1,3-bis(4-pyridyl)propane) has been synthesized by the diffusion method and characterized by thermal analysis, vibrational spectroscopy and single crystal X-ray diffraction analysis. The compound is formed by an one-dimensional polymeric cationic chain, in which the BPP ligands connect the Co2 sites, and an anionic moiety formed by Co1 center and two dipic2− anions. Both crystallographic independent metal sites adopt a distorted octahedral geometry. Co2 center is coordinated by two nitrogen atoms from BPP ligands and four oxygen atoms from aqua ligands, while Co1 center is coordinated by two nitrogen atoms and four oxygen atoms from two dipic2− anions. The cationic and anionic moieties are connected through hydrogen bonding interactions leading to a 3D supramolecular array.