A 3D interpenetrated Co(II)-glutarate coordination polymer: Synthesis, crystal structure, magnetic and adsorption properties

A 3D entangled coordination polymer {[Co-4(glu)(4)(bpp)(2)]}(n) 1 was synthesized from a solvothermal reaction between Co(II), glutaric acid (H(2)glu) and 1,3-bis(4-pyridyl)propane (bpp). The crystal structure was determined by single crystal X-ray diffraction and the topological description indicates a 3D -> 3D interpenetration in the pcu-coordination polymer, pillared by bpp ligands. Crystal structure presents four crystallographically distinct Co(II) metal centers conferring different coordination environments: tetrahedral, octahedral and trigonal bi-pyramidal. Spectroscopic (FTIR and Raman), thermal analysis and magnetic studies were employed to chemical characterization. SQUID magnetometry analysis indicated weak overall antiferromagnetic interactions between the Co(II) ions. High-Field Electron Paramagnetic Resonance (HFEPR) spectra suggest that the Co(II) ions in compound 1 are high-spin (S = 3/2). The material showed good thermal stability decomposing above 300 degrees C. CO2 adsorption studies carried out in the pressure range of 0 to 40 bar at room temperature revealed a favorable solid-gas interaction at low pressure. The amount of CO2 adsorbed on compound 1 continuously increased as the pressure increased and no gas saturation is observed suggesting a multilayer phenomenon of CO2 uptake. Powder X-ray diffraction analysis of compound 1 after CO2 measurements at 40 bar revealed no structural change.