Metal-induced different structures and properties of two coordination polymers based on a semi-flexible carboxylic ligand

Abstract

Pictogram: Two 3D coordination polymers (Cu/Ni-based) have been solvothermal synthesized and characterized. In addition, their magnetic properties, electrochemical properties and gas adsorption properties were also studied. • Two 3D coordination polymers (Cu/Ni-based) have been solvothermally synthesized and characterized. • The magnetic research showed that there are antiferromagnetic and ferromagnetic interactions between adjacent metal ions of 1 and 2, respectively. • In addition, CP 1 showed good electrochemical and gas adsorption properties. Two coordination polymers (CPs), namely, {[Cu 2 L(H 2 O) 3.5 ]·1.5H 2 O} n ( 1 ) and {[Ni 2 L(H 2 O) 5 ]·H 2 O} n ( 2 ) have been synthesized from the ligand of 3, 3′, 5, 5′-diphenyl ether tetracarboxylic acid(C 16 H 10 O 9 , H 4 L) and metal salts. CPs 1 and 2 were characterized by single crystal X-ray diffraction, infrared (IR) spectra, elemental analysis, powder X-ray diffraction (PXRD), and thermogravimetric (TG) analysis. Structure analysis indicates that both the compounds are composed of binuclear clusters linked by L 4- ligands, forming 3D framework with {4. 6 4 . 8} 2 {4 2 . 6 2 . 8 2 } and {6 6 } topology, respectively. The temperature dependence of the magnetic susceptibility of 1 reveals antiferromagnetic exchange between adjacent Cu(II) ions. In contrast, the magnetic behavior of 2 indicates that there is mainly strong ferromagnetic coupling between the two Ni(II) ions. In addition, due to the open metal site of Cu(II) ion in 1 , it showed good electrochemical performance. Furthermore, the adsorption properties of N 2 , CO 2 and CH 4 for 1 were studied. The results showed that the average heat of CO 2 adsorption is 11.41 kJ·mol −1 and the average selectivity coefficient of CO 2 /CH 4 (1:9, v/v) is 32.85 under 298 K and 1 bar.