Construction of two new Co(II)-organic frameworks based on diverse metal clusters: Highly selective C2H2 and CO2 capture and magnetic properties.

Two new Co(II)-complexes, namely, [(NH 2 Me 2) 2 ][Co 4 (L) 2 (μ 2 -O) 2 (H 2 O) 5 DMF]·2DMF·3H 2 O (1) , [(NH 2 Me 2) 5 ][Co 12 (L) 6 (μ 3 -O) 4 (HCOO)(H 2 O) 6 ]·2DMF·8H 2 O (2) were solvothermally constructed based on a rigid pyridine polycarboxylate ligand (H 4 L, 2,6-di(2′,5′-dicarboxyphenyl) pyridine). Complex 1 and 2 dislay 3D frameworks with various metal cluster. Complex 1 is a 3D porous framework with a (4,8)-connected topology featured by 1D pore structure in a-axis direction with binuclear cluster [Co 2 (COO) 4 O] and tetranuclear cluster [Co 4 (COO) 8 O 2 ]. Complex 2 possess trinuclear cluster [Co 3 (COO) 6 O] and binuclear cluster [Co 2 (COO) 5 O], and it can be clearly observed that 2 is assembled by numbers of nano-cages by twisting a certain angle. Notably, the gas sorption behaviour investigation indicates that the desolvated 1a displays uptake capacity and adsorption selectivity to C 2 H 2 and CO 2 over CH 4. Furthermore, the results of magnetic studies show that complex 2 exhibits antiferromagnetic interactions between Co2+ ions. Two new Co(II)-complexes, namely, [(NH 2 Me 2) 2 ][Co 4 (L) 2 (μ 2 -O) 2 (H 2 O) 5 DMF]·2DMF·3H 2 O (1) , [(NH 2 Me 2) 5 ][Co 12 (L) 6 (μ 3 -O) 4 (HCOO)(H 2 O) 6 ]·2DMF·8H 2 O (2) were solvothermally synthesized based on a rigid pyridine polycarboxylate ligand, 2,6-di(2′,5′-dicarboxyphenyl) pyridine. Dramatically, the gas sorption behaviour investigation manifests that the desolvated 1a displays higher uptake capacities for CO 2 and C 2 H 2 and high selectivity for C 2 H 2 and CO 2 over CH 4. In addition, the results of magnetic property studies show that comple× 2 exhibits antiferromagnetic behavior. [Display omitted] • Two new complexes were constructed based on rigid pyridine polycarboxylate ligand. • Complexes 1 and 2 feature 3D porous frameworks. • The desolvated 1 a displays highly selective capture properties of C 2 H 2 and CO 2. • Complex 2 shows antiferromagnetic behavior. [ABSTRACT FROM AUTHOR]