Six new coordination polymers based on a tritopic pyridyldicarboxylate ligand: structural, magnetic and sorption properties

Using a rigid ligand, pyridine-3,5-bis(phenyl-4-carboxylic) acid ( H2L ), six new coordination polymers have been synthesized under solvothermal conditions, formulated as [Co( L )(DMF)] ( 1 ), [Co( L )(H 2 O)]·DMF ( 2 ), [Co 3 ( L ) 2 (HCOO) 2 (H 2 O) 2 ] ( 3 ), [Co 5 ( L ) 4 (OH) 2 (H 2 O) 2 ]·0.5DMF·H 2 O ( 4 ), [Mn( L )(H 2 O)]·DMF ( 5 ), and [Zn( L )]·DMF ( 6 ) (DMF = N , N -dimethylformamide). Complex 1 exhibits a 2D layer structure with a four-connected net. 2 is also a 2D layer net which forms a 2D stacked layers porous framework through hydrogen bonding interactions. In 3 , 10-connected clusters [Co 3 (COO) 6 ] are extended by a L 2− linker to construct a 3D (3,10)-connected framework with a (4·6·8)(4 2 ·6 2 ·8 10 ·10) topology net. As for 4 , a rare pentanuclear cluster, [Co 5 (μ 3 -OH) 2 (COO) 8 N 4 ], serves as a 12-connected node to give a 3D (3,12)-connected framework with a larger solvent accessible volume. 5 shows a 2D 4 4 layer framework by considering Mn( ii ) as a four-connected node. 6 exhibits a 3D framework based on 1D Zn–(COO)–Zn chains. All complexes have been characterized by single-crystal X-ray diffraction, IR spectroscopy, elemental analysis, thermogravimetric analysis and powder X-ray diffraction measurements. The magnetic properties of complexes 1–5 and the photoluminescence properties for 6 have been investigated. H 2 , N 2 and CO 2 adsorption measurements were carried out for 4 .