Dongwon Min

One-dimensional copper–pyridinedicarboxylate polymer containing square-planar Cu(II) centers exhibiting antiferromagnetic coupling

Abstract The hydrothermal reaction of Cu(NO 3 ) 2 ·2.5H 2 O with 2,5-pyridinedicarboxylic acid (2,5-PDCH 2 ) led to the formation of aone-dimensional coordination polymer with the empirical formula of Cu(2,5-PDC)(H 2 O) ( 1 ). On the other hand, the hydrothermalreaction of Cu(NO 3 ) 2 ·2.5H 2 O with 2,4-pyridinedicarboxylic acid (2,4-PDCH 2 ) gave a mononuclear Cu(II) compound Cu(2,4-PDC) 2 ( 2 ). The structures of both compounds have been determined by X-ray diffraction. In both compounds, the coordinationsphere of the Cu metal is square-planar. The polymer 1 exhibits strong antiferromagnetic coupling between the paramagneticCu(II) metals in the adjacent layers even in the absence of intervening groups.

Terbium-oxalate-pyridinedicarboxylate coordination polymers suggesting the reductive coupling of carbon dioxide (CO2) to oxalate (C2O42-):[Tb2 (3,5-PDC)2(H2O)4(C2O4)]2H2O and [Tb(2,4-PDC)(H2O)(C2O4)0.5] (PDC=pyridinedicarboxylate)

Abstract Under hydrothermal conditions, Tb(NO3)3·5H2O reacted with 3,5-pyridinedicarboxylic acid (3,5-PDCH2) to give a 3-D coordination polymer with the empirical formula of [Tb2 (3,5-PDC)2(H2O)4(C2O4)]·2H2O (1). Tb(NO3)3·5H2O also reacted with 2,4-pyridinedicarboxylic acid (2,4-PDCH2) to give another 3-D coordination polymer [Tb2 (2,4-PDC)2(H2O)2(C2O4)] (2). The structures of both polymers have been determined by X-ray diffraction. X-ray structure analyses show that both polymers contain bridging oxalate (C2O42−) ligands, which might have been formed by the reductive coupling of CO2 molecules released from the PDC2− ligands through the C–C bond cleavage.

A three-dimensional cobalt(II)-coordination polymer based on 3,5-pyridinedicarboxylate

Abstract Hydrothermal reaction between cobalt(II) nitrate and 3,5-pyridinedicarboxylic acid in the presence of NaOAc and NaCl gave a 3-D cobalt(II)-coordination polymer, Co(3,5-pyridinedicarboxylato)(H 2 O) ( 1 ). X-ray structure determination showed that compound 1 has a 3-D infinite network based on cobalt–carboxylate building blocks.

Two-dimensional cobalt-bipyridinedicarboxylate coordination polymer: [Co(2,2 ′ -bipyridine-5, 5 ′ -dicarboxylato) (H 2 O)]·(H 2 O)

Abstract Hydrothermal reaction between cobalt(II) nitrate and 2,2′-bipyridine-5,5′-dicarboxylic acid in the presence of NaOAc gave a two-dimensional coordination-polymer of cobalt(II), [Co(2,2′-bipyridine-5,5′-dicarboxylato)(H2O)]·(H2O) (1). X-ray structure determination showed that compound 1 has a two-dimensional infinite network based on cobalt-bipyridinedicarboxylate building blocks and has a relatively small channel of 5.0×6.6 A.