Mn^II/Co^II‐Terephthalate Frameworks Containing Dipyridine Coligands: Syntheses, Crystal Structures, Magnetic Behaviors, and Thermal Studies

Abstract

Abstract Three new metal–organic hybrid polymeric networks of Co II and Mn II with the molecular formulae [Co(bpp)(tp)(H 2 O) 2 ] ( 1 ), [Mn(bpds)(tp)(H 2 O) 2 ] · (bpds) ( 2 ), and [Mn(4,4′‐bipy)(H 2 O) 4 ] · (tp) ( 3 ) (bpp = 4,4′‐trimethylenedipyridine; bpds = 4,4′‐bipyridyl disulfide; 4,4′‐bipy = 4,4′‐dipyridyl; tp = terephthalate) have been synthesized and characterized by single‐crystal X‐ray diffraction studies, low temperature (300–2 K) magnetic measurements, and thermal behaviors. The structure determination of complexes 1 and 2 reveals a parallel interpenetrated structure of 2D layers with (4,4) topology, with metal ions at the nodes connected through tp and N , N ‐donor coligands. The octahedral N 2 O 4 chromophore surrounding the metal ion results from trans located tp oxygens, two water molecules, and two nitrogen donors of the co‐ligands in the cis position. The presence of uncoordinated bpds between the interpenetrated layers leads to the formation of a wafer‐like structure for 2 . In complex 3 , however, manganese( II ) ions bridged by 4,4′‐bipy and coordinated by four water molecules give rise to a 1D polymeric chain. The adjoining chains encapsulate terephthalate anions (tp) to give a 3D structure through H‐bonding. Low‐temperature magnetic data indicate weak antiferromagnetic coupling in complexes 1 and 2 . (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)