Crystal structures and properties of four coordination polymers constructed from flexible pamoic acid

Abstract: Four novel coordination polymers constructed from flexible pamoic acid, namely [Co(pam)(4,4′-bipy)] n ·nH2O (1), [Ni(pam)(4,4′-bipy)(H2O)2] n ·2nCH3CN (2), [Cd(pam)(py)2] n ·npy (3) and [Mn2(pam)2(py)6(H2O)2] n ·2npy (4), (H2pam=pamoic acid, 4,4′-bipy=4,4′-bipyridine, py=pyridine), have been synthesized and characterized by elemental analysis, infrared spectra and X-ray crystallography. Complex 1 is a 2-D coordination polymer constructed from chelating bis-bidentate pam and 4,4′-bipyridine bridging ligands. Complex 2 is a 2-D coordination polymer assembled by bis-monodentate pam and 4,4′-bipyridine, where acetonitrile is filled in the rectangle channels. Both 2-D coordination polymers display undulated (4,4) grid layers as sql topology. Complex 3 displays a 1-D polymeric chain using chelating bis-bidentate pam as bridging ligand. Complex 4 exhibits an interesting bis-monodentate pam-Mn(II) 1-D polymeric chain, in which exist two-type six-coordinated manganese centers. Mn(1) is bound to four pyridine ligands, whereas Mn(2) is combined to two pyridine and two H2O molecules. Their thermal stabilities have been investigated. Cadmium complex 3 displays strong green luminescence with emission maximum at 543nm. [Copyright &y& Elsevier]