Kamal Kumar Bisht - Synthesis, characterization and X-ray crystallographic investigation of 2-D hybrid hydrogen bonded and rectangular grid networks in Cu(II) and Co(II) metal complexes

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      Publication Details (including relevant citation   information):

        Volume 29, Issue 7, 10 May 2010, Pages 1801-1809



      Two copper/cobalt metal complexes, [Cu(l-cys)(2,2′-bpy)(H2O)]   (1) and {[Co(l-cys)(4,4′-bpy)(H2O)]·H2O}n  (2), with the N-donor ligands   2,2′-bipyridyl/4,4′-bipyridyl and the l-cysteate dianion (l-cys) have been synthesized by different   reaction methods and structurally characterized. Compound   1 exists as a discrete monomeric unit in which   the metal ions possess a distorted square-pyramidal coordination   environment provided by nitrogen atoms from the 2,2′-bpy ligand   and the amino-carboxylate group of l-cys in a chelated coordination, constituting   the square base, and with a water molecule occupying the axial   coordination site to complete the penta coordination. Packing and   hydrogen bonding interactions of 1 reveal that   the screw related monomeric units are involved in intermolecular   hydrogen bonding with the formation of helical bilayers via   O–Hcdots, three dots, centeredO and N–Hcdots, three dots, centeredO interactions. These hydrogen   bonded bilayered helical nets are involved in stacking and   C–Hcdots, three dots, centeredO interactions which generate a two   dimensional hydrogen bonded network in the bc-plane.   Complex 2 is a two dimensional coordination   polymer which is insoluble in common polar and non-polar   solvents. The coordination around the metal center possesses a   distorted octahedral geometry. The adjacent metal centers are   bridged via the carboxylate group of the l-cys moiety in a syn–anti fashion,   generating a one dimensional helical network along the   b-axis. Adjacent helical chains are further pillared by   the 4,4′-bpy ligand through the terminal nitrogen atoms,   generating a two dimensional square grid type coordination   network. Both the complexes are characterized well by various   physico-chemical techniques such as CHN analysis, IR   spectroscopy, PXRD and CD analysis.

      Address (URL): http://www.sciencedirect.com/science/article/pii/S0277538710001300