Self-assembly of CuCl2, NdCl3, 5-bromosalicylaldehyde and glycylglycine yields the ion-pair copper(II)–neodymium(III) complex, poly[[decaaquabis[μ3-2-({2-[(5-bromo-2-oxidobenzylidene)amino]acetyl}azanidyl)acetato]bis[μ2-2-({2-[(5-bromo-2-oxidobenzylidene)amino]acetyl}azanidyl)acetato]tetracopper(II)dineodymium(III)] bis{[2-({2-[(5-bromo-2-oxidobenzylidene)amino]acetyl}azanidyl)acetato]cuprate(II)} tetradecahydrate], {[Cu4Nd2(C11H8BrN2O4)4(H2O)10][Cu(C11H8BrN2O4)]2·14H2O}n. The anion is planar and mononuclear, showing an approximately square-planar coordination of the metal atom, while the cation is a hexanuclear centrosymmetric transition metal–lanthanide (Cu–Nd) heterometallic complex, with the independent copper cations in square-planar and square-pyramidal coordinations. The asymmetric unit comprises one half of this cation, one anion and seven solvent water molecules. The positions of the six metal centres in the cation reproduce a Chinese knot arrangement. The dipeptidic Schiff base releases three H atoms and can act as a tetradentate, a pentadentate or a hexadentate ligand. Longer interactions between the pentadentate ligands and the Jahn–Teller CuIIcation link the hexanuclear aggregates into cationic chains in the [010] direction in which 14- and 22-membered subloops occur. Extensive hydrogen bonding in three dimensions involves both the coordinated and the solvent water molecules.
1P418 FTIR study of Internal Water Molecules in the Schiff Base Region of Proteorhodopsin(17. Light driven system,Poster Session,Abstract,Meeting Program of EABS &BSJ 2006)
