title: The first coordination polymer of lanthanum(III) with a naphthalene-1,4,5,8-tetracarboxylic 1,8-anhydride derivative.
abstract: The title compound, catena-poly[[[heptaaqualanthanum(III)]-mu-1,3-dioxo-2-oxa-1H,3H-phenalene-6,7-dicarboxylato-kappa(2)O(6):O(7)] hemi(4,8-dicarboxynaphthalene-1,5-dicarboxylate) dihydrate], {[La(C(14)H(4)O(7))(H(2)O)(7)](C(14)H(6)O(8))(0.5).2H(2)O}(n), is a dihydrate of a coordination polymer between the dianion of naphthalene-1,4,5,8-tetracarboxylic 1,8-anhydride and the heptahydrated lanthanum(III) ion, charge balanced by an additional 4,8-dicarboxynaphthalene-1,5-dicarboxylate dianion that is located on an inversion centre and is not coordinated to the metal ion. The linear polymeric arrays adopt a comb-like structure, and these pack in pairs with one chain interpenetrating another, like two parts of a zip, to optimize stacking interactions between their ligand fragments. All the components of this compound are further interlinked by an extensive pattern of O-H...O hydrogen bonds throughout the crystal structure. The main scientific significance of the results reported here is that they demonstrate for the first time the feasibility of coordination polymerization of the above organic ligand with lanthanide ions. The resulting polymer has a unique architecture. Finally, the reported structure is a rare example where the tetraacid and the diacid anhydride ligand species co-exist in the same crystal.
authors.affiliation: School of Chemistry, Sackler Faculty of Exact Sciences, Tel-Aviv University, Ramat-Aviv, 69978 Tel-Aviv, Israel.
authors.forename: Rajesh
authors.initials: R
authors.lastname: Koner
authors.forename: Israel
authors.initials: I
authors.lastname: Goldberg