Four coordination polymers constructed from a multicarboxylate ligand and metal centers various from Ba2+, Cu2+, Zn2+ to Gd3+: Syntheses, crystal structures and properties

Hydrothermal reactions between H(4)ODPA (2,2',3,3'-oxydiphthalic acid) and metal ion salts of Ba2+, Cu2+, Zn2+ and Gd3+ afford four novel coordination polymers [Ba(H(2)ODPA)(H2O)(4)] center dot H2O (1), [Cu-2(ODPA) (H2O)(3)] center dot H2O (2), Zn-2(ODPA)(H2O)(2) (3) and [Gd(HODPA)(H2O)(3.5)] center dot H2O (4), accordingly. These polymers show great differences in regard to their structures and properties originated from the variation of size and coordination geometry of the metal ions. Compound 1 presents puckered achiral layer structure with (4.82) topology with helices, 2 has a 63 topology with copper tetramer as SBUs, 3 has chiral layer with two kinds of helices built up from Zn-binuclear paddle-wheel like SBUs, and 4 features a simple 1D helix with opposite chirality. Compound 3 shows obvious fluorescent emissions upon excitation. Compound 2 shows ferromagnetic interactions between Cu-II centers bridged by carboxylate groups, whereas compound 4 presents weak ferromagnetic interaction between Gd-III ions. (C) 2008 Elsevier B.V. All rights reserved.