Rational assembly of Pb(II)/Cd(II)/Mn(II) coordination polymers based on flexible V-shaped dicarboxylate ligand: Syntheses, helical structures and properties

Six new coordination polymers, namely, [Pb(L)(H2O)] (1), [Pb(L)(Phen)] (2), [Pb-2(L)(2)(4,4'-bipy)(0.5)] (3), [Cd (L)(phen)1 (4), [Cd(L)(4,4'-bipy)]center dot H2O (5) and [Mn(L)(4,4'-bipy)center dot H2O (6) have been synthesized by the hydrothermal reaction of 2,2'-[hexafluoroisopropylidenebis(p-phenyleneoxy)]diacetic acid (H2L) with Pb(II)/Cd(II)/Mn(II) in the presence of ancillary ligands 4,4'-bipyridine (4,4'-bipy) or 1,10-phenanthroline (phen). Complexes 1 and 4-6 exhibit 2-D structures, and complexes 2-3 display 3-D frameworks, of which L2- ligands join metal ions to single-stranded helical chains of 1, 3-6 and double-stranded helical chains of 2. Complexes 2 and 3 also contain double-stranded Metal-O helices. Topology analysis reveals that complexes 1 and 4 both represent 4-connected sql net, 2 represents 6-connected pcu net, 3 exhibits a novel (3,12)-connected net, while 5 and 6 display (3,5)-connected gek1 net. The six complexes exhibit two kinds of inorganic-organic connectivities: 1(0)O(2) for 1, 4-6, and 1(1)O(2) for 2-3. The photoluminescent properties of 4-5 and the magnetic properties of 6 have been investigated. (C) 2014 Elsevier Inc. All rights reserved.