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), [Pb2(L)2(4,4′-bipy)0.5] (3), [Cd(L)(phen)] (4), [Cd(L)(4,4′-bipy)]·H2O (5) and [Mn(L)(4,4′-bipy)]·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: I0O2 for 1, 4–6, and I1O2 for 2–3. The photoluminescent properties of 4–5 and the magnetic properties of 6 have been investigated. Six new Pb(II)/Cd(II)/Mn(II) coordination polymers with helical structures based on flexible V-shaped dicarboxylate ligand have been synthesized and structurally characterized. Photoluminescent and magnetic properties have been investigated. [Display omitted] •Six novel M(II) coordination polymers with 2,2′-[hexafluoroisopropylidenebis(p-phenyleneoxy)]diacetic acid and N-donor ligands.•Complexes 1–6 show diverse intriguing helical characters.•The luminescent properties of complexes 1–5 were investigated.•Complex 6 shows antiferromagnetic coupling.