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

Abstract Six new coordination polymers, namely, [Pb( L )(H 2 O)] ( 1 ), [Pb( L )(phen)] ( 2 ), [Pb 2 ( L ) 2 (4,4′-bipy) 0.5 ] ( 3 ), [Cd( L )(phen)] ( 4 ), [Cd( L )(4,4′-bipy)]·H 2 O ( 5 ) and [Mn( L )(4,4′-bipy)]·H 2 O ( 6 ) have been synthesized by the hydrothermal reaction of 2,2′-[hexafluoroisopropylidenebis( p -phenyleneoxy)]diacetic acid (H 2 L ) 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 L 2− 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: I 0 O 2 for 1 , 4 – 6 , and I 1 O 2 for 2 – 3 . The photoluminescent properties of 4 – 5 and the magnetic properties of 6 have been investigated.