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Three complexes with the ditopic ligand 4′-[4-(quinolin-8-yloxymethyl)phenyl]-2,2′:6′,2′′-terpyridine (abbreviated as L), [Ni(L)2](CH3COO)2 ( 1), [Cd(L)2](ClO4)2 ( 2), and [Cu2(L)2](ClO4)4 ·4DMF ( 3), were synthesized and characterized by elemental analysis, IR spectroscopy, and structurally analyzed by X-ray single-crystal diffraction. Interestingly, in complexes 1 and 2, two ligands adopt a tridentate chelating pattern where the oxaquinoline group is non-coordinated and coordinate with one MII ion ( M = Ni for 1, M = Cd for 2) to form a mononuclear unit. In complex 3, two ligands bridge two CuII ions by pyridyl N atoms, ethereal O atoms, and quinolyl N atoms in a head-to-tail mode to generate a dinuclear [Cu2L2] unit. Moreover, extended 1D and 2D supramolecular architectures are further constructed in 1- 3 by multiple secondary interactions such as aromatic stacking and hydrogen bonding. Notably, the structural diversity of complexes 1- 3 can be properly assigned to the central metal ions that have distinct coordination preferences. In addition, luminescent properties of the ligand and complex 2 were also investigated. [ABSTRACT FROM AUTHOR]

By using a flexible multicarboxylate ligand, 2,2′-(2-((2-carboxy-5-methylphenoxy)methyl)-2-(4-methylphenylsulfonamido)propane-1,3-diyl)bis(oxy)bis(4-methylbenzoic acid) (H 3 L), and two kinds of N-donor ligands, four new zinc(II) and cadmium (II) metal coordination complexes [Zn 2 (HL 2− ) 2 (phen) 2 ]·2H 2 O ( 1 ), [Zn(HL 2− )(4,4′-bpy) 0.5 (H 2 O)] n ( 2 ), [Cd(HL 2− )(phen)(H 2 O)] n ( 3 ), and [Cd 2 (HL 2− ) 2 (4,4′-bpy) 3 ] n ·n(DMF·CH 3 OH·H 2 O) ( 4 ) (phen = 1,10-phenanthroline, and 4,4′-bpy = 4,4′-dipyridine) have been prepared under solvothermal conditions and structurally characterized by elemental analysis, FT-IR spectra, thermogravimetric analysis. The various topologies of the structures have been generated by adjusting the auxiliary N-donor ligand and the central metal ions. Complex 1 features a discrete neutral dinuclear cage structure, complex 2 displays a 1D ladder-like chain, complex 3 exhibits a 1D infinite zigzag chain, while complex 4 possesses a rare 5-connected 2D networks with the point symbol (4 8 ·6 2 ). These results indicate that both the metal center and the auxiliary N-donor ligand have significant influences on the structure of the final assembly. Moreover, the thermal stabilities and luminescent properties of 1 – 4 have also been investigated in detail. [ABSTRACT FROM AUTHOR]

A simple quinoline-based fluorescent probe L for Ag + has been developed. Probe L shows fluorescence enhancement (turn on) response towards Ag + with high selectivity in aqueous media (methanol–water, v/v = 3:7, pH 7.2, 20 mM Tris–HCl) based on a combinational effect of the inhibition of intermolecular photoinduced proton transfer and chelation-enhanced fluorescence. And an obvious fluorescent color change could be observed by naked eyes under the light of 365 nm. The binding mode between L and Ag + has been found to be 1:1 based on the fluorescence/absorption titration, ESI-MS and further confirmed by X-ray crystallography. [ABSTRACT FROM AUTHOR]