Crystal structure, magnetic properties and multiplex photoluminescence of Dy-exclusive coordination polymer based on quinoline-2-carboxylic acid

Abstract

An example of Dy-exclusive 3D coordination polymer [Dy2(L)4Cl2(H2O)4]n (1), was obtained by reacting quinoline-2-carboxylic acid (HL) with DyCl3·6H2O in methanol at 80 °C. Although there are two types of Dy(III) in one independent unit of 1 taking eight coordination positions, they are respectively in different coordination environments. One of Dy(III) is in an O8 coordination environment formed by four O provided by ligand L and four coordinated H2O molecules. The other Dy(III) is in the N2O4Cl2 coordination environment formed by the N2O4 provided by the ligand L and the chloride ion coordinated as terminal groups. The six ligands in a single unit have four different coordination modes. Magnetic studies have shown that 1 exhibits field-induced single-molecule magnets behavior. Photoluminescence test results of the ligand HL and the polymer showed that 1 showed a characteristic band of the lanthanide metal ion in addition to the luminescence behavior of the ligand HL.