A series of 2D metal–quinolone complexes: Syntheses, structures, and physical properties

Six novel 2D metal–quinolone complexes, namely [Cd(cfH)(bpdc)]radical dotH2O (1), [M(norfH)(bpdc)]radical dotH2O (M=Cd (2) and Mn (3)), [Mn2(cfH)(odpa)(H2O)3]radical dot0.5H2O (4), [Co2(norfH)(bpta)(μ2-H2O)(H2O)2]radical dotH2O (5) and [Co3(saraH)2(Hbpta)2(H2O)4]radical dot9H2O (6) (cfH=ciprofloxacin, norfH=norfloxacin, saraH=sarafloxacin, bpdc=4,4′-biphenyldicarboxylate, odpa=4,4′-oxydiphthalate, bpta=3,3′,4,4′-biphenyltetracarboxylate) have been synthesized and characterized. Compounds 1–3 consist of 2D arm-shaped layers based on the 1D {M(COO)}nn+ chains. Compounds 4 and 5 display 2D structures based on tetranuclear manganese or cobalt clusters with (3,6)-connected kgd topology. Compound 6 exhibits a 2D bilayer structure, which represents the first example of metal–quinolone complexes with 2D bilayer structure. By inspection of the structures of 1–6, it is believed that the long aromatic polycarboxylate ligands are important for the formation of 2D metal–quinolone complexes. The magnetic properties of compounds 3–6 was studied, indicating the existence of antiferromagnetic interactions. Furthermore, the luminescent properties of compounds 1–2 are discussed.