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

Six novel 2D metal–quinolone complexes, namely [Cd(cfH)(bpdc)]H2O (1), [M(norfH)(bpdc)]H2O (M=Cd (2) and Mn (3)), [Mn2(cfH)(odpa)(H2O)3]0.5H2O (4), [Co2(norfH)(bpta)(μ2-H2O)(H2O)2]H2O (5) and [Co3(saraH)2(Hbpta)2(H2O)4]9H2O (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.

Graphical abstractSix novel 2D metal–quinolone complexes have been prepared by self-assemblies of the quinolones and metal salts in the presence of long aromatic polycarboxylates .Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights►Compounds 1–3 consist of novel 2D arm-shaped layers based on the 1D {M(COO)}nn+ chains. ► Compounds 4 and 5 are two novel 2D layers based on tetranuclear Mn or Co clusters with kgd topology. ► Compound 6 is the first example of metal–quinolone complexes with 2D bilayer structure. ► Compounds 1–6 represent six unusual examples of 2D metal–quinolone complexes.