Control formation of rigid linear and flexible zig-zig complexes based on Zn(II) and hydroxyquinoline carboxylate ligand system

Two novel zinc complexes, [Zn(H-hqc)2(bpy)(H2O)2] (1) and [Zn(H-hqc)2(bpe)]∙H2O (2), where H2-hqc = 2-hydroxyquinoline-4-carboxylic acid, bpy = 4,4′-bipyridine and bpe = 1,2-bi(4-pyridyl)ethylene, have been prepared under hydrothermal condition. Complex 1 displays a 1D rigid linear chain structure while complex 2 displays 1D flexible zig-zag chain structure. Coordination number of the central Zn ion in complex 1 is six and in complex 2 is four. The structural differences of these complexes suggest the effect of size of the bridging ligands on the construction of metal organic frameworks with the same metal ion under solvothermal conditions.

Graphical abstractPresented here are the two novel zinc complexes exhibiting auxiliary ligands controlled structural diversity.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Two zinc complexes based on 2-hydroxyquinoline-4-carboxylic acid were obtained. ► The complexes were structurally characterized by single-crystal X-ray diffraction. ► The complexes exhibited auxiliary ligands controlled structural diversity.