Zinc(II) complexes of amide- and urea-substituted 8-hydroxyquinolines

A series of amide- and urea-substituted 8-hydroxyquinoline ligands 1–6-H are used for the formation of zinc(II) complexes. Hereby in general 2:1 complexes are obtained and the X-ray structure of [(3)2Zn] reveals the presence of a coordination polymer in the solid state. Only the derivatives of 7-amino-8-hydroxyquinoline 4-H and 5-H form trinuclear hexa-helical 6:3 complexes which exhibit interesting structural and NMR and fluorescence spectroscopic properties.