Synthesis and characterization of coordination polymers of a carboxylato cyclophane with metal [Zn(II) and Cd(II)]-2,2′-bipyridines
摘要:
N,N',N '',N'''-Tetrakis(3-carboxy-propionyl)-1,6,20,25-tetraaza-[6.1.6.1] paracyclophane, H(4)cp has beencomplexed with metal (Zn(II) and Cd(II)) 2,2'-bipyridyls. The resulting complexes of the composition [{Zn(2.2'-bPY)}(2)(cP)](n)center dot 4H(2)O 1 and [{Cd(2,2'-bpy)}(2)(cp)](n)center dot 5H(2)O 2 (2.2'-bPY = 2,2'-bipyridine) have been characterized using spectroscopic (IR, solid state UV-Vis), elemental analysis and single-crystal X-ray diffraction measurements. In these complexes the cyclophane coordinates in different modes, and in complex 2, Cd(II) is hepta-coordinated. However, under harsh reaction conditions (using excess nitric acid and a longer reaction time) debranching of the cyclophane is observed in the reaction of Zn(2,2'-bpy)(NO3)(2) with H(4)cp, and a complex of the composition [Zn(2,2'-bpy)(Suc)](n) 3 (suc = succinate) is isolated. Using non-covalent interactions, complexes 1 and 2 provide 3D supramolecular structures, whereas an infinite 1D chain structure is observed for complex 3. The thermal and photoluminescence properties of the complexes have also been studied. (C) 2010 Elsevier Ltd. All rights reserved.