Synthesis, structure, and luminescence properties of arylpyridine-substituted terpyridine Zn(II) and Cd(II) complexes

Two terpyridine derivatives, 4'-(4-(pyridin-4-yl)phenyl)-[2,2':6',2 '']terpyridine (L1) and 4'-(4'-(pyridin-4-yl)-[1,1'-biphenyl]-4-yl)-[2,2':6',2 '']terpyridine (L2) have been synthesized by palladium-catalyzed cross-coupling reactions, and their metal complexes [Zn(L1)(2)](ClO4)(2)center dot 2MeOH center dot CHCl3 (1) and [Cd(L2)(2)] (ClO4)(2)center dot DMF.2.8H(2)O (2) characterized by single crystal X-ray crystallography and spectroscopic methods including electronic absorption and emission measurements. In the crystalline materials, both metal ions have the expected pseudo-octahedral N-6 coordination environment and the lattice structures appear to be influenced by aromatic aromatic interactions involving the heteroaryl tails and the pyridyl rings of the terpyridine units. In solution and in the solid state, the complexes display blue emission attributed to an intramolecular charge transfer transition. (C) 2012 Elsevier Ltd. All rights reserved.