X-ray crystal structure of copper(II) and silver(I) complexes with the new ligand 1,4-bis(5'-methyl-2,2'-bipyridine-5-ethyl)-benzene: The effects of substituent and linking position on the assembly of helical complexes

A new tetradentate ligand 1,4-bis(5'-methyl-2,2'-bipyridine-5-ethyl)-benzene(p-bpy) and its Cu-II and Ag-I complexes were synthesized. In complex 1, Cu(p-bpy)[ClO4](2) . 0.5MeCN, the four nitrogen atoms of the ligand coordinate with one Cu-II to form a flattened tetrahedron. The metal ion also has weak interactions with two ClO4- ions, which link the Cu-II ions in a one dimensional fashion to make an infinite chain. In complex 2, Ag(p-bpy)[ClO4], the coordination geometry of Ag-I is flattened tetrahedron. (C) 1997 Elsevier Science Ltd.