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 HELICALCOMPLEXES

A new tetradentate ligand (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 i on also has weak interactions with two ClO4- ions, which link the Cu-I I ions in a one dimensional fashion to make an infinite chain. In comp lex 2, Ag(p-bpy)[ClO4], the coordination geometry of Ag-I is flattened tetrahedron. (C) 1997 Elsevier Science Ltd.