BIMETALLIC CYCLOOLIGOSILOXANOLATE COMPLEXES OF COPPER AND NICKEL

The bimetallic cyclosiloxanolate cluster complexes Na[(PhSiO2)(6)Cu4Ni 2( mu(6)-Cl)(PhSiO2)(6)] (1) and Na[ (PhSiO2)(6)Cu3Ni3(mu(6)-Cl)(PhSiO 2)(6)] (2) were prepared by Na+ and Ni2+ ion exchange from in situ gen erated Na-2{[(PhSiO2)(6)](2)Na4Ni4(OH)(2)}. Complexes 1 and 2 were cha racterized by analytical, spectroscopic and electrochemical methods as well as complex 2 by single-crystal X-ray diffraction. The X-ray stru cture shows a sandwich-type array comprising two superimposed cyclosil oxanolate rings and an M6Cl unit in between. For the first time the re gioselectivity of the metal ion exchange could be deduced from the X-r ay structural parameters. (C) 1998 Elsevier Science S.A. ALI rights re served.