Cyclooligosiloxanolate cluster complexes of transition metals and lanthanides

Cyclooligosiloxanolate complexes of higher valent transition metals and lanthanides were synthesized and characterized by single-crystal X-ray diffraction experiments, spectra, cyclic voltammetry, conductivity and magnetic behaviour. These complexes are sandwich-type clusters containing assemblies of 4 to 8 metals between siloxanolate ligand 'layers'. A high degree of electron delocalization in the metal containing fragment of these complexes is detected by electrochemical and magnetic measurements, The synthesis, crystal and molecular structure determined by X-ray diffraction of Na-6{[C6H5SiO2)(8)]Gd-2(4)(mu(4)-O)} is reported.