Аннотация: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 Na6{[C6H5SiO2)8]2Gd4(μ4-O)} is reported.