An octanuclear 3-phenyl-5-(2-pyridyl)pyrazolate/phenylsilsesquioxane complex: synthesis, unique structure, and catalytic activity.

The first metallasilsesquioxane bearing pyrazolylpyridine ligands, the Cu8-based complex 1, adopts a cage-like structure with two zigzag-type copper tetramers sandwiched by two cyclic Si5 silsesquioxane ligands. The four 3-phenyl-5-(2-pyridyl)pyrazolate ligands in 1 exhibit dual (chelating and bridging) modes of ligation. Compound 1 is very active in the oxidation of alkanes and alcohols.