Reactivity of an Octanuclear Copper(I) Siloxide Compound - Isolation of a Copper(II) Oxo Compound with a Supertetrahedral Core

The reactivity of the octanuclear copper(I) siloxide compound [L4Cu8], (1) (L2– = –OPh2SiOSiPh2O–), towards external substrates was tested. In the presence of N‐donor molecules like acetonitrile and propionitrile 1 decomposes with formation of cyclic siloxane rings. Contact with 2,2′‐bipyridine (bipy) leads to the formation of a mixed valent tricopper complex [L2Cu3(bipy)2], (3), which likely represents an intermediate of the disproportion of 1 to elemental copper and a mononuclear copper(II) complex [LCu1(bipy)], (2), which was isolated and characterized as the final product. The addition of O2 to 1 leads to an unprecedented supertetrahedral copper(II) complex [L6Cu10(μ4‐O)4(MeCN)4], (4), that incorporates four μ4‐oxido ligands. The structural parameters for compounds 2–4 were elucidated by single‐crystal X‐ray crystallography.