Bridging methylene and π-allylic bonding modes in tetranuclear osmium clusters; the X-ray crystal structures of [Os₄H₂(CO)₁₂CHCH₂Ph] and [Os₄H₂(CO)₁₁MeCCPhCHPh]

Abstract

[Os4H3(CO)11CH:CHR] reacts with CO under pressure to give edge bridging methylenic compounds [Os4H2(CO)12CHCH2R] and, when R = H, with acetylenes, R′C2R″, to give π-allylic derivatives of the form [Os4H2(CO)11MeCCR′CHR″]; the structures of these two compounds have been confirmed by X-ray diffraction analyses.