Reversible Os–Os bond breaking in the high nuclearity carbido-dianion [Os10C(CO)24]2– on reaction with halogens; X-ray structure analysis of [(Ph3P)2N][Os10C(CO)24I] and Os10C(CO)24I2

Abstract

The carbido-dianion [Os₁₀C(CO)₂₄]^2– reacts with halogens (X₂) to give first [Os₁₀C(CO)₂₄X]^– and then Os₁₀C(CO)₂₄X₂(X = CL,Br,I) and these clusters regenerate the dianion on treatment with nucleophilic reagents such as X^–, PR₃ or C₅H₅N; X-ray analysis of [(Ph₃P)₂N]-[Os₁₀C(CO)₂₄I] and Os₁₀C(CO)₂₄I₂ shows that the reactions break Os–Os bonds on the metal surface giving ‘butterfly’ indentations bridged by I atoms.