Synthesis of carbido and related derivatives from calcium carbide and ruthenium carbonyl clusters

Abstract

Reactions between a carbide anion (C₂²⁻) source and ruthenium cluster carbonyls are reported for the first time. The reaction between CaC₂ and Ru₃(CO)₁₂, carried out in thf, affords putative Ca[Ru₁₀(C)₂(CO)₂₄], which can be converted into [ppn]₂[Ru₁₀(C)₂(CO)₂₄]( 1) in overall 60% yield. The X-ray structure of 1 as its 2CH₂C1₂ solvate is described, together with those of the minor products Ru₄(µ₄-HC₂H)₂(µ-CO)₂(CO)₉( 3), Ru₆C(µ₃-HC₂Me)(CO)₁₅( 4) and Ru₄(µ₄-CHCHCO)(µ-CO)(CO)₁₀(tmeda)( 5). The latter contains an Ru-spiked Ru₃ core carrying a CHCHCO ligand; the tmeda chelates the spike Ru atom. The only product from Ru₃(µ-dppm)(CO)₁₀ and CaC₂ is the known compound Ru₆(µ₄-CCH₂)₂(µ-dppm)₂(CO)₁₂( 6), formed in 24% yield.