The reaction of Ru3(CO)12 with 1,4-dichloro-but-2-yne in basic methanolic solution. Synthesis and crystal structure of (μ-H)2Ru3(CO)9{μ3-η2-[H2Cdouble bond; length as m-dashC(H)Ctriple bond; length of mdashCC(double bond; length as m-dashO)OCH3]}

The title complex is obtained by reacting Ru3(CO)12 with 1,4-dichloro-but-2-yne (ClCH2Ctriple bond; length of mdashCCH2Cl, DCB) in CH3OH/KOH solution (followed by acidification with HCl). The X-ray structure analysis shows that (μ-H)2Ru3(CO)9{μ3-η2-[H2Cdouble bond; length as m-dashC(H)CCC(double bond; length as m-dashO)OCH3]} complex contains a “parallel” ene-yne acetyl substituent, H2Cdouble bond; length as m-dashC(H)Ctriple bond; length of mdashCC(double bond; length as m-dashO)OCH3; the formation of such a ligand starting from DCB is – to our knowledge – unprecedented. The synthesis of complex (μ-H)2Ru3(CO)9{μ3-η2-[H2Cdouble bond; length as m-dashC(H)CCC(double bond; length as m-dashO)OCH3]} occurs through the activation of CO and methanol. This process has been found for other reactions of functionalized alkynes with M3(CO)12 carbonyls (M = Fe, Ru) under basic methanolic conditions. The known hydridic cluster, (μ-H)Ru3(CO)9[μ3-η3-(MeCCHCH)] has been identified as the minor reaction product.