Unexpected coupling of Cp and two RNC ligands at a {Mo-2(mu-SMe)(3)} nucleus

Reaction of the bis-isonitrile complex [Mo-2-Cp-2(mu-SMe)(3)(t-BuNC)(2)](BF4) (1) with n-BuLi (in hexane) produced the dealkylated derivative [Mo2Cp2(mu-SMe)(3)(t-BuNC)(CN)] (2) in quantitative yield. However, upon treatment with either NaOH (suspension) or (Me4N)OH (in MeOH), 1 was converted into a mixture of 2 and the mu-alkylidyne species [Mo2Cp(mu-SMe)(3){mu-(eta(5)-C5H4)(t-BuN)-CN(t-Bu)C}] (3), in which a deprotonated Cp and both isonitrile ligands of 1 are now linked by new carbon-carbon and carbon-nitrogen bonds.