Infrared spectra of CH(2)=Zr(H)NC, CH(3)-ZrNC, and eta(2)-Zr(NC)-CH(3) produced by reactions of laser-ablated Zr atoms with acetonitrile.

The zirconium methylidene isocyanide, methyl isocyanide, and eta(2)-nitrile-pi-complexes are observed in the matrix IR spectra from reactions of laser-ablated Zr atoms and acetonitrile isotopomers. The methylidene CH(2)=Zr(H)NC has a C(1) agostic structure in line with simple early transition-metal methylidenes recently produced from reactions with small alkanes and methyl halides, and the extent of agostic distortion is also comparable. Formation of the isocyanide complexes from acetonitrile is interesting but not surprising according to previous studies of metal reactions with nitrile-containing compounds, and their stabilities over the cyanide species are reproduced by DFT calculations. Observation of the relatively rare nitrile pi-complex and its photodissociation suggests that the reaction proceeds in the order of Zr<--NCCH(3), eta(2)-Zr(NC)-CH(3), CH(3)-ZrNC, and CH(2)=Zr(H)NC. The intermediate transition-state structures are also examined.