Reactions of ruthenium and rhodium atoms with carbon monoxide and dinitrogen mixtures: a combined experimental and theoretical study.

Laser-ablated Ru and Rh atoms react with CO and N(2) mixture in excess neon to produce the carbonylmetal dinitrogen complexes, (NN)(n)MCO (M=Ru,Rh; n=1,2) and NNRu(CO)(2), as well as metal carbonyls and dinitrogen complexes. These carbonylmetal dinitrogen complexes are characterized using infrared spectroscopy on the basis of the results of the isotopic substitution and mixed isotopic splitting patterns. Density functional theory calculations have been performed on these complexes. Overall agreement between the experimental and calculated vibrational frequencies, relative absorption intensities, and isotopic shifts supports the identification of these species from the matrix infrared spectra. Furthermore, a plausible reaction pathway for the formation of the products has been proposed. This work reveals that the reactivity of Ru and Rh atoms toward CO is prior to N(2).