Infrared Spectra of Insertion, Methylidene, and Methylidyne Complexes in Reactions of Laser‐Ablated Ruthenium Atoms with Halomethanes and Methane

Abstract

Reactions of laser-ablated Ru atoms with halomethanes and methane have been investigated. Small carbyne and carbene complexes or insertion products are produced in the reactions of halomethanes via C–X insertion and halogen migration, whereas only the insertion complex is formed in the reactions of methane. The results are consistent with computed product stabilities. The diagnostic C–H and C–X stretching absorptions of the carbyne complexes are observed on the blue side of the corresponding precursor bands. The high C–H and C–X stretching frequencies are explained with the higher s character in hybridization and combination with the C≡Ru stretching motion, respectively. The structures of the carbyne complexes are highly distorted and show a large variation with the ligands, and the extra electron pair on the Ru atom evidently plays an important role in the carbyne. In contrast to early transition-metal analogs, the Ru carbene complexes show no agostic distortion.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)