Infrared Spectra of CH₃–MX and CH₂X–MH Prepared in Reactions of Laser-Ablated Gold, Platinum, Palladium, and Nickel Atoms with CH₃Cl and CH₃Br

Au, Pt, Pd, and Ni insertion complexes have been produced in reactions with methyl chloride and bromide. The primary products are identified in the matrix IR spectra on the basis of deuterium shifts in the vibrational frequencies and correlation with DFT calculated frequencies. However, fragments of the insertion complexes and the higher oxidation state derivatives, which have been observed in previous studies for reactions with methane and fluoromethane, were not detected. The Pt C–H insertion complex (CH₂Cl–PtH) is also produced, parallel to the fluorinated analogue. The observed Pt and Pd products have highly bent CMX­(H) moieties, which are traced to the unusually high d orbital contributions from the metal atom to the C–M and M–X­(H) bonds.