Formation of a Simple Hafnium Methylidene Complex by Reaction of Methyl Fluoride with Laser-Ablated Hafnium Atoms

The methylidene hafnium complex (CH 2 HfHF) is formed by reaction of methyl fluoride with laser-ablated hafnium atoms and isolated in a solid argon matrix. The higher Hf−H and C−Hf stretching frequencies for CH 2 HfHF than those of CH 2 ZrHF are attributed to the shortened bonds for the heavier metal atom owing to relativistic effects. The singlet CH 2 HfHF ground state molecule shows evidence of an α-hydrogen agnostic interaction. In contrast to the cases of Ti and Zr, the most likely initial CH 3 −HfF intermediate was not trapped in the matrix, as α-hydrogen shift led directly to the CH 2 HfHF product.