Hans U. Stauffer, Ryan Z. Hinrichs, Jonathan J. Schroden, and H. Floyd Davis

The reactions of ground state yttrium atoms (Y) with formaldehyde (H₂CO) have been studied in crossed molecular beams as a function of collision energy (E_coll). At E_coll = 21 kcal/mole, reaction is initiated by C-H insertion producing HYCHO followed by H atom migration forming H₂YCO. Although Y-CO bond fission leading to HYH + CO is dominant, a secondary minor channel also leads to production of YCO + H₂. Formation of YCHO + H is not observed at a collision energy of 21 kcal/mole, but at E_coll = 31 kcal/mole, this channel is clearly seen, suggesting that D_o(Y-CHO) lies between 58 and 68 kcal/mole. Even at a collision energy of 12 kcal/mole, below the potential energy barrier for C-H insertion, the slightly endoergic reaction leading to YO + CH₂ is observed.