Matrix Infrared Spectroscopic and Theoretical Studies on the Reactions of Scandium, Yttrium, and Lanthanide Metal Atoms with Dimethyl Ether

Reactions of laser-ablated scandium, yttrium, lanthanum, and several lanthanide metal atoms with dimethyl ether have been studied using matrix isolation infrared spectroscopy. Identifications of the major products, M(CH3OCH3) and CH3OMCH3 (M = Sc, Y, La, Ce, Gd, Tb, Yb, and Lu), are supported by experiments with deuterium substitution as well as theoretical calculations. It is found that most ground-state metal atoms react with dimethyl ether to give:the M(CH3OCH3) complexes spontaneously on annealing, which isomerize to the CH3OMCH3 insertion products with visible irradiation. Density functional calculations reveal that the M(CH3OCH3) complexes possess C-2v symmetry with metal atoms bound to the oxygen side of dimethyl ether, and bent geometries are found for the inserted CH3OMCH3 Molecules with direct M-O and C-O bonds. All of these products have the same ground states as their corresponding metal atoms except for Tb. Although the Lu(CH3OCH3) complex is predicted to be a stable molecule, it is not observed in the experiment due to the low energy barrier for the subsequent C-O bond insertion reaction.