A computational study on the reaction of yttrium with ketene

Abstract

The reaction of yttrium ( 2D) with ketene (H 2CCO) examined recently in crossed molecular beam experiments has been studied at B3LYP and CCSD (T) level. After the formations of different π-complexes with Y binding to C C O, C C and C O sites, respectively, several reaction channels are open. Two possible H-elimination pathways have been identified and they were found to correlate with singlet ground state and triplet excited state product, 1 YCHCO and 3 YCHCO, respectively. Three possible H 2-elimination pathways have been identified, and the calculation results indicate that the two concerted pathways can be competing processes at low energy, while the step-wise mechanism needs higher collision energy. The experimentally observed products YCCO were found to exist in two different forms (cyclic and linear). The calculated barrier of Y insertion into C C bond leading to the dominant product YCH 2 at low collision energy in CMB study is only 2 kcal/mol and the potential energy surface of this reaction is flat. In addition, the insertion of Y into C O bond was also identified, but this reaction is correlated to the product (vinylidene H 2CC) with excited state, agreeing with the fact that the formation of YO+H 2CC was not observed in experiment.