Site- and State-Selective Dissociation of Core-Excited Organic Molecules: Deuterium-Labeled Methyl Acetate

Abstract

Site- and state-selective dissociation of methyl acetate induced by core level excitation has been studied in the oxygen K-edge region using time-of-flight fragment-mass spectroscopy. O1s core to valence excitation bands in the total-ion-yields of methyl acetate were assigned based on the comparison with those of other esters and band-deconvolution analysis. Product branching ratios of and CDO+ cations from deuterium-labeled methyl-d3 acetate (CH3C(O)OCD3) showed that site-selective bond scission takes place between the (O1sCO-1 π* CO and sites, indicating the dissociation with an antibonding nature after the spectator Auger transitions. Although the efficient production of CDO+ was observed at the () transition, however, no apparent state-selective dissociation of could be observed at the . The present results indicate that the lack of state-selectivity at the is largely due to the weak band intensity buried into the congestion of core-to-Rydberg transitions.