Site-specific ion desorption from condensed C- and N-deuterated formamide near the carbon and nitrogen K-edge

Ion desorption from two types of condensed deuterated formamide was studied by site-specific core-electron excitation. Excitation of C 1s electron into σ∗ (CD/NH) antibonding orbital of condensed DCONH2 shows a very high desorption yield of D+ through the selective CD bond fission. In contrast, no resonant peak was observed at the C 1s→σ∗ (CD/NH) excitation of condensed HCOND2. Excitation of N 1s electron into σ∗ (CH/ND) antibonding orbital of condensed HCOND2 relatively enhances the desorption yield of D+ compared with the total electron yield corresponding to the photoabsorption cross-section, whereas the desorption yield of D+ was not enhanced at the N 1s→σ∗ (CD/NH) excitation of condensed DCONH2. Ion desorption from condensed formamide thus depends on the antibonding character of the excited state and also occurs around the chosen atomic site where the core-electron excitation takes place.