H. Ikeura-sekiguchi et al., Site-specific ion desorption from condensed C- and N-deuterated formamide near the carbon and nitrogen K-edge, SURF SCI, 454, 2000, pp. 407-411
Ion desorption from two types of condensed deuterated formamide was studied
by site-specific core-electron excitation, Excitation of C 1s electron int
o sigma* (C-D/N-H) antibonding orbital of condensed DCONH2 shows a very hig
h desorption yield of D+ through the selective C-D bond fission. In contras
t, no resonant peak was observed at the C 1s-->sigma* (C-D/N-H) excitation
of condensed HCOND2. Excitation of N 1s electron into sigma* (C-H/N-D) anti
bonding orbital of condensed HCOND2 relatively enhances the desorption yiel
d of D+ compared with the total electron yield corresponding to the photoab
sorption cross-section, whereas the desorption yield of DC was not enhanced
at the N 1s-->sigma* (C-D/N-H) excitation of condensed DCONH2. Ion desorpt
ion from condensed formamide thus depends on the antibonding character of t
he excited state and also occurs around the chosen atomic site where the co
re-electron excitation takes place. (C) 2000 Elsevier Science B.V. All righ
ts reserved.