K-edge near-edge x-ray-absorption fine structure of oxygen- and carbon-containing molecules in the gas phase

The carbon and oxygen K-edge near-edge x-ray absorption fine structures (NEXAFS) of a series of molecules, carbon monoxide (CO), carbon dioxide (${\mathrm{CO}}_2$), carbonyl sulfide (OCS), acetone [(${\mathrm{CH}}_3$ ${)}_2$CO], ethanol (${\mathrm{C}}_2$ ${\mathrm{H}}_5$OH), diethylether [(${\mathrm{C}}_2$ ${\mathrm{H}}_5$ ${)}_2$O], tetrahydrofuran (${\mathrm{C}}_4$ ${\mathrm{H}}_8$O), and p-dioxane (${\mathrm{C}}_4$ ${\mathrm{H}}_8$ ${\mathrm{O}}_2$) have been recorded in the gas phase in transmission, total-ion-yield, and luminescence-yield modes. The results are compared with previous measurements and theoretical predictions, and discussed generally on the basis of molecular structure and bonding. The the NEXAFS parameters are examined in terms of the electron-core-hole interaction, spatial characteristics of the final states, correlation with interatomic distance, and multiple-scattering phenomena.