| 1. |
- Ottosson, Niklas, et al.
(författare)
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An electronic signature of hydrolysation in the X-ray absorption spectrum of aqueous formaldehyde
- 2008
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Ingår i: Chemical Physics Letters. - : Elsevier BV. - 0009-2614 .- 1873-4448. ; 460:4-6, s. 540-542
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Tidskriftsartikel (refereegranskat)abstract
- Formaldehyde in aqueous solution is hydrolysed and forms methanediol. Using X-ray absorption spectroscopy we show that the hydrolysation product can be identified by a distinct electronic signature in the spectra. This is manifested by the disappearance of the oxygen 1s -> ; pi* absorption line. The X-ray absorption spectrum of aqueous formaldehyde is compared with those of the structurally similar formamide and urea, which are in contrast not hydrolysed in aqueous solution. We thereby demonstrate the exceptional sensitivity and simplicity of the technique to monitor this fundamental process in the aqueous phase.
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| 2. |
- Rosso, Aldana, et al.
(författare)
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Photoelectron spectroscopy study of free potassium clusters : core level lines and plasmon satellites
- 2008
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Ingår i: Physical Review A. Atomic, Molecular, and Optical Physics. - 1050-2947 .- 1094-1622. ; 77:4, s. 043202(1)-043202(5)
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Tidskriftsartikel (refereegranskat)abstract
- Free neutral potassium clusters of two different mean sizes were produced using a gas aggregation source. The K 3p core level was probed by means of synchrotron radiation based photoelectron spectroscopy. The absolute binding energy and the intensity ratio of the surface and bulk spectral features were used to obtain independent estimates of the cluster size. Plasmon satellites in core level spectra of free metallic clusters were observed. Surface and bulk plasmon energies were determined. The interplay between the core line and plasmon integrated intensities is discussed.
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| 3. |
- Rosso, Aldana, et al.
(författare)
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The valence band of free K clusters studied by photoelectron and Auger spectroscopies
- 2008
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Ingår i: European Physical Journal D. - : Springer Science and Business Media LLC. - 1434-6060 .- 1434-6079. ; 50:2, s. 165-169
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Tidskriftsartikel (refereegranskat)abstract
- The valence states of free neutral potassium clusters produced by a gas aggregation source were probed by synchrotron radiation based photoelectron spectroscopy. The first ionization energy (IE) of the clusters was determined to be 10% larger than the work function of bulk potassium. Using electrostatic concepts and the IE, the mean size of the clusters was estimated to be ≈2000 atoms. Further information about the valence band was provided by investigation of the Auger process initiated by the ionization of the 3p level with a subsequent emission of an Auger electron from the valence band (M2,3VV). Plasmon satellites were observed in Auger spectra of free metal clusters.
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| 4. |
- Tchaplyguine, Maxim, et al.
(författare)
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Absolute core-level binding energy shifts between atom and solid: The Born-Haber cycle revisited for free nanoscale metal clusters
- 2008
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Ingår i: Journal of Electron Spectroscopy and Related Phenomena. - : Elsevier BV. - 0368-2048 .- 1873-2526. ; 166, s. 38-44
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Tidskriftsartikel (refereegranskat)abstract
- Core-level binding energy shifts between the free atom and corresponding large clusters, the latter closely approximating the infinite solid, have been experimentally derived for several elemental metals. The cluster core-level binding energies in question have been determined relative to the vacuum level using synchrotron-based photoelectron spectroscopy. As expected, the experimental shift values show reasonable agreement with those calculated using the thermochemical Born–Haber cycle approach. The largest uncertainty factors defining the discrepancies between the experiment and the model, such as the difference in the multiplet structure of free atoms and the solid, the in some cases indirectly established cluster work functions, and the metal solvation energy, are discussed.
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