Vacuum Ultraviolet Photoelectron

Vacuum ultraviolet photoelectron spectroscopy of inorganic molecules. R. L. De Kock and D. R. Lloyd, Adv. Inorg. Chem. Radiochem., 1974,16, 66-107 (187). 

Vacuum Ultraviolet Photoelectron Spectroscopy of Inorganic Molecules R. L. DeKock and D. R. Lloyd... 

UH UPS UV-vis ultra-high vacuum ultraviolet photoelectron spectroscopy ultraviolet-visible ... 

J. M. Dyke, N. Jonathan and A. Morris, Int. Rev. Phys. Chem., 2, 3 (1982), summarize some Recent progress in the study of transient species with vacuum ultraviolet photoelectron spectroscopy . 

Another readily available monochromatic source uses the resonance lines of He I at 21.2 eV or He II at 40.8 eV, which have linewidths of about 0.005 eV. These are the major sources used in vacuum-ultraviolet photoelectron spectroscopy (UPS). Unfortunately, good photon sources with energies between 1000 and 40 eV are still not easily available. 

N. Sato, H. Inokuchi, K. Seki, J. Aoki, and S. Iwashima, Ultraviolet Photoemission Spectroscopic Studies of Six Nanocyclic Aromatic Hydrocarbons in the Gaseous and Solid States, J. Chem. Soc. Faraday Trans. 2 78, 1929-1936 (1982) N. Sato, K. Seki, and H. Inokuchi, Polarization Energies of Organic Solids Determined by Ultraviolet Photoelectron Spectroscopy, J. Chem. Soc. Faraday Trans., 2 77, 1621-1633 (1981) N. Sato, K. Seki, and H. Inokuchi, Ultraviolet Photoelectron Spectra of Tetrahalo-P-Benzo-quinones and Hexahalobenzenes in the Solid State, J. Chem. Soc. Faraday Trans. 2 77, 47-54 (1981) I. Ikemoto, Y. Sato, T. Sugano, N. Kosugi, H. Kuroda, K. Ishii, N. Sato, K. Seki, and H. Inokuchi, Photoelectron Spectroscopy of the Molecule and Solid of 11,11,12,12-Tetracyanonaphthoquinodimethane (TNAP), Chem. Phys. Lett. 61, 50-53 (1979) K. Seki, S. Hashimoto, N. Sato, Y. Harada, K. Ishii, H. Inokuchi, and J. Kanbe, Vacuum-Ultraviolet Photoelectron Spectroscopy of Hexatricontane (N-C36-H74) Polycrystal A Model Compound of Polyethylene, J. Chem. Phys. 66, 3644-3649 (1977). 

In vacuum ultraviolet photoelectron spectroscopy (UPS), the sample atom or molecule is exposed to radiation in the vacuum ultraviolet region of the electromagnetic spectrum. A readily available source of radiation is the helium discharge lamp, whieh produces a sharp Hel line at 21.2 eV. Since the energy required for photoionization of sets of valence electrons is in the vicinity of 6 eV to this energy, we obtain a polyenergetic emission of electrons described by the Einstein relation... 

FIGURE 24 Typical vacuum ultraviolet photoelectron (a), wide-scan X-ray photoelectron (b), and narrow-scan X-ray photoelectron (c) spectra. 

Hepburn J W 1995 Generation of coherent vacuum ultraviolet radiation applications to high-resolution photoionization and photoelectron spectroscopy Laser Techniques in Chemistry vol 23, ed A B Myers and T R Rizzo (New York Wley) pp 149-83... 

Fig. 9 OMT bands for NiOEP, associated with transient reduction (1.78 V) and transient oxidation (—1.18 V). Data obtained from a single molecule in a UHV STM. The ultraviolet photoelectron spectrum is also shown, with the energy origin shifted (by the work function of the sample, as discussed in [25]) in order to allow direct comparison. The highest occupied molecular orbital, n, and the lowest unoccupied molecular orbital, %, are shown at their correct energy, relative to the Fermi level of the substrate. As in previous diagrams,

Xu et al. used X-ray photoelectron spectroscopy (XPS), ultraviolet photoelectron spectroscopy (UPS), and X-ray magnetic circular dichroism (XMCD) spectroscopy to characterize the electronic and magnetic structure of Co deposited onto Alq3 films under high-vacuum conditions [35]. Eigure 4 shows the N(ls), 0(ls),... 

The electron, upon excitation, is ejected from an inner shell into vacuum and the energy of the free electron is then measured. This technique is called X-ray photoelectron spectroscopy. If the electron is ejected from the valence band by ultraviolet radiation, the technique is called ultraviolet photoelectron spectroscopy. Excitation energies not greater than those provided by ultraviolet radiation are necessary for electron excitation from the valence band or for electrons from the valence shell of adsorbed molecules. 

A study of the vacuum pyrolysis of 4-diazoisothiochroman-3-one with ultraviolet photoelectron spectroscopy has established the mechanism shown in Scheme 23 for its decomposition,103 while acid-catalysed hydrolysis of the same compound has been... 

Surface wave spectroscopy is still in its infancy, and most of the examples we have mentioned have been demonstrations of what can be done. It has clearly been demonstrated that vibrational and electronic spectroscopy can be done on molecules sorbed on metal substrates at less than monolayer coverages. In contrast to many techniques for surface spectroscopy (e.g. ultraviolet photoelectron spectroscopy, Auger electron spectroscopy), SEW spectroscopy does not require ultrahigh vacuum and can be done in the presence of reactant gases. This should make it a valuable tool for the study of catalytic reactions. Certainly... 

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