Alkali metals photoelectrons from

Photoelectron spectroscopy involves the ejection of electrons from atoms or molecules following bombardment by monochromatic photons. The ejected electrons are called photoelectrons and were mentioned, in the context of the photoelectric effect, in Section 1.2. The effect was observed originally on surfaces of easily ionizable metals, such as the alkali metals. Bombardment of the surface with photons of tunable frequency does not produce any photoelectrons until the threshold frequency is reached (see Figure 1.2). At this frequency, v, the photon energy is just sufficient to overcome the work function

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X-Ray photoelectron spectroscopy of the N(ls) core-electron binding energies of azides containing the alkali metals indicates that the electronic structure of the Nj ion is largely unchanged from compound to compound, and the differing thermal stabilities cannot be explained on the basis of different electronic structure. The N(ls) spectrum consists of two peaks in the vicinity of 398.5—404.9 eV separated by ca. 4.4 eV, as shown in the upper part of Table 6. The peak for terminal N is slightly broader than that... 

In the late 1960s several major advances were made in the study of thermal electron reactions. These were based on the ECD, the extension of the magnetron method of studying electron molecule reactions to determine equilibrium constants for electron molecule reactions, and the invention of high-pressure thermal electron negative-ion sources for mass spectrometry [5-7], Electron swarms were also used to determine rate constants for thermal electron reactions [8, 9]. The electron affinities of molecules were measured using electron and alkali metal beams [10, 11]. Relative electron affinities were obtained from the direction of the reaction of a negative ion with a molecule [12, 13], Other major advances were photodetachment and photoelectron spectroscopy [14—17],... 

Carbon. - Stimulated Raman pumping-anion photoelectron spectroscopy showed that the l<-0 vibrational transition of C2 is at 1757.8 + 0.1 cm h For M2C2, where M = Rb or Cs, the [C2] anion vCC mode is at 1807 cm (Rb, orthorhombic), 1805 cm (Rb, hexagonal) or 1796 cm (Cs). These values are consistent with trends from the lighter alkali metal analogues. ... 

The photoelectron microscopy results described above were necessarily acquired in vacuum. Under such conditions there is no doubt that the Na is present on the Pt surface as sodium metal. However, under reaction conditions, this cannot be the case it is to be expected that the alkali would be present as a submonolayer quantity of surface compound, and indeed this is just what is observed. Furthermore, also in accordance with expectation, the nature of the alkali promoter compound is dependent on the composition of the gas atmosphere. Figure 7 shows postreaction XPS and XANES spectra acquired from Pt/Na P" alumina EP samples after exposure to reaction conditions and without exposure to laboratory atmosphere for the Pt-catalyzed reactions NO-fpropene [Figure 7(a)] and 02-fpropene [Figure 7(b)], respectively. In the first case the promoter phase consists of a mixture of NaN02 and NaNOs, in the second case it consists of Na2C03. This is important... 

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