(Color online) (a) Staggered and (b) eclipsed Cr(η6-C6H6)2; (c) experimental UPS data for Cr(η6-C6H6)2 vapor (hν = 30 eV) from Ref. 16 (with permission). The binding energy reference is the vacuum level. The very sharp features are artifacts incurred during digitization of the published spectrum.
ELS data at 100 K for (a) clean HOPG, (b) a thick layer of benzene ice, (c) after deposition of ∼0.20 ML of Cr, and (d) after deposition of ∼0.20 ML of V. The spectra have been scaled for equal intensity in the elastic peak and have been displaced vertically for clarity. The arrows mark some of the features discussed in the text.
ELS vs annealing for VBz2. In each case, the sample is raised to the temperature indicated and then returned to 100 K for data collection. The 168 K spectrum is the same as that shown in Fig. 2(d) . The spectra have been scaled for equal intensity in the elastic peak and have been displaced vertically for clarity.
UPS data (a) for bare HOPG, (b) after condensation of a layer of Bz ice, (c) after deposition of ∼0.16 ML of Cr on top of Bz ice, and (d) after deposition of ∼0.25 ML of V on Bz ice. All data are for HeII excitation (hν = 40.81 eV) at a sample temperature of 100 K, and binding energies are referenced to the Fermi level. The spectra have been displaced vertically for clarity. Nonzero emission above the HOMO in (b) is due to higher-energy satellites in the HeII spectrum. The off-scale emission at the high-BE end is due to excitation by the main HeI line at hν = 21.22 eV. The features marked with an asterisk in (c) and (d) may be due in part to excitation of the HOMO by the HeI satellite at hν = 23.09 eV (see text). The lines connecting (b) and (c) illustrate the correlation between features in the Bz multilayer and the CrBz2 monolayer.
(a) UPS data for a thin film (approximately one close-packed layer) of toluene on HOPG. (b) After deposition of ∼0.10 ML of Cr at 100 K to form Cr(Tol)2. The arrows and the connecting line identify features discussed in the text.
(a) UPS for CrBz2 (100 K, hν = 40.81 eV). (b) Computed DOS for the free CrBz2 molecule. (c) Same as (b) but for the molecular cation. Both calculated spectra have been shifted in energy to bring the peak at 10.0 eV into approximate alignment with the experimental spectrum. This obscures any shift between the neutral and the cationic molecules and was done in order to make clear the relative shifts in the HOMO and HOMO-1. Note that [CrBz2]+ and VBz2 are isoelectronic.
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