Potassium binding energy

Zhang, J. Dyachova, E. Ha, T.-K. Knochenmuss, R. Zenobi, R. Gas-phase potassium binding energies of MALDI matrices, an experimental and theoretical study. J. Phys. Chem. A 2003, 107, 6891. 

Potassium cation affinities of several azoles and other compounds in the gas phase were calculated by hybrid density functional theory [B3-LYP with 6-311 + G(3df, 2p) basis set] <2003CEJ3383>. There is a striking difference in binding energies of 177- and 277-1,2,3-triazoles. Some of the collected data are as follows ... 

Figure 3.20 UPS spectra of CO chemisorbed on iron show that the 5a orbital has shifted down to higher binding energy as a result of chemisorption. CO largely desorbs from clean iron upon heating to 390 K. Potassium enhances the bond between CO and the metal and promotes the dissociation of CO at higher temperatures (adapted from Broden et al. [51 ]).

Figure 9.11 Promoter-induced binding energy shifts of Ar, Kr and Xe photoemission peaks with respect to adsorption on the clean metal as a function of the distance of the adsorption site to the nearest potassium atom on a potassium-promoted Rh( 111) surface. These curves reflect the variation of the surface potential (or local work function) around an adsorbed potassium atom. Note the strong and distance-dependent local work function at short distances and the constant local work function, which is lower than that of clean Rh( 111) at larger distances from potassium. The lowering at larger distances depends on the potassium coverage. The averaged distances between the potassium atoms are 1.61, 1.32 and 1.20 nm for coverages of 2.7, 4.1 and 5.0% respectively, vertical lines mark the half-way distances. Lines are drawn as a guide to the eye (adapted from Janssens et al. [38]).

Figure 6.25. Valence band photoemission spectra of 1 ML Ceo on a Ag(lOO) surface as a function of potassium doping. Also shown are the spectra of the clean Ag(lOO) surface and of a Ceo multilayer (bottom). All binding energies are referred to the L f of polycrystalline silver. Reprinted from Surface Science, Vols. 454-456, C. Cepek, M. Sancrotti, T. Greber and J. Osterwalder, Electronic structure of K doped Ceo monolayers on Ag(OOl), 467 71, Copyright (2000), with permission from Elsevier.

Fig. 9.n Promoter-induced binding energy shifts of Ar, Kr and Xe photoemission peaks with respect to adsorption on the clean metal as a function of the distance of the adsorption site to the nearest potassium atom on a potassium-promoted Rh(lll) surface. These curves reflect the variation of the surface potential (or local work function) around an adsorbed potassium atom. Note the strong and distance-dependent local work function... 

Table II shows comparisons of data for several cured PI5878 samples. For the KOH treated sample that had no acetic acid rinse, bulk gotassium diffused to the surface on direct heat curing to 280 C. Though the data given reflect in situ results, the same phenomenon occurred in air or nitrogen ambients with virtually no change in the carbonyl binding energies for the sample. By contrast, the non-KOH treated sample and the treated surface that had a 5 minute acetic acid rinse showed identical C Is features - imide and "partially oxidized" carbon functionalities. The results demonstrate that potassium incorporated in the polyamic acid matrix prevents the imidization process.

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