Ion ranges

To discuss the analytical approach to estimating ion ranges, the concept of reduced energy must first be introduced. The reduced energy S is given by equation 3 ... 

The accurate treatment of ion ranges in compound targets requires extensive calculations and is most accurately handled by simulation programs... 

M. A. Kunakhov and F. F. Komarov, Energy Eoss and Ion Ranges in Solids Gordon and Breach Science PubHshers, New York, 1981. 

The preferred ratio of cuprous to cupric ion ranges from 5 1 to 10 1, depending on system conditions. Too high a concentration of cuprous ion causes the system to disproportionate and form metallic copper (eq. 26) ... 

Whereas the reduction potentials for the three metal ions range from +0.19V vs NHE(Cu) to +1.58V(Au), the potentials for oxidation of OH in their presence are -0.79V vs NHE(Cu), -0.30V(Ag), and -0.19V(Au). This is compatible with the proposition that oxidation occurs via the facilitated removal of an electron from OH and formation of an M-OH covalent bond. The only exception to the close agreement between gas-phase and redox-derived M-OH bond energies is the Cu-OH bond energy from aqueous redox data. This may be due to an inaccurate formal potential for the CuOH/Cu, OH couple (a value of 0.0V vs NHE rather than -0.36V would result in a more consistent bond-energy estimate). 

Figure 10.3 Whole-mass analysis of a monoclonal antibody. (A) Direct infusion of the antibody generates an envelope of high m/z ions ranging from 2000 to 3500. Deconvolution of the ion current signal gives the mass of the complete native molecule (147, 100.97 Da) and resolves some heterogeneity linked to the A-glycan structures. The major forms are consistent with molecules carrying biantennary structures capped with 0, 1, or 2 hexose (G = galactose) residues. (Data generated on an ESI-Q-Star instrument, Sciex-Applied Biosystems.)...

Fig. 2.20. High resolution photoelectron spectrum of O2, showing overlapping vibrational progressions from transitions to different electronic states of the ion (range of IE not shown). Reproduced from Ref. [88] with permission. Royal Swedish Academy of Sciences, 1970.

Example The high-resolution spectrum in the molecular ion range of a zirconium complex is typified by the isotopic pattern of zirconium and chlorine (Fig. 3.22). Zr represents the most abundant isotope of zirconium which is accompanied by Zr, r, Zr and Zr, all of them having considerable abun-... 

However, a much coarser approach can yield significant results. Several authors, for example, have attempted to relate the kinetic-secondary-electron coefficient to the stopping-power relationships used for the analysis of atomic ion ranges in solids. A very lucid paper on this approach has been presented by Beuhler and Friedman and their perspective will be summarized in the following paragraphs. 

Hydrogen atoms in azolium ions can be removed easily as protons (e.g. 300— 302) exchange with deuterium occurs in heavy water. The intermediate zwitterion (e.g. 301) can also be written as a carbene. The pKa values of thiazolium ions range from 16 to 20 (87CRV863, 88B5044). 

The coordination numbers of metal ions range from I, as in ion pairs such as Na CI- in the vapor phase, to 12 in some mixed metal oxides. The lower limit, I. is barely within the realm of coordination chemistry, since the Na+CI km pair would not normally be considered a coordination compound, and there are few other examples. Likewise, the upper limit of 12 is not particularly important since it is rarely encountered in discrete molecules, and the treatment of solid crystal lattices such as hexagonal BaTiOj and perovskite1 as coordination compounds is not done frequently. The lowest and highest coordination numbers found in typical coordination compounds are 2 and 9 with the intermediate number 6 being the most important. 

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