NIPES

From these results, the CDF form internal events is dominated by r "idents invoivine nipe... 

In negative ion photoelectron spectroscopy (NIPES), the reactant is a negative ion, and the upper state is neutral. In this case, the origin can be used to determine the electron affinity. 

Remarkably, the photoelectron spectrum provides more than just the energy of the transition state. As can be seen in Figure 5.5, the spectrum also contains peaks corresponding to the transition state in excited vibrational levels, where the activated vibrations are orthogonal to the reaction coordinate. Therefore, NIPES can even be used to carry out vibrational spectroscopy of reaction transition states. 

Pershad, H. R., Duff, J. L., Heering, H. A., Duin, E. C., Albracht, S. P., and Armstrong, F. A., 1999, Catalytic electron transport in chromatium vinosum [NiPe]-hydrogenase application of voltammetry in detecting redox-active centers and establishing that hydrogen oxidation is very fast even at potentials close to the reversible H(+)/H(2) value [In Process Citation], Biochem. 38(28) 8992n8999. 

Ion cyclotron resonance (ICR) and flowing afterglow experiments can also be used to derive relative affinities. Neutral beam experiments, where a beam of alkali atoms such as Cs is crossed with a beam of molecules such as PCI3 or (012)2 have been used to derive thermochemistry for anions such as PCli" and Cli", but proper analysis of this type of data is difficult. High-resolution negative ion photoelectron spectroscopy (NIPES) experiments can provide otherwise unobtainable information on hypervalent anions, including precise electron affinities and vibrational frequencies.This technique has limited applicability to hypervalent species with more than three atoms because of vibrational congestion from low-frequency modes. 

To overcome this problem we recently suggested to correlate the ionization potential (IP) and the electron affinities (EA) of carbenes with the carbene philicity. [14] IP and EA of carbenes can in principle be measured by negative ion photoelectron spectroscopy (NIPES), and data of a series of simple carbenes and vinylidenes were published by Lineberger et al. [15-23] The experimental data allow to evaluate the reliability of theoretical methods for the calculation of IP and EA. As shown in Table 1, there is a decent agreement between the experimental EA and calculations of the vertical EA of carbenes. The calculated adiabatic EAs are systematically too large by ca. 0.3 eV. However, if the adiabatic EAs are corrected by this value the agreement with the experiment is even better. 

Carbene NIPES EA B3LYP EAfcali , ail] B3LYP vert., i uutriil] B3LYP EAfi ale, vert., aniiTn)... 

Experimental EA from negative ion photoeleetron speetroseopy (NIPES). EAcalculated at the B3LYP/6-311-H-G(d,p) level of theory. Adiabatie EA. EA at the geometry of the neutral earbene. EA at the geometry of the anion. 

Yoon MA, Jeong TS, Park DS, Xu MZ, Oh HW, Song KB, et al. Antioxidant effects of quinoline alkaloids and 2,4-di-tert-butylphenol isolated from Scolopendra subspi-nipes. Biol Pharm Bull 2006 29(4) 735-9. 

The compositions of the described electron transport chains show participations of similar NiPe hydrogenases and similar polysulfide sulfur reductases in the case of W. succinogenes and A. ambivalens, whereas the sulfur reductase of P. abyss may be different. In this microorganism the electron transfer between the hydrogenases and the polysulfide sulfur reductases mediated by 8-methyl-menaquinone, sulfolobusquinone or cytochromes b and c, respectively, seems to be adapted to the synthesis capabilites of the species. 

Gliubich F, Gazerro M, Zanotti G, Delbono S, Bombieri G, Bemi R (1996) Active site structural features for chemically modified forms of rhodanese. J Biol Chem 271(35) 21054-21061 Li S, Hall MB (2001) Modeling the active sites of metalloenzymes. 4. predictions of the unready states of [NiPe] desulfovibrio gigas hydrogenase from density functional theory. Inorg Chem 40(l) 18-24... 

Because nuclides of iron are especially stable with the highest binding energy per nucleon (e.g., -8.79 MeV/nucleon for Fe), its cosmic abundance is particularly high, and it is thought to be the main constituent of the Earth s inner core as an iron-nickel alloy (see Section 13.2), named for its chemical composition NiPe by the Austrian geophysicist Suess. The relative Earth s crust abundance is about 5.63 wt.% Fe hence it is the fourth most abundant element after oxygen, silicon, and aluminum and the second most abundant metal after aluminum. 

Ps NiPe N2PE here Nj and - number of homogeneous atoms in subsystems. 

Gilberto De Martino Jannuzzi (energy for sustainable development). Center for Energy Studies (NIPE), University of Campinas (UNICAMP), Campinas, SP... 

When considering nonstoichiometry in ternary compounds it is possible to have two types of defects in excess. Two examples are nickel ferrite, where both O vacancies and Ni atoms on Fe sites occur (Nipe) to give a compound whose overall composition is... 

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