Zero kinetic energy electron spectroscopy

Zero electron kinetic energy spectroscopy provides a new tool in the study of chemical systems. In particular, it is applicable to molecules that are not in a bottle (metastable species) which nevertheless are of fundamental... 

Zero electron kinetic energy spectroscopy is based on the detection of low-kinetic-eneigy electrons and tuning of the laser wavelength X2... 

Yourshaw I, Zhao Y and Neumark D M 1996 Many-body effects in weakly bound anion and neutral clusters zero electron kinetic energy spectroscopy and threshold photodetachment spectroscopy of Ar Br" n = 2-9) and Ar r (n =... 

Zero Electron Kinetic Energy Spectroscopy, ZEKE... 

Abbreviations used in the tables calc = calculated value PT = photodetachment threshold using a lamp as a light source LPT = laser photodetachment threshold LPES = laser photoelectron spectroscopy DA = dissociative attachment attach = electron at-tachment/detachment equilibrium e-scat = electron scattering kinetic = dissociation kinetics Knud=Knudsen cell CT = charge transfer CD = collisional detachment and ZEKE = zero electron kinetic energy spectroscopy. 

ZEKE zero electron kinetic energy spectroscopy... 

You Yourshaw, I., Lenzer, Th., Reiser, G., Neumark, D.M. Zero electron kinetic energy spectroscopy of the KrBr, XeBr andKrCl anions, J. Chem. Phys. 109 (1998) 5247-5256. 

My question to Prof. Gerber is the following Could you please explain the different virtues of femtosecond pump-pulse experiments versus ultrashort zero electron kinetic energy (ZEKE) spectroscopy Do they yield complementary information on the molecular dynamics or are there specific domains where one of them should be preferred with respect to the other ... 

D. -S. Yang, M. Z. Zgierski, D. M. Rayner, P. A. Hackett, A. Martinez, D. R. Salahub, P.-N. Roy, and T. Carrington Jr., J. Chem. Phys., 103, 5335 (1995). The Structure of NbjO and Nb30 Determined by Pulsed Field Ionization-Zero Electron Kinetic Energy Photoelectron Spectroscopy and Density Functional Theory. 

The fourth technique for electron analysis measures a preselected set of zero or nearly-zero kinetic energy. While first known as TPE spectroscopy, when monochromatic synchrotron light was used, the addition of pulsed, tunable lasers has led to a totally new, extremely promising branch of PES, termed zero electron-kinetic-energy (ZEKE) PES or ZEKE spectroscopy18. We will describe it in detail later. 

ADE = adiabatic detachment energies ESC A = electron spectroscopy for chemical analysis HOMO = highest occupied molecular orbitals MAES = metastable atom electron spectroscopy MIES = metastable ionization electron spectroscopy OAT = oxygen atom transfer PES = photoelectron spectra PEI = pulsed field ionization PIES = Penning ionization electron spectroscopy QM = quantum-mechanical REMPI = resonantly enhanced multiphoton ionization SC = semiclassical VDE = vertical detachment energies XPS = x-ray photoelectron spectroscopy ZEKE = zero electron kinetic energy Cp = cyclopentadienyl, Ph = phenyl, CeHs Tp =... 

Using zero electron kinetic energy photoelectron spectroscopy, the structures of Nb3N2 and its cation were assigned as C2v. The two N atoms bridge two sides of an isosceles triangle of Nb atoms.603 Similar conclusions have been drawn for the Nb3C2 system and for [M30]x (x = — 1, 0, + 1).604... 

The improved numerical stability of the new deMon2K version also opened the possibility for accurate harmonic Franck-Condon factor calculations. Based on the combination of such calculations with experimental data from pulsed-field ionization zero-electron-kinetic energy (PFl-ZEKE) photoelectron spectroscopy, the ground state stmcture of V3 could be determined [272]. Very recently, this work has been extended to the simulation of vibrationaUy resolved negative ion photoelectron spectra [273]. In both works the use of newly developed basis sets for gradient corrected functionals was the key to success for the ground state stmcture determination. These basis sets have now been developed for aU 3d transition metal elements. With the simulation of vibrationaUy resolved photoelectron spectra of small transition metal clusters reliable stmcture and... 

Two especially important variants of REMPI (Johnson, et al., 1975) spectroscopy are ionization-dip (Cooper, et al., 1981) and Zero Electron Kinetic Energy (ZEKE) (Miiller-Dethlefs and Schlag, 1991 Merkt, 1997 Signorell and Merkt, 1999) photoelectron spectroscopy. Ionization-dip REMPI spectroscopy is especially useful when one wants to record free<—bound spectra from a single, selectable v, J level. Without such v, J selection, most of the oscillatory structure in a free<—bound spectrum will be washed out. One potential problem with some ionization-dip schemes is that, if the ionization transition originates from the initial level of the free<—bound transition being studied, there is a possibility that the observed linewidths will be distorted by power broadening (especially when the free final state is a weakly predissociated state with linewidth < lcm-1). 

Observation of vibrational structure in the PE spectra of large organometallic molecules is rare because of the large number of vibrational modes that may be excited, the low frequencies of many of the vibrational modes, and the lack of resolution in conventional spectrometers. Techniques such as zero electron kinetic energy (ZEKE) spectroscopy have been successful in resolving vibrational structure on small molecules but have not been successfully extended to organometallics as yet. Those spectra that show vibrational structure have proved informative. 

LASER-BASED PULSED FIELD IONIZATION-ZERO ELECTRON KINETIC ENERGY PHOTOELECTRON SPECTROSCOPY... 

ZEKE (zero kinetic energy) photoelectron spectroscopy has also been applied to negative ions [M]. In ZEKE work, the laser wavelengdi is swept tlirough photodetachment thresholds and only electrons with near-zero kinetic energy are... 

Time-of-flight mass spectrometers have been used as detectors in a wider variety of experiments tlian any other mass spectrometer. This is especially true of spectroscopic applications, many of which are discussed in this encyclopedia. Unlike the other instruments described in this chapter, the TOP mass spectrometer is usually used for one purpose, to acquire the mass spectrum of a compound. They caimot generally be used for the kinds of ion-molecule chemistry discussed in this chapter, or structural characterization experiments such as collision-induced dissociation. Plowever, they are easily used as detectors for spectroscopic applications such as multi-photoionization (for the spectroscopy of molecular excited states) [38], zero kinetic energy electron spectroscopy [39] (ZEKE, for the precise measurement of ionization energies) and comcidence measurements (such as photoelectron-photoion coincidence spectroscopy [40] for the measurement of ion fragmentation breakdown diagrams). 

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