Water electron detachment energy

N. Mikami, Infrared spectroscopic evidence for protonated water clusters forming nanoscale cages, Science 304, 1134-1137 (2004). (e) S. B. Suh, H. M. Lee, J. Kim, J. Y. Lee, and K. S. Kim, Vibrational spectra and electron detachment energy of the anionic water hexamer,... 

J. M. Herbert and M. Head-Gordon,/. Phys. Chem. A, 109, 5217-5229 (2005). Calculation of Electron Detachment Energies for Water Cluster Anions An Appraisal of Electronic Structure Methods, with Application to (H2 0)J j and (H2 0)J. ... 

Electron detachment (5-126) together with dissociative attachment (5-125) creates a chain reaction of water decomposition. One electron is able to participate in the H2O dissociation process many times in this case, which makes the whole kinetic mechanism energy effective. Cross sections of the electron detachment by electron impact (5-126) are shown in Fig. 5-58 a typical value of rate coefficient for the detachment process is very high (kd = 10 cm /s Smirnov Chibisov, 1965 Tisone Branscome, 1968 Inocuti et al., 1967). The chain mechanism, (5-125) and (5-126), is initiated by ionization of H2O molecules. The chain termination is related to fast ion-ion recombination,... 

Absorption of UV or visible light from a flash lamp or a laser is used to produce the solvated electron, too. Two photolytic processes may occur (1) the photon energy is sufficient to ionize a solute and produce the electron, for instance, photo-detachment from an anion (Cl , Fe(CN)g , Na ...) (2) the laser intensity is high enough to induce ionization of the solvent via multiphoton absorption (e.g. HjO -I- hv 112 + e ). For water, at least 8 eV is needed to ionize the solvent. 

The plasma-chemical process that is based on dissociative attachment can become energy effective only if the same electron is able to participate in a reaction many times. In such a chain reaction, the detachment and liberation of the electron from a negative ion should be faster than the loss of the charged particle in ion-ion recombination. Water vapor dissociation in non-thermal plasma is an example of such a chain process. This plasma-chemical reaction is to be considered in detail in Sections 5.8.4 and 5.8.5. The energy efficiency of the chain process for this reaction can be relatively high 40-50%. 

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