Photoelectron gaseous phase

The gaseous phase photoelectrons are created within the Volta potential field and they will thus not experience its full effect but only about half on the average. With this in mind we get for the gaseous phase ... 

A recent study combined quantum chemical calculations and electron diffrac-tion/photoelectron spectroscopy to derive the following dialkylzinc gas phase enthalpies of formation ethyl, 57 8 n-propyl, 10 8 isopropyl, 32 8 f-butyl, —17 8 neopentyl, — 117 8 kJmoF. The benchmark value of 53 1 kJmol was chosen for the gas phase enthalpy of formation of dimethylzinc. Compared to the experimental values, the diethyl and dineopentyl values are very close, but the w-propyl enthalpy of formation is just barely within the combined large error bars. The methylene increment from the theoretically derived values of diethylzinc and di-n-propylzinc is —23.5 kJ mol , a value that is consistent with other gas phase homologous series. Using this increment, the enthalpies of formation of gaseous di-w-butylzinc and di-n-pentylzinc are calculated to be —37 and —84 kJmoU, respectively. 

The use of phosphorus-based flame retardants in combination with other, better established, flame retardants is most effective in situations in which the combination proves synergistic. However, as yet our understanding of such synergistic effects is far from complete and more fundamental work is required in this area Work in which the gaseous and solid products of combustion, with and without the presence of flame retardants, are carefully analyzed. Such analyses can now be undertaken more readily than in the past, owing to the relatively recent development of techniques such as gas-phase FT-infrared spectroscopy and laser-pyrolysis time-of-flight mass spectrometry for the identification of volatiles, and solid-state NMR spectroscopy and x-ray photoelectron spectroscopy for the analysis of chars. 

Photoadsorbed species can act (i) as surface-hole trapping and photoelectrons can be trapped in the bulk of the solid or (ii) as surface-electron trapping and holes can react with OH surface groups and/or H2O. Both the alternatives depend on the chemical nature of the molecule to be adsorbed and on the type of the solid adsorbent. It is worth noting that in the gas-solid regime only gaseous species or lattice ions can be involved, whereas in the liquid phase also the interaction with the solvent (often H2O) should also be considered. 

Slaughter A, Banna M (1988) Core-photoelectron binding-energies of gaseous glycine—correlation with its proton affinity and gas-phase acidity. J Phys Chem 92 2165-2167... 

Recent developments for generating gas-phase samples from involatile chemicals have increased applications for those structural techniques that require samples to be presented in gaseous form. Techniques for generating gaseous molecular ions from the condensed phase have had massive impacts in the fields of mass spectrometry and photoelectron spectroscopy. We discuss a number of different ionization techniques in Section 11.2.1, but for now comment on the particular success of electrospray... 

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