Electron Capture

Broad in scope, this book describes the general theory and practice of using the Electron Capture Detector (ECD) to study reactions of thermal electrons with molecules. It reviews electron affinities and thermodynamic and kinetic parameters of atoms, small molecules, and large organic molecules obtained by using various methods. * Summarizes other methods for studying reactions of thermal electrons with molecules * Discusses applications in analytical chemistry, physical chemistry, and biochemistry * Provides a data table of electron affinities

The total Oppenheimer-Brinkman-Kramers (OBK) cross sections for 1s-, 2s-, and 2p-orbital electron capture from atomic nitrogen by protons are adjusted to correspond to capture from N2 by deuterons, and are compared with recent measurements of Berkner et al. Calculated cross sections for 1s capture are dominant above 3 MeV, and the total OBK cross section still exceeds the measured cross section at the deuteron energy of 21.5 MeV.

Classical and quantal nonrelativistic scattering between simple atomic systems is reviewed, and most approximations currently used in calculations on electron capture are discussed. The OBK interaction is generalized to include capture from neutral atoms by singly charged many-electron ions; the sum over the squares of the vector coupling coefficients is affected in the formula for the OBK cross section for p-orbital capture by protons into H(ns). The cross section for H(+) + H(1s) to H(Sigma n1) + H(+) at high impact energies is determined classically. The second Born amplitudes at high impact energies for H(+) + H(1s) to H(1s) + H(+) and H(+) + D(1s) to H(1s) + D(+) are evaluated approximately using the Green's function of the post Hamiltonian. Two modifications of Thomas' classical model for heavy atoms are proposed, and corresponding cross sections are calculated for H(+) + B to H(Sigma n1) + B(+) with B = O, N, Ne, A, Kr, Xe. A semiclassical theory is developed for charge transfer in alkali atom-alkali-ion collision at low impact velocities, and cross sections are obtained for H, Li, Na, K, Rb, Cs. OBK cross sections are calculated for s-orbital capture from He(1s(2)), N((4)S), O((3)P), and p-orbital capture from N((4)S), O((3)P), all for incident protons capturing into H(1s). Born prior and post cross sections are calculated for H(+) + O((3)P) to H(1s) + O(+)((4)S) and H(1s) + H(1s) to H( - )(1s(2)) + H(+).

The only comprehensive guide to CIMS applications in structural elucidation and analytical studies Chemical Ionization Mass Spectrometry, 2nd Edition, provides a comprehensive, up-to-date review of CIMS applications in structural elucidation and quantitative analytical studies. For the benefit of readers without a background in gaseous ion chemistry, a thorough review is presented in Chapter 2. Other chapters discuss such topics as reagent ion systems within the context of the thermochemistry and kinetics of the ionization process, including reactions and the type of information obtained; isotopic exchange reactions; stereochemical effects in chemical ionization; and reactive ion/molecule collisions in quadrupole cells. Chemical ionization mass spectra of 13 classes of compounds are discussed in detail to illustrate the influence of different functional groups on the spectra observed. Chemical Ionization Mass Spectrometry, 2nd Edition will be a valuable reference for anyone interested in mass spectrometry and gaseous ion chemistry in general.