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Electron ionization. Electron ionization (EI, formerly known as electron impact ionization [1] and electron bombardment ionization [2]) is an ionization method in which energetic electrons interact with solid or gas phase atoms or molecules to produce ions. [3] EI was one of the first ionization techniques developed for mass spectrometry. [4]
The electron binding energy derives from the electromagnetic interaction of the electron with the nucleus and the other electrons of the atom, molecule or solid and is mediated by photons. Among the chemical elements, the range of ionization energies is from 3.8939 eV for the outermost electron in an atom of caesium to 11.567617 keV for the ...
On the one hand, the ionization energy (also called ionization potential, IP), refers to the energy necessary to remove one electron from a molecule; the lowest IP, corresponding to the ejection of a first electron, is the most biologically relevant factor. On the other hand, the photoionization quantum yield Φ, that is the number of electrons ...
The original ionization event in these instruments results in the formation of an "ion pair"; a positive ion and a free electron, by ion impact by the radiation on the gas molecules. The ionization chamber is the simplest of these detectors, and collects all the charges created by direct ionization within the gas through the application of an ...
Adiabatic ionization is a form of ionization in which an electron is removed from or added to an atom or molecule in its lowest energy state to form an ion in its lowest energy state. [ 16 ] The Townsend discharge is a good example of the creation of positive ions and free electrons due to ion impact.
The electron donating power of a donor molecule is measured by its ionization potential, which is the energy required to remove an electron from the highest occupied molecular orbital . The overall energy balance (ΔE), i.e., energy gained or lost, in an electron donor-acceptor transfer is determined by the difference between the acceptor's ...
[1] This is the minimum electron energy that produces an ion. [2] In photoionization , it is the minimum photon energy of a photon that produces some ion signal. For example, the indene bromide ion (IndBr+) only loses bromine at an incident photon energy of 10.2 eV, so the product, indenyl, has an appearance energy of 10.2 eV.
Electron capture ionization (ECI) is the ionization of a gas phase atom or molecule by attachment of an electron to create an ion of the form A −•.The reaction is + where the M over the arrow denotes that to conserve energy and momentum a third body is required (the molecularity of the reaction is three).