Physical and Chemical Properties of Dissolved Electrons (Excess Electrons)

Abstract

Electrons produced in a gaseous, liquid, or solid solvent are called dissolved electrons or excess electrons. These excess electrons can exist as quasi-free particles of high mobility in a delocalized state, comparable with electrons in a metal; or as bound particles of low mobility they can be localized within narrow limits-in a solvent cavity formed by repulsive forces. Localized electrons can also be solvated like normal ions. Characteristically, such solvated electrons exhibit broad and extensive absorption spectra in the visible to near infrared spectral range. The localized and delocalized states of the excess electrons can be in equilibrium with each other, such that a continuous transition of the properties between the limiting extremes can be observed. The reactions of the excess electrons with suitable acceptors (substrates) are initiated by an attachment-detachment equilibrium A +e-*Awhich is followed by further chemical rearrangements. The rate constants of these reactions vary by more than 15 powers of ten depending on the substrates and the solvents. Most of the properties of excess electrons in solution can be interpreted by means of a model which is easily understandable but quantitatively evaluated only with considerable effort.

Electron Tunneling in Lithium–Ammonia Solutions Probed by Frequency-Dependent Electron Spin Relaxation Studies

“…In addition, the well-formed structure out of which the electron tunnels is to another, less-formed structure of somewhat higher energy. 10,60,61 …”

Revisiting Bragg's X-ray microscope: Scatter based optical transient grating detection of pulsed ionising radiation

“…Many materials can accommodate higher F-centre densities [4,5,116]. Chemical manipulation of liquids and glasses provides latency spanning at least fifteen orders of magnitude in time [35], opening prospects for either transient or integrating usage, depending on experimental needs. For optical interrogation, the synchronicity, brevity, monochromaticity and power of Nd-YAG lasers popularly used to pump regenerative Ti:sapphire lasers is potentially useful, bearing in mind many contemporary approaches using the latter systems for generating short-wavelength radiation bursts.…”

“…This work places greater emphasis on transient modalities, whose scope in contemporary studies [32] is clear. The vast ranges of timescales relevant to items 3 and 4, and obtainable in even just one example detection medium (water) [33][34][35][36], fully encompass those in conventional detectors such as charge-coupled devices (CCDs), complementary metal oxide silicon (CMOS) and more recent serial time encoded imaging technologies [37], any of which could be used for eventual optical detection in this work.…”

Sodium Amide

“…has a much lower density than liquid ammonia and hence a higher volume than would be expected from the sum of the volumes of the metal and the solvent, concepts of the structure of such solutions have been developed [2], [3], [11], [12]. The increase in the apparent molar volume must be due to the unusual state of solution of the electrons, since volume increases of this order are not observed for solutions of other substances.…”

“…The observed physical and chemical properties of solutions of alkali metals in liquid ammonia have not yet been explained by a single model [11], [13], [16].…”