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  • Author: W. H. Koppenol x
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Introduction: Knowledge of the properties and reactivities of stable inorganic radicals was obtained decades ago through gas-phase studies of various oxides of halogens, sulfur, and nitrogen. More recently, pulse radiolysis and flash photolysis techniques developed in the 1960s made it possible to study short-lived radicals, such as hydrated electrons, hydrogen atoms, and hydroxyl radicals. Because of the high time-resolution of these techniques, absorption spectra and redox properties of these inorganic radicals could be determined. The interest in radicals increased when it was shown that superoxide, or dioxide(1-), is formed in vivo. The discovery that in aerobic organisms enzymes catalyze the disproportionation of this radical resulted in new areas of research, such as radical biology and radicals in medicine. Interest in simple radicals was further boosted most recently by the remarkable observation that the radical nitrogen monoxide is formed enzymatically from the amino acid arginine. Radicals are important in a variety of catalytic processes and in the atmospheric gas and liquid phases; furthermore, a substantial number of inorganic radicals have been observed in interstellar gas clouds.

Contents:

1. Introduction

2. Definitions

3. Nomenclature

A procedure is proposed to name new elements. After the discovery of a new element is established by a joint IUPAC­IUPAP Working Group, the discoverers are invited to propose a name and a symbol to the IUPAC Inorganic Chemistry Division. Elements can be named after a mythological concept, a mineral, a place or country, a property, or a scientist. After examination and acceptance by the Inorganic Chemistry Division, the proposal follows the accepted IUPAC procedure and is then submitted to the IUPAC Council for approval.

Muons are short-lived species with an elementary positive or negative charge and a mass 207 times that of the electron. These recommendations concern positive muons, given the short lifetime of negative muons. A positive muon mimics a light hydrogen nucleus, and names are given in analogy to existing names for hydrogen-containing compounds. A particle consisting of a positive muon and an electron (µ+ e -) is named "muonium" and has the symbol Mu. Examples: "muonium chloride," MuCl, is the equivalent of deuterium chloride, 2 HCl or DCl; "muoniomethane", CH 3 Mu, is the product of the muoniation of methane;and NaMu is "sodium muonide."