The Electronic Structure of Superhalogens and Superalkalies

Molecular systems with anomalous values of the first ionisation ptoentials or electron affinity have been examined. On the basis of the results of calculations by the DV-X_α method it has been possible to relate the values of the electron affinity and the first ionisation potential to the characteristic features of the electronic structure of these compounds. The analysis carried out has made it possible to distinguish two large classes of chemical compound: with an anomalously high electron affinity (superhalogens) and with anomalously low first ionisation potentials (superalkalies). Estimates of the maximum possible electron affinity of chemical compounds have been given, and ways of finding these systems have been outlined. Various possible manifestations of high electron affinity and low first ionisation potentials in the physicochemical properties of superhalogens and superalkalies have been examined. The bibliography contains 133 references.