Abstract
Selenium forms a very large number of inorganic and organic compounds showing different reactivity and structural properties. Among them there are hypervalent compounds, selenuranes - the derivatives in which the central selenium atom has expanded its valence shell from 8 to 10 or 12 electrons. Such compounds are presented in the chapter using the criterion of classification which is based on the formal oxidation state and number (N) of ligands bonded to selenium. For each class, the methods of synthesis, complemented with the mechanistic and stereochemical studies, are comprehensively discussed.
Keywords: Hypervalent Selenium, Hypervalent Bonding, Selenium Trihalides, Selenuranes, Selenurane Oxides, Perselenuranes, Spiroselenuranes, Dihaloselenuranes, Bicyclic selenuranes, Chirality.