Neptunium, plutonium and americium heptavalent state

The monography reviews evidence on chemistry of heptavalent state of transuranic compounds up to 1976. Methods of synthesis, stability, chemical and physical properties of heptavalent neptunium, plutonium and americium in solutions and melts are described, as well as methods of obtaining their compounds and analytical determination. Out of the new redoxreactions resulting in the heptavalent state of these elements, particularly important are the disproportioning of Np(6) and Am(6). Differences between properties of the heptavalent states have been studied. It is pointed out that preparative chemistry of heptavalent actinoids is a poorly studied field, particularly in case of americium. Directions of further investigations on heptavalent transuranides are indicated