Аннотации:
Data are presented on the methods of synthesis, structure, and physical and chemical properties of cyclic compounds of hexacoordinate phosphorus–Λ6-1, 3, 2-diheterophosphacyclanes, in which the phosphorus atom is incorporated in one, two, and three heterocycles containing P–O or P–N bonds. The dynamic stereochemistry and equilibrium dissociative as well as tautomeric processes involving them are described. The role of phosphorus(VI) intermediates in the reactions of organophosphorus compounds with tricoordinate, tetracoordinate, and pentacoordinate phosphorus is analysed. The bibliography includes 140 references. © 1987 IOP Pubilishing Ltd.