A concept of nephelauxetic series of systems is advanced which implies
arranging all the spectroscopically studied compounds and media for a
given S-ion (actinide or lanthanide) in the order of the nephelauxeti
c effect increase. When analysed as a whole, such a series can show tr
ends in the degree of the f-shell interaction with the environment, as
dependent on the nature of ligands and outer-sphere cations, as well
as on coordination number, medium (matrix), and temperature. It is sug
gested that hypersensitivity series of systems can be composed for an
actinide ion, which correlates with the corresponding nephelauxetic se
ries.