Publikationsrepositorium - Helmholtz-Zentrum Dresden-Rossendorf

Hexanitratouranate(IV), [U(NO₃)₆]²⁻, has been crystallized with anhydrous H⁺ counter cations stabilized by formation of hydrogen bond polymers with selected diamide building blocks. Thanks to the significant moderation of electrostatic interactions between the anions and cations, the molecular structure of [U(NO₃)₆]²⁻ in these compounds is regularly Th-symmetric. The f-f transitions stemming from 5f² configuration of U⁴⁺ is strictly forbidden by the Laporte selection rule in such a centrosymmetric system , so that the obtained compounds are nearly colourless in contrast to other U(IV) species usually coloured in green.