Crystal Structure of Regularly T -Symmetric [U(NO ) ] Salts with Hydrogen Bond Polymers of Diamide Building Blocks.

Hexanitratouranate(IV), [U(NO ) ] , has been crystallized with anhydrous H -involving hydrogen bond polymers connected by selected diamide building blocks. Thanks to the significant moderation of electrostatic interactions between the anions and cations, the molecular structure of [U(NO ) ] in these compounds is regularly T -symmetric. The f-f transitions stemming from 5f configuration of U are 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 species usually coloured in green.