Fluorinated diarylamide complexes of uranium(III, IV) incorporating ancillary fluorine-to-uranium dative interactions

The fluorinated diarylamines HNPhPhF, HNPh2F, HNPhArF, Ph-F = 2,3,4,5,6- pentafluorophenyl, Ar-F = 3,5-bis(trifluoromethyl)phenyl, are used to prepare complexes of uranium(III, IV) ions. Despite being electron-poor amines with little steric bulk, their coordinated amide ligands exhibit direct control over the coordination environment through a subtle, cooperative interplay of multiple labile F -> U dative interactions and favorable arene-arene interactions. The C-F -> U interactions, similar to 8.9 kcal mol(-1) as determined by variable temperature NMR experiments, persist in solution and allow the isolation of otherwise unstable species as well as the first pseudo-square planar uranium complex.