A Dinuclear Uranium Complex [{UO₂F₂(NH₃)}₂(μ‐F)₂]²⁻ from Reaction of TlF and UO₂F₂ in Liquid Anhydrous Ammonia and Fluoride Ion Affinities for Some Uranyl(VI) Species [UO₂F_x]^2−x and [UO₂F_x(NH₃)_5−x]^2−x

Abstract

UO2F2 abstracts F− anions from TlF in liquid ammonia solution and the compound [Tl2(NH3)6][{UO2F2(NH3)}2(μ‐F)2] is formed. The compound has been characterized by single crystal X‐ray diffraction, Raman spectroscopy and quantum‐chemical calculations for the solid state. Quantum‐chemical investigation of the [{UO2F2(NH3)}2(μ‐F)2]2− anion showed that the U−(μ‐F)−U σ‐3c‐4e‐bond is essentially ionic. The [Tl2(NH3)6]2+ cation shows a thallophilic Tl⋅⋅⋅Tl interaction. Fluoride ion affinities (FIAs) were calculated for different UO22+ species [UO2Fx]2−x and [UO2Fx(NH3)5−x]2−x with x=0 to 4.