Abstract
Tri-ethyl-ammonium hexa-bromido-uranate(IV) di-chloro-methane monosolvate, [(C2H5)3NH]2[UBr6]·CH2Cl2, was obtained in the form of dark-brown crystals from the reaction of uranium penta-bromide with NEt3 and ethyl-ene glycol in di-chloro-methane at low temperature. During the progress of the reaction, the reduction of uranium(V) to uranium(IV) was observed, whose associated oxidation product could not be identified. The uranium atom of the [UBr6]2- anion is coordinated by six bromido ligands in the shape of an octa-hedron. Between cations, anion and solvent mol-ecules of crystallization, numerous C-H⋯Hal hydrogen-bond-like inter-actions are present, leading to a three-dimensional network structure.
Highlights
Triethylammonium hexabromidouranate(IV) dichloromethane monosolvate, [(C2H5)3NH]2[UBr6]ÁCH2Cl2, was obtained in the form of dark-brown crystals from the reaction of uranium pentabromide with NEt3 and ethylene glycol in dichloromethane at low temperature
The uranium atom of the [UBr6]2– anion is coordinated by six bromido ligands in the shape of an octahedron
The only two structurally elucidated examples of hexabromidouranate(V) anions, [UBr6]À, that show significantly shorter U—Br distances compared to [UBr6]2– anions are (Ph4P)[UBr6] and (Ph4P)[UBr6]Á2CCl4 (Bohrer et al, 1988). These two compounds as well as (PPh4)[UBr6]ÁCH2Cl2 serve as examples for the stability of uranium(V) in organic solvents; a reduction of UV to UIV was observed upon removal of the solvent (Bohrer et al, 1988)
Summary
Starting in the 1950s, a variety of hexachloridouranates(IV) with organic cations have been investigated and described [CSD Database, Version 2.0.4, accessed 19.05.2020 (Groom et al, 2016); Staritzky & Singer, 1952). The only two structurally elucidated examples of hexabromidouranate(V) anions, [UBr6]À, that show significantly shorter U—Br distances compared to [UBr6]2– anions are (Ph4P)[UBr6] and (Ph4P)[UBr6]Á2CCl4 (Bohrer et al, 1988) These two compounds as well as (PPh4)[UBr6]ÁCH2Cl2 serve as examples for the stability of uranium(V) in organic solvents; a reduction of UV to UIV was observed upon removal of the solvent (Bohrer et al, 1988). During this reaction, elemental bromine was formed via oxidation besides the adduct UBr4ÁCH3CN (Bohrer et al, 1988).
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Acta crystallographica. Section E, Crystallographic communications
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
