The Uranium(VI) Oxoazides [UO2(N3)2⋅CH3CN], [(bipy)2(UO2)2(N3)4], [(bipy)UO2(N3)3]−, [UO2(N3)4]2−, and [(UO2)2(N3)8]4−. Issue 3 (1st December 2016)

• Record Type: Journal Article
• Authors: Haiges, Ralf; Vasiliu, Monica; Dixon, David A.; Christe, Karl O.
• Is Part Of: Chemistry. Volume 23:Issue 3(2017)
• Page Start: 652
• Page End: 664
• Publication Date: 2016-12-01
• Subjects: azides -- crystal structures -- polyazides -- uranium -- uranyl; Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201604154
• Languages: English
• ISSNs: 0947-6539

Abstract

Abstract: The reaction between [UO2 F2 ] and an excess of Me3 SiN3 in acetonitrile solution results in fluoride–azide exchange and the uranium(VI) dioxodiazide adduct [UO2 (N3 )2 ⋅CH3 CN] was isolated in quantitative yield. The subsequent reaction of [UO2 (N3 )2 ⋅CH3 CN] with 2, 2′‐bipyridine (bipy) resulted in the formation of the azido‐bridged binuclear complex [(bipy)2 (UO2 )2 (N3 )4 ]. The triazido anion [(bipy)UO2 (N3 )3 ] − was obtained by the reaction of [UO2 (N3 )2 ⋅CH3 CN] with stoichiometric amounts of bipy and the ionic azide [PPh4 ][N3 ]. The reaction of [UO2 (N3 )2 ] with two equivalents of the [PPh4 ][N3 ] resulted in the formation of the mononuclear tetraazido anion [UO2 (N3 )4 ] 2− as well as the azido‐bridged binuclear anion [(UO2 )2 (N3 )8 ] 4− . The novel uranium oxoazides were characterized by their vibrational spectra and in the case of [(bipy)2 (UO2 )2 (N3 )4 ]⋅CH3 CN, [PPh4 ][(bipy)UO2 (N3 )3 ], [PPh4 ]2 [UO2 (N3 )4 ], [PPh4 ]2 [UO2 (N3 )4 ]⋅2CH3 CN, and [PPh4 ]4 [(UO2 )2 (N3 )8 ]⋅4CH3 CN by their X‐ray crystal structures. Abstract : Energetic crystals : Several novel uranium(VI) azides were prepared and characterized. [UO2 (N3 )2 ⋅CH3 CN] was obtained by fluoride–azide exchange from [UO2 F2 ] and Me3 SiN3 . The reactions of [UO2 (N3 )2 ⋅CH3 CN] with 2, 2′‐bipyridine and [PPh4 ][N3 ] afforded [(bipy)2 (UO2 )2 (N3 )4 ], [PPh4 ][(bipy)UO2 (N3 )3 ], [PPh4 ]2 [UO2 (N3 )4 ], [PPh4 ]2 [UO2 (N3 )4 ], and [PPh4 ]4 [(UO2 )2 (N3 )8 ], which were characterized by their X‐ray crystal structures.