Oxidation of uranium(iv) thiocyanate complexes: cation-cation interactions in mixed-valent uranium coordination chains

Oxidation of Cs-4[U(NCS)(8)] in MeCN or DMF affords structurally characterised examples of the mixed-valent U-IV/VI compound Cs-14[{U(NCS)(8)}(3){UO2(NCS)(4)(H2O)}]4.5H(2)O, or the [U-IV-U-V-U-IV][U-VI] species [U(DMF)(8)(-O)U(NCS)(5)(-O)U(DMF)(7)(NCS)][UO2(NCS)(5)]. Vibrational and magnetism data support their oxidation state formulism, which is further corroborated by computational methodology.