Crystal and molecular structure of hydridotris[bis(trimethylsilyl)amido]uranium(IV)

Mixed‐Donor Amido–Siloxo Actinide(IV) Halide and Alkyl Complexes with an Aryl Cipso Interaction

“…The U1–N10 bond length of 2.273(3) Å in 5 (Table 4) is slightly longer than the U–N bond lengths in 3 but still compares well with those in {[NON]UCl 2 } 2 and other monodentate amido uranium complexes 36,61,62. The U1–O10 bond length of 2.105(3) Å in 5 is slightly shorter than that in 3 , consistent with a terminal bond rather than a bridging bond.…”

“…The U1–N10 bond length of 2.229(17) Å in 3 (Table 3) is unremarkable and compares well with the U–N bond lengths in {[NON]UCl 2 } 2 [2.224(8) and 2.223(8) Å]36 and {[SiMe 3 N(CH 2 CH 2 NSiMe 3 ) 2 ]UCl 2 } 2 [2.194(3) and 2.215(4) Å] 39. This bond length also compares reasonably well with those of monodentate amido uranium complexes such as UH[N(SiMe 3 ) 2 ] 3 [U–N 2.237(9) Å]61 and U[N(SiMe 3 ) 2 ] 2 Cl 2 · DME [U–N 2.231(8) and 2.238(7) Å] 62. The U1–O10 bond length of 2.147(13) Å is considerably shorter than those of the bridging tert ‐butoxide ligands in {U[OSi(O t Bu) 3 ] 2 [μ‐OSi(O t Bu) 3 ]} [ave. U–O 2.396(3) Å]31 or the bridging isopropoxide ligands in {[ t Bu NON]U(O i Pr) 2 } 2 [U–O 2.326(17) Å];43 instead, the U–O bond length in 3 is more comparable to the terminal U–O bond lengths in both of these compounds [{U[OSi(O t Bu) 3 ] 2 [μ‐OSi(O t Bu) 3 ]}, average 2.193(4) Å] 31.…”

Phenylsilane as a safe, versatile alternative to hydrogen for the synthesis of actinide hydrides

“…Compared to the hundreds of reported transition metal and lanthanide hydrides, there are only a limited number of thorium and uranium hydride complexes. [1][2][3][4][5][6][7][8][9][10][11][12][13][14] The bis(pentamethylcyclopentadienyl) complexes [(C 5 Me 5 ) 2 An(H)(m-H)] 2 (An = Th (1), U (2)) were the first isolable organoactinide hydride complexes; 12 and since their introduction in 1982, they have displayed a palette of chemical reactivity such as the stoichiometric and catalytic hydrogenation of unsaturated substrates, 9,12,[15][16][17] the catalytic dimerization of propylene, 18,19 coupling reactions, [20][21][22] and multi-electron reductions (following liberation of H 2 ). 13,14,[23][24][25] The chemistry of actinide hydrides is still not well understood.…”

Die Renaissance der nichtwässrigen Uranchemie

“…Wie bei den Alkylderivaten überwiegen bei den Amiden heteroleptische Varianten, nur wenige homoleptische Komplexe sind bekannt. Eines der am häufigsten eingesetzten homoleptischen Amide ist der 1981 beschriebene Uran(III)‐Komplex [U{N(SiMe 3 ) 2 } 3 ] ( 75 ),125a,b der leicht aus 3THF und drei Äquivalenten Natrium‐ oder Kalium‐bis(trimethylsilyl)amid synthetisiert und durch Sublimieren oder sorgfältiges Umkristallisieren aufgereinigt werden kann (Abbildung 18). Die niedrige formale Koordinationszahl von 3 in 75 und substituierten Varianten125c ist möglicherweise für Reaktivitätsstudien wertvoll, und bisher konnten die Aktivierung etlicher kleiner Moleküle, die Bildung neuer Ligandenverknüpfungen und die Oxidation zu Uran(V)‐Derivaten126 sowie auch das SMM‐Verhalten (Abschnitt 5.1) untersucht werden.…”