Uranium imido

Cramer, Panchanatheswaran, and Gilje [37] have also reported that the CP3UCHPR3 compounds undergo insertion reactions with acetonitrile to yield uranium imido complexes (eq.(23)). Diffraction studies... 

The reaction of (CH3C5H4)3U THF with organic azides and with organic isocyanides yields uranium imido (equation (22.17)) and isocyanato (equation (22.18)) complexes [32] ... 

The CP3UCHPR3 complexes also undergo insertion into the CsN bonds of nitriles and the C s O bonds of metal carbonyls. Thus, Cramer et al. [39] reported that insertion reactions with acetonitrile yield uranium imido complexes ... 

In the second example we present a study where theoretical helped unravel an unexpected result in the laboratory a reaction expected to lead to the thermodynamically most stable species (uranium oxo), instead generated a uranium imido species. As mentioned earlier, the uranyl ion possesses U-O bonds with high thermodynamic stability and extreme kinetic inertness. As a result, the majority of uranyl ion reaction chemistry involves substitution of equatorially coordinated ligands while leaving the U-O bond unaffected. Its isoelectronic bis(imido) [U(NR)2] + analog, while possessing many of the bonding features found in UO2+ [46] exhibits reactivity quite distinct from UO. ... 

Bishomoallyl alcohols, via allyindium reagents, 9, 703 Bis(hydrostannation), in tin-carbon bond formation, 3, 814 Bis(imidazolyl) ligands, chromium complexes, 5, 359 Bis(imido) systems, with chromium(VI), as models, 5, 377 Bis(imido)tungsten complexes, synthesis, 5, 749 Bis(imido)uranium(VI) complexes, synthesis, 4, 216-217 Bis(imino)carbenes, with Zr(IV), 4, 798 Bis(iminooxazolidine) complexes, biaryl-bridged, with Zr(IV) and Hf(IV), 4, 811-812... 

The bis-MeCsELi or bis-Cp framework is a useful template for organoimido and organophosphinidene complexes. Comproportionation of uranium(III) and ura-nium(V) metallocenes provides a route to dinuclear ura-nium(IV) imido complexes (equation 11). The molecular structure of [(MeC5H4)2U(NPh)]2 is depicted in (5). 

The uranium(IV) imido complex Cp 2U(=N-2,4,6-t-BU3C6H2) also reacts with diphenyldiazomethane to give the uranium(VI) mixed bis-imido complex Cp 2U(=N-2,4,6-t-Bu3C6H2)(=N-N=CPh2)." " The latter compound does... 

Bums and coworkers have discovered a remarkable reaction involving Cp 2U(Me)Cl. Treatment of the latter with l-lithio-l,2-diphenylhydrazine in ether solution generates lithium chloride and methane, and provides the uranium(VI) bis-imido compound Cp 2U(NPh)2, conceivably via a uranium(lV) hydrazido species Cp 2U( ] -PhNNPh)." A plausible reaction sequence is laid out in equations (61) and (62). Cp 2U(NPh)2 was the first uranium(Vl) organometallic complex. In the solid state, Cp 2U(NPli)2 adopts the famihar... 

The synthesis of the bis(imido)uranium(vi) complexes Cp 2U(NR)2 (R = Ph, 1-adamantyl (1-Ad)) was achieved according to Scheme 55 in a one-pot reaction with high yield. In this reaction the N=N double bond is cleaved by the uranium metal center. This is only possible if the /-orbital is involved in the cleavage of the double bond. For the /-transition metals such a cleavage is symmetry forbidden. a Yet another preparation of the... 

Thermolysis of Cp 2U(=NAd)2 in benzene or hexane resulted in the intramolecular G-H bond activation of a methyl group on a pentamethylcyclopentadienyl ligand across the imido functional groups.123 The activation product is a reduced U(iv) metallocene bis(amide) complex with an A-bonded methylene unit derived from the methyl group attached to one amide group. Scheme 56 shows the formation of the ring bite uranium complex with the two possible structures that are consistent with the XH NMR data.123... 

Other bis(imido) organouranium (VI) complexes have been prepared, and for a metallocene complex, a general pathway is represented in Scheme 2. The reactions involve the oxidation of uranium (IV) bis-alkyl or uranium (IV) imido complexes... 

A very elegant and simple procedure for the generation of high-valent bis(imido) organouranium (VI) complexes 13, and 15 was described starting from the organo-metallic uranium (111) complex 16. The reaction involves the direct reduction of diazenes or azides (6) [54]. 

Working on this series of compounds, Cramer et aL reported [234] a complex which contains an uranium-nitrogen midtiple bond, i.e., an (imido)uranium complex (C5H5)3UNC(CH3)CHP(C6H5)2CH3 (Eq. 42) ... 

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