Organometallic uranium

Bilinear chemometrics methods, 6 39-57 Billet products, titanium, 24 858 Bill of Material, 15 460, 470 Bills of lading, 25 330 Bimetal complexes, 16 88 Bimetallic deactivation processes, 16 93-94 Bimetallic fluorides, 15 396 Bimetallic metal nitrides, 17 199 Bimetallic organometallic uranium complexes, 25 442 Bimetallic organometallic thorium complexes, 24 773-774... 

U(OCH3)F5. We have also investigated methoxy derivatives of UF6. In Table IV, we present calculated and experimental (43) absolute shieldings for U(OCH3)F5 that has been chosen as a representative example. So far, scalar and spin-orbit Pauli (QR) calculations have been performed for this organometallic uranium (VI) system. 

As an illustrative example taken from the current literature, consider the variation of C-C and C-O bond lengths in the deltate species CsO2- held within a dinuclear organometallic uranium(IV) complex. In a remarkable synthesis, this cyclic aromatic oxocarbon dianion is generated by the metal-mediated reductive cyclotrimerization of carbon monoxide, as indicated in the reaction scheme... 

The preparation and structure determination of ferrocene marked the beginning of metallocene chemistry Metallocenes are organometallic compounds that bear cyclo pentadiemde ligands A large number are known even some m which uranium is the metal Metallocenes are not only stucturally interesting but many of them have useful applications as catalysts for industrial processes Zirconium based metallocenes for example are the most widely used catalysts for Ziegler-Natta polymerization of alkenes We 11 have more to say about them m Section 14 15... 

Many substituted uranocenes have been made and there is a substantial body of organometallic chemistry of uranocene derivatives now known 16, 17). Some of this chemistry will be mentioned in passing but wiU not be covered in a systematic way since other reviews of the organic chemistry are available 18). The only other actinide cyclooctatetraene complex structurally characterized to date is bis[(l,3,5,7-tetramethylcyclooctatetraenyl]uranium(IV) 19), which was of interest because the presence of methyl groups allowed the planarity and relative orientation of the dianion rings to be determined. Crystal and molecular parameters for these three actinide compounds are summarized in Table 1. 

The surface organometallic chemistry of thorium and uranium has been pioneered and developed by Marks et al. since the mid-1980s [3]. In contrast to... 

Ketoenolates have not been isolated for the tripositive elements in the attempted preparation of Pu(MeCOCHCOMe)3, oxidation to plutonium(IV) occurred very readily.17 Complexes with ethers appear to be restricted to THF solvates apart from UC13-THF, a useful starting material for uranium(III) preparative chemistry,18 the only other examples are solvated organometallic compounds, such as Cp3Np-3THF and Cp3PuTHF. 

A nonstandard synthesis of the first uranium cluster containing an isopolyoxo-metalate core was reported recently [310b], Reduction of [Cp UCl2] (Cp7 — 1,2,4-/-Bu3C5H2) with two equivalents of KC8 in THF, followed by an addition of two equivalents of pyridine N-oxide, was conducted in an attempt to produce the organometallic dioxo species [Cp7U02]. However, the cluster compound [Cp (bipy)2][U6013] was isolated instead as the main product (54% yield) from this reaction. 

During the Manhattan project, a wide range of compounds was screened in the search for volatile uranium compounds that could be used for separation of isotopes of uranium, since UFe was not an easy compound to handle. The leading organometallic chemist of the day, Henry Gilman, investigated the synthesis of simple alkyls and aryls, concluding that such compounds did not exist, or at least were unstable. Even today, just one neutral homoleptic... 

High oxidation states are not normally associated with organometallic chemistry, but a remarkable uranium(vi) imide has been made (Figure 13.1) ... 

Not every actinide element has known or well-developed organometallic chemistry. By far the most research has been done on thorium and uranium compounds, a consequence of favorable isotope-specific nuclear properties and, at least until recently, the commercial availability of key starting materials such as Th metal, anhydrous ThCLi, U metal, and anhydrous UCL. Thorium chemistry is dominated by the -F4 oxidation state and has some similarities to the chemistry of the heavier group 4 metals. For uranium, one can access oxidation states from d-3 to 4-6 in organic media. Although there are some similarities to the chemistry of the heavier group 6 elements, for example, tungsten, there are also some remarkable differences made possible by the availability of the 5f valence orbitals. 

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... 

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