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The formation of ternary complexes between lanthanide ions [Nd(III) or Eu(III)], octyl(phenyl)-N,N-diisobutyl-carbamoylmethylphosphine oxide (CMPO), and bis-(2-ethylhexyl)phosphoric acid (HDEHP) was probed by liquid–liquid extraction and spectroscopic techniques. Equilibrium modeling of data for the extraction of Nd(III) or Eu(III) from lactic acid media into n-dodecane solutions of CMPO and HDEHP indicates the predominant extracted species are of the type [Ln(AHA)2(A)] and [Ln(CMPO)(AHA)2(A)], where Ln = Nd or Eu and A represents the DEHP− anion. FTIR (for both Eu and Nd) and visible spectrophotometry (in the case of Nd) indicate the formation of the [Ln(CMPO)(A)3] complexes when CMPO is added to n-dodecane solutions of the LnA3 compounds. Both techniques indicate a stronger propensity of CMPO to complex Nd(III) versus Eu(III).

In this work, we have investigated new materials for potential use in automated radiochemical separations. The work can be divided into three primary tasks: (1) synthesis of new ligands with high affinity for actinide ions, (2) evaluation of new materials for actinide ion affinity, and (3) computational design of advanced ligand architectures for highly selective binding of actinide ions. Ligand Synthesis Work was conducted on synthesizing Kl?ui ligand derivatives containing functionalized pendant groups on the cyclopentadienyl ring. The functionalized pendent groups would allow these ligands to be attached to organic and inorganic solid supports. This work focused on synthesizing the compound Na[Cp?Co(PO(OC2H5)2)3], where Cp?= C5H4C(O)OCH3. Synthesizing this compound is feasible, but the method used in FY 2006 produced an impure material. A modified synthetic scheme has been developed and will be pursued in FY 2007. Work was also initiated on synthesizing bicyclic diamides functionalized for binding to polymeric resins or other surfaces. Researchers at the University of Oregon are collaborators in this work. To date, this effort has focused on synthesizing and characterizing a symmetrically substituted bicyclic diamide ligand with the ?COOH functionality. Again, this synthetic effort will continue into FY 2007. Separations Material Evaluation Work was conducted in FY 2006 to provide a more extensive set of data on the selectivity and affinity of extraction chromatography resins prepared by sorption of Kl?ui ligand onto an inert macroreticular polymeric support. Consistent with previous observations, it was found that these materials strongly bind tetravalent actinides. These materials also adsorb trivalent actinides at low nitric acid concentrations, but the affinity for the trivalent actinides decreases with increasing nitric acid concentration. These materials have relatively low affinity for U(VI), but they do sorb U(VI) to a greater extent than Am(III) at [HNO3] > 0.3 M. Preliminary results suggest that the Kl?ui resins can separate Pu(IV) from sample solutions containing high concentrations of competing ions. Conceptual protocols for recovery of the Pu from the resin for subsequent analysis have been proposed, but further work is needed to perfect these techniques. Work on this subject will be continued in FY 2007. Automated laboratory equipment (in conjunction with Task 3 of the NA-22 Automation Project) will be used in FY 2007 to improve the efficiency of these experiments. The sorption of actinide ions on self-assembled monolayer on mesoporous supports materials containing diphosphonate groups was also investigated. These materials also showed a very high affinity for tetravalent actinides, and they also sorbed U(VI) fairly strongly. Computational Ligand Design An extended MM3 molecular mechanics model was developed for calculating the structures of Kl?ui ligand complexes. This laid the groundwork necessary to perform the computer-aided design of bis-Kl?ui architectures tailored for Pu(IV) complexation. Calculated structures of the Kl?ui ligand complexes [Pu(Kl?ui)2(OH2)2]2+ and [Fe(Kl?ui)2]+ indicate a ''bent'' sandwich arrangement of the Kl?ui ligands in the Pu(IV) complex, whereas the Fe(III) complex prefers a ''linear'' octahedral arrangement of the two Kl?ui ligands. This offers the possibility that two Kl?ui ligands can be tethered together to form a material with very high binding affinity for Pu(IV) over Fe(III). The next step in the design process is to use de novo molecule building software (HostDesigner) to identify potential candidate architectures.

Les complexes M(OAr') 2 (CH 2 Ph) 2 (OAr'=di-t-butyl-2,6 phenolate; M=Ti, Zr) subissent la perte d'un equivalent de toluene par pyrolyse douce et il se forme un complexe M(OC 6 H 3 t BuCMe 2 CH 2 )(OAr')(CH 2 Ph) dans lequel une des liaisons CH d'un groupe t-butyl a ete activee et clivee. Etude cristallographique du compose Ti(OC 6 H 3 t BuCMe 2 CH 2 )(OAr')(CH 2 SiMe 3 )(pyridine) montrant la presence d'un metallocycle a six chainons

The authors wish to report here a combination of synthetic, spectroscopic, and structural studies on a number of early transition metal aryl oxide compounds containing eta/sup 2/-iminoacyl ligands. This work has allowed us to isolate and study compounds containing more than one eta/sup 2/-iminoacyl function, a situation as yet unknown for their eta/sup 2/-acyl counterparts. Compounds such as these are of importance as they may give insights into the pathways whereby the observed intramolecular coupling (carbon-carbon double bond formation) of these types of ligand can take place to produce ene-diolate, enamidolate, or ene-diamide functional groups.

Etude particuliere de Ti(OAr-iPr 2 ) 4 qui subit une reduction reversible a 1 electron dans THF, en anion Ti(OAr-iPr 2 ) 4 . Etude RX du compose neutre

During their studies of the early d-block metal chemistry associated with aryloxide ligation they have examined the reactivity of a series of mixed alkyl, aryloxide compounds toward CO and the isoelectronic organic isocyanide molecule. This has allowed them to isolate and study in detail a series of compounds containing a number of eta/sup 2/-iminoacyl functions. Furthermore they have demonstrated that intramolecular coupling of iminoacyl groups to produce enediamido ligands can take place, as well as the related coupling of iminoacyl and acyl groups. They report here in detail the synthesis of a number of enamidolate and enediamido complexes using this synthetic method and also report in detail on the coordination properties of the resulting metallacycles, an area that has received recent theoretical interest. In a subsequent paper they report a kinetic investigation of these carbon-carbon bond-forming processes.

Etude RX de Zr(OAr')(CH 2 Ph) 3 , Zr(OAr')(CH 2 PhF) 3 et de Zr(OAr')(OAr'-OMe)(CH 2 Ph) 2 , ou OAr'=di-t-butyl-2,6 phenol et OAr'-OMe=methoxy-4 di-t-butyl-2,6 phenol. Cristallisation respectivement dans C2/c avec Z=8 (R=0,0628), P2 1 /n avec Z=4 (R=0,0658) et P2 1 /c avec Z=4 (R=0,0410). Etude RMN ( 1 H et 13 C)

Carbon monoxide dissociates to reactive carbide and oxide fragments on many catalytically active metal surfaces. Dissociation is believed to be the first step in the reductive hydrogenation of CO via the Fischer-Tropsch synthesis and related reactions. The remarkable reactivity of these surface carbides is probably due to the fact that they are highly exposed, with a low coordination number. Most organometallic carbide complexes contain carbon atoms surrounded by at least five metal atoms. However, (Fe/sub 4/C(CO)/sub 12/)/sup 2 -/ and related tetranuclear carbide clusters studied by Bradley, Muetterties, and Shriver show high reactivity at the carbide ligand. The chemistry of (Fe/sub 3/(CCO)(CO)/sub 9/)/sup 2 -/ suggests the intermediacy of a very reactive Fe/sub 3/C cluster. The sole fully characterized example of a two-coordinate metal carbide complex is (Fe/sub 2/(..mu../sub 2/-C)(5,10,15,20-tetraphenylporphyrinate)/sub 2/). A dinuclear bicarbide complex, (Ta/sub 2/(..mu../sub 2/-C/sub 2/)/OSi(CMe/sub 3/)/sub 3///sub 6/), has recently been reported by Wolczanski and co-workers. They report here the first heterodinuclear complex with a two-coordinate carbide ligand, ((Me/sub 3/CO)/sub 3/W identical to C-Ru(CO)/sub 2/(Cp)).

Etude particuliere de Ti(OAr-iPr 2 ) 4 qui subit une reduction reversible a 1 electron dans THF, en anion Ti(OAr-iPr 2 ) 4 . Etude RX du compose neutre