Metal Complexes

Hay, Benjamin P.; Clement, Omoshile

doi:10.1002/0470845015.cma015

Cited by 3 publications

(2 citation statements)

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“…In part this is due to the past focus on pure organic systems, and in part, this is due to the way molecular mechanics models work-a unique set of parameters is required for each different metal ion and each different type of donor atom. When applying the molecular mechanics technique to metal-ligand complexes, one must focus on a class of metal complexes to limit the number of metal ions and donor atom types and then develop a set of parameters before performing the calculations (Hay 1993;Hay and Clement 1998a).…”

Section: Extension Of Mm3 To Treat Kläui Ligands and Their Metal Compmentioning

confidence: 99%

Selective Media for Actinide Collection and Pre-Concentration: Results of FY 2006 Studies

Lumetta¹,

Addleman²,

Hay³

et al. 2006

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SummaryIn 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 SynthesisWork was conducted on synthesizing Kläui 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(OC 2 H 5 ) 2 } 3 ], where Cp′= C 5 H 4 C(O)OCH 3 . 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 EvaluationWork 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 Kläui 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 [HNO 3 ] > 0.3 M. Preliminary results suggest that the Kläui 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.

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Section: Extension Of Mm3 To Treat Kläui Ligands and Their Metal Compmentioning

confidence: 99%

Selective Media for Actinide Collection and Pre-Concentration: Results of FY 2006 Studies

Lumetta¹,

Addleman²,

Hay³

et al. 2006

Self Cite

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“…Whilst empirical molecular mechanics [5] and semiempirical methods [6] have found utility in calculations on transition-metal complexes, the requirement for suitable parametrisation has limited their use. More common are ab initio techniques, in particular Hartree-Fock (HF) methods, which can provide reasonable results for second and third row transition metals [7].…”

Section: Introductionmentioning

confidence: 99%

Density Functional Theory in the Design of Organometallics for Energy Conversion

Freeman

Williams

2015

Green Chemistry and Sustainable Technology

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Theoretical methods based on density functional theory (DFT) and timedependent density functional theory (TD-DFT) are increasingly used to rationalise the excited-state properties of metal complexes and to help guide the design of new materials. This chapter provides a brief introduction of the background to such methods, highlighting some of the features that need to be considered, such as the ability of functionals to deal with charge-transfer states and the challenges associated with triplet-state calculations. Examples are drawn from recent studies on (1) the ground-state and light absorption properties of ruthenium(II) complexes as sensitisers for dye-sensitised solar cells (DSSCs) and (2) IntroductionMetal complexes and organometallics play a key role in many devices for energy conversion, particularly those where light is involved. For example, in the new generation of display screen equipment and energy-efficient lighting -organic light-emitting diodes (OLEDs) -the use of complexes of heavy transition metals as phosphorescent emitters allows large gains in efficiency through the harvesting of otherwise wasted triplet states [1]. Meanwhile, in the reverse process of light-toelectrical energy conversion, metal complexes that absorb light to generate chargetransfer states are at the forefront of research into dye-sensitised solar cells (DSSCs) [2]. Metal complexes with long excited-state lifetimes and that are strong excitedstate oxidants or reductants also attract attention in the field of 'artificial photosynthesis' (AP) -the conversion of light-to-chemical energy, for example, in

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The influence of casting solution structure on the microporosity of polyetherimide gas separation membranes prepared by the coagulation post-leaching method

Kurdi

Tremblay

2001

Journal of Membrane Science

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Metal Complexes

Cited by 3 publications

References 93 publications

Selective Media for Actinide Collection and Pre-Concentration: Results of FY 2006 Studies

Selective Media for Actinide Collection and Pre-Concentration: Results of FY 2006 Studies

Density Functional Theory in the Design of Organometallics for Energy Conversion

The influence of casting solution structure on the microporosity of polyetherimide gas separation membranes prepared by the coagulation post-leaching method

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