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Journal ArticleDOI

Actinide-specific complexing agents: their structural and solution chemistry

01 Apr 1984-Inorganica Chimica Acta (Elsevier)-Vol. 94, Iss: 4, pp 193-204
TL;DR: In this article, a series of tetracatecholate ligands designed to be specific for Pu(IV and other actinide(IV) ions has been achieved, but the results indicate that the reduction potential of free Am(IV)/(III) is probably greater than or equal to + 2.6 V vs NHE or higher.
About: This article is published in Inorganica Chimica Acta.The article was published on 1984-04-01 and is currently open access. It has received 60 citations till now. The article focuses on the topics: Oxidation state.

Summary (1 min read)

Eu(III), the homolog of Am(III).

  • Originally it was thought that complexation of Am(III) jji vivo by cate:'iolate ligands would not be of sufficient stability to remove Am(III) from test animals.
  • These curves indicate that for the dogs injected with the catechol ligand the amount of Am in the plasma is increased and retained.
  • (See the decrease in concen tration for the "untreated" clearance curve.).
  • One possible explanation is that the catecholate ligand is facili tating oxidation of Am(III) to Am(IV) and promoting the formation of a very stable transferrin complex similar to that of Pu(IV).
  • Titrations of Eu(III) with 3,4,3-LICAMS indicate that a complex is formed whereby 1.5 catechol arms bind Eu(III) at pH 5.5.

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01 Jan 2015
TL;DR: In this article, an origin of sensing function of polyelectrolyte-coated colloids based on Tb(III) complexes with calix[4]resorcinarene cavit and bearing four 1,3-diketone groups at the upperrim is introduced.
Abstract: The present work introduces an origin of sensing function of polyelectrolyte-coated colloids based onTb(III) complexes with calix[4]resorcinarene cavitand bearing four 1,3-diketone groups at the upperrim. The Tb(III)-centered luminescence of the colloids remains unchanged at pH 3–9, although theTb(III) complexes are highly pH-dependent in DMF solutions. Both colloidal and luminescent proper-ties of the colloids are stable within one month at least, which reveals stability of complex-based hardnanotemplates and soft polyelectrolyte deposition. The chelating substrates (catechol, tetracycline andfluoroquinolone derivatives)inducequickandreproducibleluminescentresponseofthecomplex-basedcolloids without any detectable changes of their colloidal properties. The ternary complex formation atthe interface of the colloids is the reason for their luminescent response on the substrates in aqueoussolutions. BoththeinsolubilityoftheTb(III)-containingcoresandtheshieldingand/orbuffereffectofthepolyelectrolyte coating affect the interfacial complex formation, which results in more selective lumi-nescent response of the colloids on the tetracycline and fluoroquinolone antibiotics in comparison withthe complexes in solutions.© 2015 Elsevier B.V. All rights reserved.

430 citations

Journal ArticleDOI
TL;DR: Pyochelin (Pch) is one of the two major siderophores produced and secreted by Pseudomonas aeruginosa PAO1 to assimilate iron and FptA has broad metal specificity at the binding stage but is much more selective for the metal uptake process.
Abstract: Pyochelin (Pch) is one of the two major siderophores produced and secreted by Pseudomonas aeruginosa PAO1 to assimilate iron. It chelates iron in the extracellular medium and transports it into the cell via a specific outer membrane transporter, FptA. We used the fluorescent properties of Pch to show that this siderophore chelates, in addition to Fe(3+) albeit with substantially lower affinities, Ag(+), Al(3+), Cd(2+), Co(2+), Cr(2+), Cu(2+), Eu(3+), Ga(3+), Hg(2+), Mn(2+), Ni(2+), Pb(2+), Sn(2+), Tb(3+), Tl(+), and Zn(2+). Surprisingly, the Pch complexes with all these metals bound to FptA with affinities in the range of 10 nM to 4.8 microM (the affinity of Pch-Fe is 10 nM) and were able to inhibit, with various efficiencies, Pch-(55)Fe uptake in vivo. We used inductively coupled plasma atomic emission spectrometry to follow metal uptake by P. aeruginosa. Energy-dependent metal uptake, in the presence of Pch, was efficient only for Fe(3+). Co(2+), Ga(3+), and Ni(2+) were also transported, but the uptake rates were 23- to 35-fold lower than that for Fe(3+). No uptake was seen for all the other metals. Thus, cell surface FptA has broad metal specificity at the binding stage but is much more selective for the metal uptake process. This uptake pathway does not appear to efficiently assimilate any metal other than Fe(3+).

172 citations

Journal ArticleDOI
TL;DR: Ligand applications as diverse as iron removal or supplementation, contrast agents in imaging applications, and mobilization of undesirable excess metal ions will be surveyed herein.
Abstract: The family of hydroxypyrones and close congeners, the hydroxypyridinones, is a particularly versatile class of ligands. The most widely investigated for medicinal applications are the 3-hydroxy-4-pyrones and the 1,2- 3,2- and 3,4-hydroxypyridinones. Key features of these ligands are: a six-membered ring, with a ring N or O atom either ortho or para to a ketone group, and two ortho exocyclic oxygen atoms. Readily functionalizable, the hydroxypyrones and hydroxypyridinones allow one to achieve a range of di- and trivalent metallocomplex stabilities and can include tissue or molecular targeting features by design. Research over the past several decades has greatly expanded the array of ligands that are the subject of this critical review. Ligand applications as diverse as iron removal or supplementation, contrast agents in imaging applications, and mobilization of undesirable excess metal ions will be surveyed herein.

130 citations

Journal ArticleDOI
TL;DR: In this paper, the UO22+ coordination chemistry of several prototypic expanded porphyrins is reviewed, and the ability of these expanded polypyrrolic ligands to stabilize complexes containing the uranyl cation is contrasted to that of the porphrin system.

77 citations

References
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01 Jan 1972
TL;DR: In this article, inorganic chemistry principles of structure and reactivity are presented. But, they do not cover how to use these principles in the design of products, and they are not available in any type of product.
Abstract: INORGANIC CHEMISTRY PRINCIPLES OF STRUCTURE AND REACTIVITY JAMES E HUHEEY PDF Are you looking for Ebook inorganic chemistry principles of structure and reactivity james e huheey PDF ? You will be glad to know that right now inorganic chemistry principles of structure and reactivity james e huheey PDF is available on our online library. With our online resources, you can find inorganic chemistry principles of structure and reactivity james e huheey or just about any type of ebooks, for any type of product.

2,814 citations