Time filter

Source Type

Toulouse, France

Dognon J.-P.,CNRS Coordination Chemistry
Coordination Chemistry Reviews | Year: 2014

The chemical bonding in actinide compounds is usually analyzed by inspecting the shape and the occupation of the orbitals or by calculating bond orders which are based on orbital overlap and occupation numbers. However, this may not give a definite answer because the choice of the partitioning method may strongly influence the result leading sometimes to qualitatively different answers. This review highlights that the joint and complementary tools such as charge, orbital, quantum chemical topology and energy decomposition analyses are very powerful to understand chemical bonding in the field of actinide chemistry. However, understanding the actinide-ligand bond is not straightforward and requires caution in the use of these methods. This review is illustrated through applications to newly discovered bent actinocene compounds and actinide endohedral clusters fulfilling a 32-electron rule. © 2013 Elsevier B.V.

Lavigne G.,CNRS Coordination Chemistry
Angewandte Chemie - International Edition | Year: 2012

The selective redistribution of hydrocarbon chains C (n) on a polyhydrido triruthenium cyclopentadienyl complex (see scheme; Rured spheres) involves a repeated sequence of face-to-face C-H group transfers (A to C) through the open cluster B, followed by individual concerted skeletal rearrangements on the two faces (C to A'). This process is just one of several spectacular examples illustrating the power of a molecular polymetallic system. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Meunier B.,CNRS Coordination Chemistry
Angewandte Chemie - International Edition | Year: 2012

A bright future for small molecules: Drugs based on molecules made by chemists are far from old-fashioned. Although biopharmaceuticals developed during the last two decades may have caught the public's imagination, traditional drugs remain a strong force in the pharmaceutical industry. Effective, inexpensive small-molecule drugs are crucial in fighting diseases and maintaining cost-effective health care. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Pitie M.,CNRS Coordination Chemistry | Pratviel G.,Toulouse 1 University Capitole
Chemical Reviews | Year: 2010

A study was conducted to demonstrate activation of DNA carbon-hydrogen bonds by metal complexes. It was demonstrated that active species, formed by activation of O 2 or H 2O 2 with metal complexes was divided into three categories. The most commonly used metals in the field of oxygen activation and DNA damage were iron, copper, and manganese. It was also demonstrated that a triple helix strategy was necessary when sequence selective oxidation of a DNA duplex target was desired. Proteins were found to be alternative macromolecules that were able to selectively target large DNA sequences apart from oligonucleotides. A final strategy for targeting a metal complex to bind DNA consisted of the preparation of conjugates with agents able to form a covalent linkage with DNA.

Thuery P.,CNRS Coordination Chemistry
Crystal Growth and Design | Year: 2012

The crystal structures of the complexes formed under hydrothermal conditions by uranyl ions with 4-aminobenzoic (HL1), 4-amino-3-methylbenzoic (HL2), 4-(aminomethyl)benzoic (HL3), and 3-amino-5-hydroxybenzoic (HL4) acids, in the presence of cucurbit[6]uril (CB6), have been determined. These ligands have been chosen because, in their zwitterionic form, they display both a metal-complexing carboxylate group and an ammonium group able to associate with CB6 through ion-dipole and hydrogen bonding interactions. The complexes [H 2NMe 2] 2[(UO 2) 2(L1) 2O(OH)(H 2O)] 2•CB6•15H 2O (1) and [H 2NMe 2] 2[(UO 2) 2(L2) 2O(OH)(H 2O)] 2•CB6• 17H 2O (2) were obtained in the presence of dimethylformamide, which gives dimethylammonium ions in situ. The latter are held at the CB6 portals, while the tetranuclear uranyl complex with the aminobenzoate anions is not bound to CB6. The neutral, ammonium-containing form of the ligand is present in [UO 2(HL3)(OH)(HCOO)(H 2O)] 2•2CB6•2DMF•14H 2O (3), in which the di(μ 2-hydroxo)-bridged, dinuclear uranyl complex displays two diverging, monodentate HL3 ligands. The latter are associated with two CB6 molecules to give a dumbbell-shaped supramolecular assembly. Three CB6 molecules are assembled around a tetranuclear uranyl complex in [(UO 2) 4(HL3) 2(L3)O 2(OH) 2(H 2O) 4]•2CB6•0.5CB8•HL3•NO 3•20H 2O (4), with two of them being bridging and giving rise to a one-dimensional, linear supramolecular architecture. Finally, the 3-amino substituted ligand HL4 gives the highly symmetric complex [UO 2(HL4)(L4) 2]•3CB6•16H 2O (5), in which the uranyl ion is chelated by three carboxylate groups. Three CB6 molecules are assembled around the planar complex to give a triangular, discrete species. In compounds 3-5, the usual packing of CB6 molecules into columns or layers is not retained as it is frequently in the presence of uranyl complexes. This is due to the CB6-assembling role of the heterodifunctional ligands, which hold the CB6 molecules at the periphery of mono-, di-, or tetranuclear uranyl complexes of quite usual, planar geometry. © 2011 American Chemical Society.

Discover hidden collaborations