Electrochemical attachment of a conjugated amino-ferrocifen complex onto carbon and metal surfaces

International audienceThe attachment of a pi-conjugated amino-ferrocifen complex was electrochemically achieved either by direct oxidation of the amino group or via the oxidation of the ferrocene moiety. In the first case, the modification consists in oxidizing, at +0.70V/SCE, the amino moiety to its radical cation, which upon deprotonation from the amino group, yields all aminyl radical that may add onto the electrode surface. Alternatively, it is demonstrated that the amine moiety can be indirectly oxidized through an intramolecular electron transfer from the amino moiety to the ferrocenyl group after oxidation of the ferrocene part at +0.40 V. This can occur thanks to the conjugated pi system of the complex. More importantly. it is demonstrated that the covalent attachment of the complex can be achieved on glassy carbon, gold, and platinum surfaces whatever the approach used. The possible mechanisms for the covalent attachment are discussed. Interestingly, it is also shown that the amino-ferrocene compound adsorbs very well likely via pi stacking between grafted and non-grafted molecules. Nevertheless, the adsorbed molecules could be easily removed after passing the electrode in an ultrasonic bath. The electrode coverage was determined under various conditions by integration of the corresponding voltammograms. (C) 2008 Elsevier B.V. All rights reserved

Minyon’un düğünü

Johann Wolfgang Goethe'nin Sabah'ta yayımlanan Minyon'un Düğünü adlı romanının ilk ve son tefrikalarıTefrikada yazarın adı belirtilmemiştir

4-(3-Methoxy­phen­oxy)butyric acid

In the title compound, C11H14O4, an inter­mediate for the synthesis of a new kind of estrogen receptor modulator, all non-H atoms lie on a common plane (r.m.s. deviation = 0.0472 Å). All C—C bonds in the side chain are in a trans conformation, and the hydroxyl group is also trans to the methyl­ene chain. In the crystal structure, mol­ecules form centrosymmetric dimers showing a head-to-head arrangement which is stabilized by O—H⋯O hydrogen bonds. A weak C—H⋯O contact is also present

Effective field and universal mobility in high-k metal gate UTBB-FDSOI devices

session 1: parameter extractionInternational audienceThis paper aims at reviewing experimental and theoretical behaviors of universal mobility in high-k metal gate UTBB-FDSOI devices. Based on split-CV mobility measurements, the parameter η, characterizing the effective field, has been extracted for a large range of back voltages and temperatures in devices with various equivalent oxide thicknesses. We demonstrated that a nearly universal trend for the mobility with respect to the effective field can be obtained in the front inversion regime but is difficult to obtain in the back channel inversion regime. Keywords—FDSOI, universal mobility, effective field, coefficient η

(Eta6-arene) ruthenium(II) complexes and metallo-papain hybrid as Lewis acid catalysts of Diels-Alder reaction in water.

International audienceCovalent embedding of a (eta(6)-arene) ruthenium(II) complex into the protein papain gives rise to a metalloenzyme displaying a catalytic efficiency for a Lewis acid-mediated catalysed Diels-Alder reaction enhanced by two orders of magnitude in water

Nanoparticles loaded with ferrocenyl tamoxifen derivatives for breast cancer treatment.

International audienceFor the first time, two organometallic triphenylethylene compounds (Fc-diOH and DFO), with strong antiproliferative activity in breast cancer cells, but insoluble in biological fluids, were incorporated in two types of stealth nanoparticles (NP): PEG/PLA nanospheres (NS) and nanocapsules (NC). Their physicochemical parameters were measured (size, zeta potential, encapsulation and loading efficiency), and their biological activity was assessed. In vitro drug release after high dilution of loaded NPs was measured by estradiol binding competition in MELN cells. The influence of the encapsulated drugs on the cell cycle and apoptosis was studied by flow cytometry analyses. Notwithstanding potential drug adsorption at the NP surface, Fc-diOH and DFO were incorporated efficiently in NC and NS, which slowly released both compounds. They arrested the cell cycle in the S-phase and induced apoptosis, whose activity is increased by loaded NS. A decrease in their antiproliferative activity by the antioxidant alpha-tocopherol indicated that reactive oxygen species (ROS) may be involved. Therefore, nanosystems, containing for the first time a high load of anticancer organometallic triphenylethylenes, have been developed. Their small size and delayed drug release, combined with their enhanced apoptotic potential, are compatible with an increased persistence in the blood and a promising antitumour activity

A [3]Ferrocenophane polyphenol showing a remarkable antiproliferative activity on breast and prostate cancer cell lines

International audienc

Atypical McMurry Cross-Coupling Reactions Leading to a New Series of Potent Antiproliferative Compounds Bearing the Key [Ferrocenyl-Ene-Phenol] Motif

In the course of the preparation of a series of ferrocenyl derivatives of diethylstilbestrol (DES), in which one of the 4-hydroxyphenyl moieties was replaced by a ferrocenyl group, the McMurry reaction of chloropropionylferrocene with a number of mono-aryl ketones unexpectedly yielded the hydroxylated ferrocenyl DES derivatives, 5a–c, in poor yields (10%–16%). These compounds showed high activity on the hormone-independent breast cancer cell line MDA-MB-231 with IC50 values ranging from 0.14 to 0.36 µM. Surprisingly, non-hydroxylated ferrocenyl DES, 4, showed only an IC50 value of 1.14 µM, illustrating the importance of the hydroxyethyl function in this promising new series. For comparison, McMurry reactions of the shorter chain analogue chloroacetylferrocene were carried out to see the difference in behaviour with mono-aryl ketones versus a diaryl ketone. The effect of changing the length of the alkyl chain adjacent to the phenolic substituent of the hydroxylated ferrocenyl DES was studied, a mechanistic rationale to account for the unexpected products is proposed, and the antiproliferative activities of all of these compounds on MDA-MB-231 cells lines were measured and compared. X-ray crystal structures of cross-coupled products and of pinacol-pinacolone rearrangements are reported.The authors wish to thank P. Herson and J. Vaissermann for three crystal structure determinations and T. Cresteil for IC50 determinations. We thank Anh N’Guyen for full discussions. K.K.’s stay in Paris was supported through an European Community Marie Curie Fellowship (HMPT-CT-2000- 00186). We thank the Agence Nationale de la Recherche for financial support (ANR 2010 BLAN 7061 blanc “Mecaferrol”) and the Ministère des Affaires Etrangères for a doctoral fellowship (M.G.)