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51.
Albert J Cadena JM González A Granell J Solans X Font-Bardia M 《Chemical communications (Cambridge, England)》2003,(4):528-529
The first NH aldimine organometallic derivative is unexpectedly formed by the cleavage of the nitrogen-carbon bond of the amino acid fragment of the Schiff base 2,4,6-Me3C6H2CH=NCH(CH2Ph)COOEt when the imine is treated with palladium acetate. 相似文献
52.
Maksym Dekhtiarenko Dr. Simon Pascal Dr. Mourad Elhabiri Valerie Mazan Dr. David Canevet Magali Allain Dr. Vincent Carré Prof. Frédéric Aubriet Prof. Zoia Voitenko Prof. Marc Sallé Dr. Olivier Siri Dr. Sébastien Goeb 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(64):15922-15927
The development of methodologies to control on demand and reversibly supramolecular transformations from self-assembled metalla-structures requires the rational design of architectures able to answer to an applied stimulus. While solvent or concentration changes, light exposure or addition of a chemical have been largely explored to provide these transformations, the case of pH sensitive materials is less described. Herein, we report the first example of a pH-triggered dissociation of a coordination-driven self-assembled interlocked molecular link. It incorporates a pH sensitive benzobisimidazole-based ligand that can be selectively protonated on its bisimidazole moieties. This generates intermolecular electrostatic repulsions that reduces drastically the stability of the interlocked structure, leading to its dissociation without any sign of protonation of the pyridine moieties involved in the coordination bonds. Importantly, the dissociation process is reversible through addition of a base. 相似文献
53.
Dr. Aude Sourdon Dr. Magali Gary-Bobo Dr. Marie Maynadier Dr. Marcel Garcia Dr. Jean-Pierre Majoral Dr. Anne-Marie Caminade Dr. Olivier Mongin Dr. Mireille Blanchard-Desce 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(14):3637-3649
The synthesis and the photophysical properties of a new class of fully organic monodisperse nanoparticles for combined two-photon imaging and photodynamic therapy are described. The design of such nanoparticles is based on the covalent immobilization of a dedicated quadrupolar dye that combines excellent two-photon absorbing (2PA) properties, fluorescence and singlet oxygen generation ability, in a phosphorous-based dendrimeric architecture. First, a bifunctional quadrupolar dye bearing two different grafting moieties, a phenol function and an aldehyde function, was synthesized. It was then covalently grafted through its phenol function to a phosphorus-based dendrimer scaffold of generation 1. The remaining aldehyde functions were then used to continue the dendrimer synthesis up to generation 2, introducing finally 24 water-solubilizing triethyleneglycol chains at its periphery. A dendrimer confining 12 photoactive quadrupolar units in its inner scaffold and showing water solubility was thus obtained. Interestingly, the G1 and G2 dendrimers retain some fluorescence as well as significant singlet oxygen production efficiencies while they were found to show very high 2PA cross-sections in a broad range of the NIR biological spectral window. Hydrophilic dendrimer G2 was tested in vitro on breast cancer cells, first in one- and two-photon microscopy, which allowed for visualization of their cell internalization, then in two-photon photodynamic therapy. While being nontoxic in the dark and, more importantly, under exposure to daylight, dendrimer G2 proved to be a very efficient cell-death inducer only under two-photon irradiation in the NIR. 相似文献
54.
55.
Dr. Khrystyna Herasymchuk Magali Allain Gregory A. MacNeil Dr. Vincent Carré Prof. Frédéric Aubriet Prof. Daniel B. Leznoff Prof. Marc Sallé Dr. Sébastien Goeb Prof. Tim Storr 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(65):16161-16172
The incorporation of a redox-active nickel salen complex into supramolecular structures was explored via coordination-driven self-assembly with homobimetallic ruthenium complexes (bridged by oxalato or 5,8-dihydroxy-1,4-naphthoquinato ligands). The self-assembly resulted in the formation of a discrete rectangle using the oxalato complex and either a rectangle or a catenane employing the larger naphthoquinonato complex. The formation of the interlocked self-assembly was determined to be solvent and concentration dependent. The electronic structure and stability of the oxidized metallacycles was probed using electrochemical experiments, UV-Vis-NIR absorption, EPR spectroscopy and DFT calculations, confirming ligand radical formation. Exciton coupling of the intense near-infrared (NIR) ligand radical intervalence charge transfer (IVCT) bands provided further confirmation of the geometric and electronic structures in solution. 相似文献
56.
Olive Recombinant Hydroperoxide Lyase,an Efficient Biocatalyst for Synthesis of Green Leaf Volatiles
57.
58.
Fabien Lamoureux Jean-michel Gaulier François-Ludovic Sauvage Magali Mercerolle Christine Vallejo Gérard Lachâtre 《Analytical and bioanalytical chemistry》2009,394(7):1895-1901
The detection of ethyl-β-d-6-glucuronide (EtG), a stable phase II metabolite of ethanol, is of interest in both clinical and forensic contexts with
the aim of monitoring alcohol abuse. We present a liquid chromatography-electrospray ionisation-tandem mass spectrometry method
for the detection and quantification of EtG in hair. Thirty milligrams of washed and cut hair were cleaned up using solid-phase
extraction graphite cartridges. Separation was then performed using an Uptisphere-3SI column, and the detection was operated
in the negative mode. After validation, the method was applied to hair samples taken from four fatalities (F) with documented
excessive drinking habits, 12 heavy drinkers (HD) and seven social drinkers (SD). The method exhibits limits of detection
and quantification of 4 and 10 pg/mg, respectively. Intra- and inter-assay standard deviation and relative bias were less
than 20% over the calibrating range (10 to 3,000 pg/mg). EtG hair concentrations in SD were <10 pg/mg and >50 pg/mg for F
and HD (range, 54 to 497 pg/mg). The present assay appears convenient to carry out owing to the very small quantity of hair
samples required to determine an effective heavy alcohol consumption (EtG hair concentration >50 pg/mg). 相似文献
59.
Rodrigues MA Bemquerer MP Mohallem ND Politi MJ 《Langmuir : the ACS journal of surfaces and colloids》2006,22(21):8939-8944
A nanohybrid xerogel (XDPN) was obtained from a tetraethyl orthosilicate (TEOS) condensation reaction in the presence of N,N'-bis(2-phosphonoethyl)-1,4,5,8-naphthalenediimide (DPN). Physical and chemical characterization of the materials revealed that the XDPN morphology is quite different from that of xerogel without DPN (X). Photochemical and photophysical studies of the hybrid material showed that XDPN is efficient in promoting the photosensitization of tryptophan radical formation, and the radical species are stabilized due to the presence of DPN aggregates in the material. Radical stabilization can also be observed for DPN in solution but only for concentrations in the millimolar range. 相似文献
60.
Using a radial flow chamber, we study Saccharomyces cerevisiae kinetics of detachment from stainless steel substrates. Samples of similar surface chemistry, but with different surface topologies are compared: mirror polished and electro-chemically etched. Different grain sizes (20, 40 and 100 microm) and different etching depths (100-650 nm) are tested. Cells are removed from the substrate according to a first-order kinetics defining two macroscopic parameters that depend on the applied stress: the detachment efficiency and the detachment rate constant. Whatever the surface topology, detachment occurs above a threshold and its rate is strongly stimulated by the applied stress. The detachment efficiency is characterized by the shear stress at which half of the cells detach and is independent of surface topology. In contrast, detachment is faster from etched than mirror polished surfaces. Finally, we also show the preferential adhesion of yeast cells to grains of < 001 > crystallographic orientation with respect to the surface. 相似文献