Search results for "C coupling"
showing 10 items of 149 documents
Carbocatalytic Oxidative Dehydrogenative Couplings of (Hetero)Aryls by Oxidized Multi‐Walled Carbon Nanotubes in Liquid Phase
2019
HNO3-oxidized carbon nanotubes catalyze oxidative dehydrogenative (ODH) carbon-carbon bond formation between electron-rich (hetero)aryls with O-2 as a terminal oxidant. The recyclable carbocatalytic method provides a convenient and an operationally easy synthetic protocol for accessing various benzofused homodimers, biaryls, triphenylenes, and related benzofused heteroaryls that are highly useful frameworks for material chemistry applications. Carbonyls/quinones are the catalytically active site of the carbocatalyst as indicated by model compounds and titration experiments. Further investigations of the reaction mechanism with a combination of experimental and DFT methods support the compet…
Soil erosion modelling: A bibliometric analysis.
2021
16 Pags.- 12 Figs.- 8 Tabls.
Synthesis and characterization of a novel dicyanamide-bridged Co(II) 1-D coordination polymer with a N 4 -donor Schiff base ligand
2017
The synthesis, structure and magnetic properties of a novel Co(II) 1D coordination polymer, [Co(L)(µ1,5-dca)(ClO4)2·MeOH]n (1) are described. Compound 1 contains two independent cationic Co(II) chains (CoA and CoB) which are parallel to the c direction and present short π-π and C-H⋯π interactions with two neighbouring chains along the b direction, giving rise to alternating layers of chains A and B in the bc plane. Variable-temperature magnetic susceptibility measurements shows a weak antiferromagnetic coupling among the adjacent cobalt(II) centres mediated through μ1,5-dca− bridge.
Rôle des espèces sulfures dans la corrosion des aciers non alliés : hétérogénéités de la couche de produits de corrosion et couplages galvaniques
2014
The present study relates to the problem of the long-term interim storage of nuclear wastes. In France, it is envisaged that high-level radioactive wastes will be confined in a glass matrix, stored in a stainless steel canister, itself placed in a carbon steel overpack. The wastes will then be stored at a depth of ~450 m in a deep geological disposal, drilled in a very stiff (indurated) clay (argillite) formation. A temperature as high as 90°C is expected at the steel surface because of the intense radioactivity. Anodic polarization at applied current density was used to synthetize corrosion product layers likely to be formed in storage conditions. The S235 steel electrodes were covered by …
Electronic Structure Modulation in an Exceptionally Stable Non-Heme Nitrosyl Iron(II) Spin-Crossover Complex
2016
The highly stable nitrosyl iron(II) mononuclear complex [Fe(bztpen)(NO)](PF6)(2) (bztpen=N-benzyl-N,N',N'-tris(2-pyridylmethyl)ethylenediamine) displays an S=1/2 S=3/2 spin crossover (SCO) behavior (T-1/2=370 K, Delta H= 12.48 kJmol(-1), Delta S=33 JK(-1) mol(-1)) stemming from strong magnetic coupling between the NO radical (S=1/2) and thermally interconverted (S=0 S=2) ferrous spin states. The crystal structure of this robust complex has been investigated in the temperature range 120-420 K affording a detailed picture of how the electronic distribution of the t(2g)-e(g) orbitals modulates the structure of the {FeNO}(7) bond, providing valuable magneto-structural and spectroscopic correlat…
Antiproliferative agents that interfere with the cell cycle at the G(1)-->S transition: further development and characterization of a small library o…
2008
In this continuation of our research on derivatives containing the stilbene privileged structure or that are derived from it, we report the results of further studies carried out on the previously initiated collection of compounds. We used a parallel synthetic approach to rapidly obtain small sets of compounds and started the annotation of the library in progress by calculating some physicochemical properties to be eventually correlated with biological activities. A pharmacophore for the antiproliferative activity was also built to summarize the features of the library. We evaluated the antiproliferative and pro-apoptotic activities of all compounds as well as the cell-cycle effects of some…
A heteropentanuclear oxalato-bridged [ReIV 4GdIII] complex: synthesis, crystal structure and magnetic properties
2012
The compound (NBu 4) 5[Gd III{Re IVBr 4(μ-ox)} 4(H 2O)]·H 2O (1), with intramolecular antiferromagnetic coupling, is the first Re(iv) system incorporating a 4f ion. © 2012 The Royal Society of Chemistry.
Is small and medium-sized beautiful? The structure and evolution of family SMEs research
2021
PurposeThe field of scientific research on small and medium-sized family businesses has been growing exponentially and the aim of this paper is to systematize the body of knowledge to develop an agenda for the future.Design/methodology/approachAdopting comparative bibliometric analyses on 155 articles (from 1989 until 2018) the authors provide a systematic assessment of the scientific research about small family firms, unveiling the structure and evolution of the field. Bibliographic coupling, co-citation analysis and co-occurrence analysis are adopted to identify the most influential studies and themes.FindingsFour clusters of research are reviewed: succession in family SMEs, performances …
Théorie des spectres rovibroniques des molécules octaédriques : Hamiltonien et moments de transition
2002
This thesis is devoted to the treatment of rovibronic couplings of octahedral species for which the Born-Oppenheimer approximation is broken down. By using the octahedral formalism, a full effective rovibronic model is extended from works about molecules in a non-degenerate electronic state. This effective model is dedicated to molecules with an odd or an even number of electrons and it has been successfully applied to V(CO)6 and ReF6. For both of them we have four interacting vibronic sublevels attributed to a dynamical Jahn-Teller effect and giving rise to very complicated spectra. This model is validated by the overall agreement between predicted and observed band profiles. Moreover, an …
Fullerene-ionic-liquid conjugates: a new class of hybrid materials with unprecedented properties.
2015
A modular approach has been followed for the synthesis of a series of fullerene-ionic-liquid (IL) hybrids in which the number of IL moieties (two or twelve), anion, and cation have been varied. The combination of C60 and IL give rise to new unique properties in the conjugates such as solubility in water, which was higher than 800 mg mL(-1) in several cases. In addition, one of the C60 -IL hybrids has been employed for the immobilization of palladium nanoparticles through ion exchange followed by reduction with sodium borohydride. Surprisingly, during the reduction several carbon nanostructures were formed that comprised nano-onions and nanocages with few-layer graphene sidewalls, which have…