Le droit du recouvrement en ses aspects notariaux

peer reviewe

Metal-free reduction of CO2

Even if carbon dioxide is now considered a major pollutant and the main source of global warming, it remains the feedstock used by Nature to generate organic compounds. There is considerable interest to find chemical processes that could replace fossil fuels by CO2 to generate industrially relevant carbon containing molecules. Mostly relying on frustrated Lewis pair technology and on the nucleophilic activation of CO2 or reducing agents by organic Lewis bases, novel catalytic opportunities have emerged to affect the metal-free catalytic reduction of carbon dioxide

On the concept of frustrated Lewis pairs

In this concept article, we consider the notion of ‘frustrated Lewis pairs’ (FLPs). While the original use of the term referred to steric inhibition of dative bond formation in a Lewis pair, work in the intervening decade demonstrates the limitation of this simplistic view. Analogies to known transition metal chemistry and the applications in other areas of chemistry are considered. In the light of these findings, we present reflections on the criteria for a definition of the term ‘frustrated Lewis pair’. Segregation of the Lewis acid and base and the kinetic nature of FLP reactivity are discussed. We are led to the conclusion that, while an all-inclusive definition of FLP is challenging, the notion of ‘FLP chemistry’ is more readily recognized

Couplage de codes éléments finis et dynamique discrète de dislocations

National audienceLe calcul couplé entre la méthode des éléments finis et la dynamique discrète de dislocations est utilisé pour simuler le comportement cyclique d'un agrégat polycristallin. La convergence et la validation du couplage sont discutées

Aluminum complexes bearing fonctionalized trisamido ligands and their reactivity in the polymerization of ε-caprolactone and rac-lactide

The addition of 1 and 2 equivalents of AlMe3 to cis,cis-C6H9(NHCH2C6H4-o-R)3 (R = PPh2 (3) and SPh (4)) gives complexes [cis,cis-C6H9(NCH2C6H4-o-R-κN)2(NHCH2C6H4-o-R-κN)]AlMe (R = PPh2 (7) and SPh (8)) and [cis,cis-C6H9(NCH2C6H4-o-R)3-κ5μ2N]Al2Me3 (R = PPh2 (5) and SPh (6)), respectively. The bimetallic complexes are active in the polymerization of ε-caprolactone and rac-lactide whereas the monometallic complexes are not, although no cooperative behaviour is observed between the two aluminium atoms of 5 and 6. The polycaprolactone samples, which were characterized using 1H NMR, MALDI-TOF, and SEC, show the presence of residual ligands 3 or 4 bound to the polymer and the in situ NMR studies confirm that the insertion occurs in an Al–N bond