Kinetic studies conducted under both catalytic and stoichiometric conditions were employed to investigate the reductive elimination of RuPhos (2-dicyclohexylphosphino-2',6'-diisopropoxybiphenyl) based palladium amido complexes. These complexes were found to be the resting state in Pd-catalyzed cross-coupling reactions for a range of aryl halides and diarylamines. Hammett plots demonstrated that...

Twenty-three diarylcarbenium ions and 38 pi-systems (arenes, alkenes, allyl silanes and stannanes, silyl enol ethers, silyl ketene acetals, and enamines) have been defined as basis sets for establishing general reactivity scales for electrophiles and nucleophiles. The rate constants of 209 combinations of these benzhydrylium ions and pi-nucleophiles, 85 of which are first presented in this arti...

Traditional transport theory provides a closure of fluid equations that is valid in the collisional, short mean–free–path limit. The possibility of extending an analogous closure to long mean–free path is examined here. An appropriate kinetic equation, using a model collision operator, is solved rigorously for arbitrary collisionality but weak, Maxwellian source terms. The corresponding particl...

Octahedral ruthenium complexes of the type TpRu(L)(NCMe)R [Tp ) hydridotris(pyrazolyl)borate; R ) alkyl or aryl; L ) CO or PMe3] have been shown previously to initiate the C-H activation of aromatic substrates. In order to probe the nature of the C-H activation step, reaction rates have been theoretically obtained for the conversion of TpRu(L)(η-C,C-C6H5X)Me to TpRu(L)(p-C6H4X) and CH4 where X ...

ABSTRACT The kinetics and mechanism of the aromatic nucleophilic substitution reactions of 2,6-bis(trifluoromethanesulfonyl)-4-nitroanisole with para-X-substituted anilines (X = OH, OMe, Me, H, F, I, Cl) were studied in MeOH-Me2SO mixtures and pure Me2SO at 25.0 °C. The second-order rate coefficients depend on the substitutent in aniline and give good Hammett and Brønsted correlations; a polar ...

The direct quantitative correspondence between theoretical predictions and the measured plasma fluctuations and transport is tested by performing nonlinear gyro-Landau-fluid simulations with the GRYFFIN ~or ITG! code @W. Dorland and G. W. Hammett, Phys. Fluids B 5, 812 ~1993!; M. A. Beer and G. W. Hammett, Phys. Plasmas 3, 4046 ~1996!#. In an L-mode reference discharge in the DIII-D tokamak @J....

Raloxifene and arzoxifene are benzothiophene selective estrogen receptor modulators (SERMs) of clinical use in postmenopausal osteoporosis and treatment of breast cancer and potentially in hormone replacement therapy. The benefits of arzoxifene are attributed to improved bioavailability over raloxifene, whereas the arzoxifene metabolite, desmethylarzoxifene (DMA) is a more potent antiestrogen. ...

Three distinct procedures for obtaining the effective Gibbs energies of activation from computed a reaction involving multiple reactant-state (RS) and transition-state (TS) conformers are shown to be equivalent. If Boltzmann-weighted average RS TS evaluated, then energy contribution entropy mixing both must also included in order obtain correct value activation. Application solvolytic 4,4′-dime...

Este ensaio busca analisar as masculinidades dos personagens detetivescos na ficção policial. Partindo do personagem Dupin, o detetive racional de Edgar Allan Poe, e passando por Philip Marlowe Sam Spade, os detetives “durões” Raymond Chandler Dashiell Hammett, respectivamente, pretendo me ater ao Espinosa, Luiz Alfredo Garcia-Roza, selecionando para análise romance O silêncio da chuva. Alio-me...

Evaluation of a new proton sponge, bis-1,1,8,8-(tetramethylguanidino)naphtalene (TMGN), in substituted phenols O-alkylation by methyl iodide in DMF has been studied. Kinetic measurements were performed in N,N-dimethylformamide-d7 and followed by H NMR using stoichiometric amounts of reagents. Plot of the results shows that the reaction follows an almost perfect second order rate law. However th...