Diffusion control of the Diels—Alder reaction rate at elevated pressures

Kiselev, V. D.; Kashaeva, E. A.; Shihab, Mahdi S.; Potapova, L. N.; Iskhakova, G. G.

doi:10.1023/b:rucb.0000024827.64458.0f

Cited by 10 publications

(1 citation statement)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…With respect to viscosity as it is shown in next section (Figure 19 and Figure 20), PUFAM systems show higher viscosity than PUDA systems. A slight increase in the DA reaction rate constant has been related in literature in the frame of a possible cage effect of the solvent [52]. In as similar way, the behavior observed in our work for the PUFAM system can be related to the high viscosity which increases the cage effect, providing higher DA conversions.…”

Section: Thermal Reversibility Studysupporting

confidence: 89%

One pot stimuli-responsive linear waterborne polyurethanes via Diels-Alder reaction

Aizpurua

Martin

Formoso

et al. 2019

Progress in Organic Coatings

View full text Add to dashboard Cite

Section: Thermal Reversibility Studysupporting

confidence: 89%

One pot stimuli-responsive linear waterborne polyurethanes via Diels-Alder reaction

Aizpurua

Martin

Formoso

et al. 2019

Progress in Organic Coatings

View full text Add to dashboard Cite

Diels–Alder Reactions of Inert Aromatic Compounds within a Self‐Assembled Coordination Cage

Horiuchi

Murase

Fujita

2011

Chemistry An Asian Journal

View full text Add to dashboard Cite

A self-assembled coordination cage serves as a nanometer-sized molecular flask to promote the Diels-Alder reactions of aromatic hydrocarbons with N-cyclohexylmaleimide. The coordination cage accelerated the Diels-Alder reaction of anthracene at the electronically unfavorable, terminal benzene ring to give a compact, cavity-restrained syn-adduct. Activation-parameter measurements for the reactions revealed considerable reduction in the entropy cost, and preorganization of the substrates is a dominant factor in the enhanced reactivity. Owing to this entropy-cost reduction, otherwise-unreactive aromatic compounds, such as naphthalenes or triphenylene, also underwent Diels-Alder reactions in a regio- and stereocontrolled fashion. In the naphthalene Diels-Alder reaction, X-ray crystallographic analysis of the guest-inclusion complex clarified the reinforced orientation and proximity of the substrate pairs before the reaction. A perylene Diels-Alder adduct was stabilized inside the cage and protected from aerial oxidation.

show abstract

Diels-Alder reaction volumes in the solid state and solution

et al. 2004

Self Cite

View full text Add to dashboard Cite

The densities of anthracene, tetracyanoethylene, maleic anhydride, N phenylmaleineimide, trans,trans 1,4 diphenylbuta 1,3 diene, and their Diels-Alder adducts were measured in the solid state and in solution at 25 °С. The reaction volumes in the solid state were calculated from the difference in molar volumes. They turned out to be low, close to each other (-4 to -11 cm 3 mol -1 ), and slightly different from the reaction volumes (-8±1 cm 3 mol -1 ) calcu lated from the van der Waals radii. The reaction volumes in solutions (-15 to -32 cm 3 mol -1 ) were found from the difference in partial molar volumes of the reactants in dioxane, acetoni trile, and 1,2 dichloroethane, The experimental Diels-Alder reaction volumes in solution are determined not only by the formation of new bonds in an adduct: a considerably higher contribution (to 75%) is made by a change in the volume of intermolecular empty spaces in solution on going from reactants to adducts.A change in the volume on going from the initial to transition or final state of a reaction corresponds to an activation volume (∆V ≠ ) or reaction volume (∆V ). The activation or reaction volumes can be calculated from the plot of the free activation energy (dG ≠ /∂p, Eq. (1)) or free reaction energy (∂G/∂p, Eq. (2)) vs. external pres sure (p).(dlnk/dp) Т = -1/RT (dG ≠ /dp) Т = -∆V ≠ /RT,(dlnK/dp) Т = -1/RT (dG/dp) Т = -∆V/RT.The reaction volumes determined independently from the difference in partial molar volumes of the products and reactants are usually close to the values calculated by Eqs (1) and (2). 1 The activation volumes can be deter mined only from the plot of the rate constant vs. external pressure. In common belief, 2-4 the sign and value of an activation volume provide additional information on the mechanism of the chemical reaction. In several cases, the pressure effect on the rate or equilibrium of reactions (Eqs (1) and (2)) can be caused by an energy contribution р∆V ≠ or р∆V and also by a change in the properties of the solvent due to a pressure increase. For instance, for reac tions with a high polar transition state, an elevated pres sure can affect the process rate due to the contribution р∆V ≠ and also due to an increase in the dielectric constant of the solvent. 1,5 Several examples are known for which an elevated pressure results in a significant increase in the viscosity of the medium, and the diffusion rate can be come determining even for comparatively slow pro cesses. 6,7 In catalytic reactions, an elevated pressure can change the concentration of active species and thus change the reaction rate. 2-4In the absence of similar complications under an el evated pressure, the volume parameters can reliably be determined from relations (1) and (2).Another question arises: what is an origin for the values of activation and reaction volumes? In the first approxi mation, it seems evident that, when a transition state and adducts are achieved, a decrease in the volume of a sys tem in the addition and cycloaddition reactions is caused by the formation...

show abstract

Diffusion control of the Diels—Alder reaction rate at elevated pressures

Cited by 10 publications

References 13 publications

One pot stimuli-responsive linear waterborne polyurethanes via Diels-Alder reaction

One pot stimuli-responsive linear waterborne polyurethanes via Diels-Alder reaction

Diels–Alder Reactions of Inert Aromatic Compounds within a Self‐Assembled Coordination Cage

Diels-Alder reaction volumes in the solid state and solution

Contact Info

Product

Resources

About