Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

B3LYP barriers

As the formation of betaines from amide-stabilized ylides is known to be reversible (in contrast with aryl- or semistabilized ylides, which can exhibit irreversible anti betaine formation see Section 1.2.1.3), the enantiodifferentiating step cannot be the C-C bond-forming step. B3LYP calculations of the individual steps along the reaction pathway have shown that in this instance ring-closure has the highest barrier and is most likely to be the enantiodifferentiating step of the reaction (Scheme 1.16) [25]. [Pg.14]

A thorough computational study of this process has been carried out using B3LYP/ONIOM calculations.31 The rate-determining step is found to be the formation of the rhodium hydride intermediate. The barrier for this step is smaller for the minor complex than for the major one. Additional details on this study can be found at ... [Pg.380]

According to B3LYP/6-31G computations of the intermediates and TSs, there are no large barriers to the reaction and it is strongly exothermic.156 Measured Ea values are around 10kcal/mol.157 The complexation of borane to the catalyst shifts electron density from nitrogen to boron and enhances the nucleophilicity of the hydride. The... [Pg.418]

Barrier Exp.a G2 HF SVWN SLYP BVWN BLYP B3LYP... [Pg.256]

Fig. 21. Reaction energetics and potential energy barriers of the C3H5 system, determined at the G2(B3LYP) level of theory. aC3H4 stands for allene and PC3H4 for propyne. (From Davis et al.146)... [Pg.498]

See other pages where B3LYP barriers is mentioned: [Pg.20]    [Pg.20]    [Pg.117]    [Pg.259]    [Pg.85]    [Pg.182]    [Pg.171]    [Pg.408]    [Pg.75]    [Pg.2287]    [Pg.20]    [Pg.20]    [Pg.117]    [Pg.259]    [Pg.85]    [Pg.182]    [Pg.171]    [Pg.408]    [Pg.75]    [Pg.2287]    [Pg.679]    [Pg.24]    [Pg.141]    [Pg.645]    [Pg.439]    [Pg.446]    [Pg.448]    [Pg.451]    [Pg.166]    [Pg.699]    [Pg.700]    [Pg.61]    [Pg.257]    [Pg.260]    [Pg.260]    [Pg.262]    [Pg.265]    [Pg.266]    [Pg.266]    [Pg.267]    [Pg.267]    [Pg.268]    [Pg.274]    [Pg.275]    [Pg.275]    [Pg.113]    [Pg.119]    [Pg.346]    [Pg.386]    [Pg.388]    [Pg.388]    [Pg.394]    [Pg.206]    [Pg.595]   
See also in sourсe #XX -- [ Pg.171 ]



SEARCH



B3LYP

© 2024 chempedia.info