Thermal reorganizations of C6H8 hydrocarbons

Dolbier, William R. Jr.; Akiba, Kin Ya; Riemann, J. Michael; Harmon, C. A.; Bertrand, M.; Bézaguet, Alain-Arthur; Santelli, Maurice

doi:10.1021/ja00745a020

Cited by 40 publications

(36 citation statements)

References 1 publication

(3 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…This concerted motion ultimately causes breakage of both distal cyclopropane bonds at tϭ280 fs, yielding a diallyl diradical intermediate, for which experimental evidence has been reported. 16,36,37 After switching off the flooding potential, the system relaxes towards the product state. The activation free energy for this reaction has not yet been measured; we estimate it as 75 kcal/mol.…”

Section: Resultsmentioning

confidence: 99%

Predicting unimolecular chemical reactions: Chemical flooding

Müller

Meijere

Grubmüller

2002

The Journal of Chemical Physics

View full text Add to dashboard Cite

We present a method to predict products, transition states, and reaction paths of unimolecular chemical reactions such as dissociation or rearrangement reactions of small to medium sized molecules. The method thus provides the necessary input for established procedures to compute barrier heights and reaction rates, which conventionally have to be assumed heuristically. The method is an extension of the force field based conformational flooding procedure, but here aims at an accelerated barrier crossing of chemical reactions rather than conformational motions. Accordingly, it is now coupled to density functional molecular dynamics, such that the chemical reaction under study takes place at the picoseconds time scale set by todays computer technology. Barrier crossings are accelerated by means of an additional energy term (flooding potential) that locally destabilizes the educt conformation without affecting possible transition states or product states. The method is applied to two test systems, bicyclopropylidene and methylenecyclopropane, for which the reaction paths are predicted correctly. New details of reaction pathways are found, such as a transient concerted, but asynchronous rotation of the two methylene groups for the bicyclopropylidene --> methylenespiropentane reaction. Our method can be applied to simulations in the gas phase as well as in solution and can be combined with force field simulations, e.g., in hybrid density functional/force field (QM/MM) computations. (C) 2002 American Institute of Physics

show abstract

Section: Resultsmentioning

confidence: 99%

Predicting unimolecular chemical reactions: Chemical flooding

Müller

Meijere

Grubmüller

2002

The Journal of Chemical Physics

View full text Add to dashboard Cite

show abstract

“…Analogous transformations have been reported for isomeric tetramethylbicyclopropylidenes,7b,7c dichlorotetramethylbicyclopropylidenes7d and 1,1‐dideuteriobicyclopropylidene 7e. The mechanistic, kinetic and preparative aspects of these reactions have been reviewed 6a,8.…”

Section: Introductionmentioning

confidence: 81%

The Thermal Transformations of Bicyclopropylidene and Methylenespiropentane Revisited

et al. 2007

View full text Add to dashboard Cite

show abstract

“…Pyrolysis of methylenespiropentane 11 at 320'C gives both 1,2-and 1,3-bismethylenecyclobutane, 12 and 13, in the kinetic ratio of about 7:1(14, 15) (Scheme I). The reaction leading to 12 may be formulated (14,15) via the trimethylenemethane 14, formed by cleavage of the allylic radial bond (reaction A). This step is followed by cleavage of the peripheral bond to give the tetramethyleneethane 15.…”

mentioning

confidence: 99%

“…This step is followed by cleavage of the peripheral bond to give the tetramethyleneethane 15. An alternative, albeit energetically less attractive, path might be imagined (14,15) in which the order of bond cleavages is reversed, so that the peripheral bond breaks first (reaction B) to give biradical 16.…”

mentioning

confidence: 99%