54290-40-3Relevant academic research and scientific papers
Rotational Barriers of Strained Olefines
Doering, William v. E.,Roth, Wolfgang R.,Bauer, Frank,Breuckmann, Rolf,Ebbrecht, Thomas,at al.
, p. 1263 - 1276 (2007/10/02)
For the olefins 1-8 heats of formation have been derived from heats of hydrogenation and force-field calculations, respectively.From the kinetics of their geometrical isomerisation the corresponding values for the transition states were obtained.The rotational barriers, which vary by nearly 30 kcal/mol, can be described by a unique torsional potential (65.9 +/- 0.9 kcal/mol), which is independent of the degree of substitution, if a correction is made for the steric energy contribution in the ground- and transition-states. - Key Words: Rotational barriers / Olefins, strained / Heat of Hydrogenation / Force-field calculation
Thermolabile Hydrocarbons, XVI. Thermal Stability, Strain Enthalpy, and structure of Sym. Tetrasubstituted Ethanes
Hellmann, Goetz,Hellmann, Siegried,Beckhaus, Hans-Dieter,Ruechardt, Christoph
, p. 3364 - 3383 (2007/10/02)
Activation parameters were determined for the thermolysis reaction of 12 sym. substituted ethanes ( Ct - Ct series).From product analysis it was concluded that the central Ct - Ct bond is cleaved in the rate determing step by homolysis.The correlation between δH* and the change in strain enthalpy during the activation process (MM2 calculations) points to nearly 20percent residual strain at transition state.From a comparison of the thermolysis data for Ct - Ct and Cq - Cq ethanes a 2.3 kcal/mol difference in stabilization energy for sek. and tert. alkyl radicals is derived as an upper limiting value.The influence of strain on bond lengths, bond angles, and torsional angles is compared for Ct - Ct and Cq - Cq ethanes.
