Publication Type |
Journal Article |
Title |
Energetics of tert-Butoxyl Addition Reaction to Norbornadiene: A Method for Estimating the pi-Bond Strength of a Carbon-Carbon Double Bond |
Authors |
Paulo M. Nunes Silvia G. Estacio Gustavo T. Lopes Filipe Agapito R.M. Borges dos Santos Benedito J. Costa Cabral Jose A. Martinho Simoes |
Groups |
|
Journal |
JOURNAL OF PHYSICAL CHEMISTRY A |
Year |
2009 |
Month |
June |
Volume |
113 |
Number |
23 |
Pages |
6524-6530 |
Abstract |
The energetics of tert-butoxyl radical addition reaction to norbornadiene was investigated by time-resolved photoacoustic calorimetry (TR-PAC). The result, together with the C-O bond dissociation enthalpy (BDE) in the addition product, allowed us to calculate the pi-bond dissociation enthalpy in norbornadiene. Quantum chemistry (QC) methods were also used to obtain several enthalpies of reaction of the addition of oxygen-centered radicals to alkenes. The pi-bond dissociation enthalpies in these molecules were calculated by a procedure similar to that used in the case of norbornadiene and were compared with the pi-BDE values obtained by the method proposed by Benson. These two different approaches yield similar values for the pi-BDEs in alkenes, indicating that the addition method proposed in the present study is a valid way to derive that quantity. The influence of strain in the pi-BDEs of cyclic alkenes was investigated and allowed us to justify the difference between the pi-BDE in norbornene and norbornadiene. Finally, the thermochemistry of the addition and abstraction reactions involving these two molecules and tert-butoxyl radical was analyzed. |
DOI |
http://dx.doi.org/10.1021/jp900089t |
ISBN |
|
Publisher |
AMER CHEMICAL SOC |
Book Title |
|
ISSN |
1089-5639 |
EISSN |
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Conference Name |
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Bibtex ID |
ISI:000266679100018 |
Observations |
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