Kinetic and mechanism of the gas-phase pyrolysis of exo-2-norbornyl formate

- Pyrolysis of exo-2-norbornyl formate is homogeneous, unimolecular, and first-order.
- Unusual products formation in pyrolysis of esters with the presence of a CβH bond.
- Experimentals suggests a concerted three-membered cyclic transition state mechanism.

The rate coefficient of the gas-phase pyrolysis or elimination of exo-2-norbornyl formate was determined in a deactivated, static reaction vessel over the temperature range 300-350 °C and pressure range 41-105 Torr. The substrate exo-2-norbornyl formate yielded surprisingly exo-2-norborneol and CO gas. This reaction, in the presence or absence of the free radical inhibitor toluene, proved to be homogeneous, unimolecular and follows a first-order rate law. The rate of equation is given by the following Arrhenius equation: log k1 (s−1) = (13.85 ± 0.23) − (194.6 ± 2.7)kJ mol−1(2.303RT)−1, r = 0.9998.Experimental data suggested a semi-polar concerted three-membered cyclic transition state type of mechanism.

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