ACTIVATION PARAMETERS AND RELATION OF ACTIVATION ENTROPY WITH SOLVENT POLARITY IN THERMAL REARRANGEMENT OF 7,7-DICHLORO-[a,c]- DIBENZO-[4,1,0]-BICYCLOHEPTANE

Document Type : Research Paper

Authors

1 Not- mentioned

2 Not-mentioned

Abstract

Thermal rearrangement of 7,7-dichloro-[a,c]-dibenzo-[4,1,0]-bicycloheptane (1) to 5,6-dichloro-5Hdibenzo-[
a,c]-cycloheptene (2) was studied in the solid phase and in solvents with different polarities. The
first-order constants at various temperatures for the rearrangement process were evaluated from the
absorption time data. The activation parameters for this rearrangement were obtained from the temperature
dependent of the rate constants. Variation of solvent polarity has no influence on Ea, but a marked
difference in ΔS# is observed. Abinitio investigation of the thermal ring-opening support the experimental
data. Solvating of R+, X- ions in Transition State could explain the trend.

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