The influence of crown ethers on the rate of intramolecular cation exchange involving the 5,12-dihydrotetracene radical anion

Abstract

The addition of dibenzo-18-crown-6 to the Na⁺–5,12-dihydrotetracene radical-anion ion pair has been found dramatically to reduce the rate of cation migration. The resulting e.s.r. spectra (which exhibit linewidth alternation) have been computer-simulated employing modified Bloch equations. The activation energy for the cation migration process has been found to be 19.3 kJ mol^–1.