Mechanism of formation of radical pairs during the photolysis of 2,6-di-tert-butylquinone diazide in single crystals of 2,6-di-tert-butyl-4-methylphenol

Abstract

In the preceding investigations [I, 2], radical pairs (RP) arising during low-temperature photolysis of 2,4-di-tert-butyi-quinone diazide in single crystals of 2,6-di-tertbutyl-4-methyl-phenol (ionol) were studied by the EPR method, whereby the formation of two types of radical pairs was observed with dipole-dipole splitting constants D I = 13.2 and D 2 = 3.9 mT, respectively. The RP l are stable up to room temperature, which made it possible to use these radical pairs as a two-spin probe for measuring the thermal expansion coefficient of the ionol crystal.