Organic anions. Part 6. Thermal and photochemical interconversion of (E,E)- and (E,Z)-diphenylallyl anions
Abstract
Whereas the position of the E,E/E,Z equilibrium for 1,3-diphenylallyl-lithium in tetrahydrofuran is highly photosensitive, the corresponding equilibrium in liquid ammonia appears to be unaffected by light. N.m.r. measurements for the sodium salt in this solvent between –20 and +20 °C yield a ΔH value for the E,E to E,Z conversion of ca. 6.9 ± 1.0 kJ mol–1.