Determination of a thermal E/Z isomerization barrier of first generation molecular motors is reported. Stable (E)-1a directly converts to stable (Z)-1c without photochemical E/Z isomerization. The activation Gibbs energy of the isomerization was determined to be 123 kJ mol-1 by circular dichroism spectral changes. Density functional theory calculations show that (Z)-1c is ∼11.4 kJ mol-1 more stable than (E)-1a.
ASJC Scopus subject areas
- Organic Chemistry