Photoisomerization of octyl methoxycinnamate

The octyl-p-methoxy-trans-cinnamate (E-OMC) was exposed to sunlight to induce the E to Z transformation. Octyl-p-methoxy-cis-cinnamate (Z-OMC) was then purified from the mixture of the E- and the Z-OMC using C-18-semi-preparative HPLC. The UV absorption of the Z configuration at various concentrations in various solvents was measured. Molar absorption coefficient of the compound was then calculated. By using the obtained molar absorption coefficient of Z-OMC and of E-OMC, E to Z photoisomerization of octyl methoxycinnamate (OMC) in various solvents at various concentrations could be monitored by C-18 HPLC using UV detector. The result indicates that equilibrium of photoisomerization depends upon concentration and polarity of the solvent used.