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A Post-HF Approach to the Sunscreen Octyl Methoxycinnamate

revised on 18.03.2021, 14:17 and posted on 19.03.2021, 07:33 by Ettore Fois, Mario Oriani, gloria tabacchi
Octyl methoxycinnamate (OMC) is a commercial sunscreen with excellent UVB filter properties. However, it is known to undergo a series of photodegradation processes that decrease its effectiveness as UVB filter. In particular, the trans (E) form - which is considered so far the most stable isomer - converts to the cis (Z) form under the effect of light. In this work, by using post-Hartree-Fock approaches (CCSD, CCSD(t) and CCSD+T(CCSD)) on ground state OMC geometries optimized at the MP2 level we show that the cis and trans form of the gas-phase OMC molecule have comparable stability. Our results suggest that the cis form is stabilized by intra-molecular dispersion interactions, leading to a folded, more compact structure than the trans isomer.


Uninsubria FAR2019


Email Address of Submitting Author


University of Insubria



ORCID For Submitting Author


Declaration of Conflict of Interest

NO conflicts of interest

Version Notes

second version submitted to ChemRxiv