Resonance enhanced multiphoton ionization studies of di-ortho-methoxy methylcinnamate, a cinnamate-based UV-B filter.

Cinnamate derivatives are considered promising starting points for novel UV filters, using judiciously chosen substitutions on this scaffold to achieve a rational optimization of their properties. Here, we employ electron donating substituents to induce changes in the electronic density distribution of this scaffold and position them such that steric interactions are modulated. Applying high-resolution laser spectroscopic techniques on supersonically cooled compounds in combination with quantum chemical calculations has enabled us to obtain a fundamental understanding of how the electronic structure of ground and electronically excited states as well as their dynamics are affected by such substitutions.