Monte Carlo-like peaks assignment using a Time-Resolved in-situ NMR approach for complex reaction monitoring: a case study of the photodegradation of Retinyl Acetate

Abstract

Photoactive molecules are of central interest due to their roles in light-matter interaction and in biological systems, and their applications in technology and medicine. Many important photoactive molecules undergo photodegradation, which is a complex, multi-path process involving many molecular species. One compelling case of photodecomposition involves retinyl acetate, which is necessary for vision processes. Here, we demonstrate a comprehensive approach in which the informativity of NMR can be harnessed for the in-depth investigation of the way in which photodegradation proceeds via a combination of two approaches: the interleaved Time-Resolved Non-Uniform Sampling and Time-Resolved Diffusion NMR.Specifically, the mass evolution, which was estimated from the first approach, was compared with the mass calculated from the diffusion coefficient estimated from the second approach, and the correlation between them was identified, enabling NMR signal assignment. This comparison is used for the Monte Carlo-like assignment, in which a vast library of potential reactants is scanned to determine the proper assignment. The presented approach is general-purpose and can be easily implemented for the investigation of many important photodegradation processes