Design and Synthesis of New Systems for Photoprotection and Solar Energy Storage stars

Abstract

This PhD. Thesis is focused on the rational design and obtention of new synthetic sunscreens and molecular energy storage systems. In particular, an evaluation of their photophysical and photochemical properties and diverse structural modifications to tune them was done. The thesis is divided in different chapters. Firstly, an overview of the history of photochemistry and a brief explanation of the fundamental basis of photochemistry that will be crucial throughout this memory will be described in Chapter 1. In the second chapter a general description of UV light exposition dangers and effects are explained together with the concerns and action mechanisms of the commercial sunscreens. Moreover, the obtention and properties of natural mycosporines (MAAs) which inspired this thesis are described. In Chapter 4, a computational and synthetic design of MAA analogues is presented. The computational study clarifies the key features for photoprotection revealing a simpler scaffold which retains these skills. The development of a novel and versatile synthetic procedure allows for the synthesis of a series of analogues with proved and efficient photoprotective capabilities. In Chapter 5, it is presented a spectroscopic analysis using femtosecond temporal resolution techniques to understand the relaxation mechanisms. Also, the influence of substitution is explored by computational methods. Chapter 6 shows the preparation and characterization of other three families of UV filters together with a proposal for their deactivation mechanisms. Finally, in Chapter 7 it is described the concept of molecular solar thermal energy storage (MOST) and three distinct types of system are explored. This work mainly focuses on the catalyzed back-conversion reaction and heat release measurements, obtaining a record system and the computational exploration of the ruling mechanisms.