Ali Ghiami Shomami
(University of Udine)
 

Proton transfer is one of the most fundamental reactions in chemistry and biochemistry. It can occur across various phases - gas, liquid (both aqueous and non-aqueous), and solid - as well as in different states, including ground and excited states, either in bulk or at interfaces (e.g., solid/liquid, liquid/liquid). The tendency of a molecule to donate or accept a proton is measured by its acidity or basicity. While there are several experimental techniques to determine these properties, such measurements are not always feasible. In such cases, computational tools serve as powerful complementary - and sometimes alternative - approaches.
This presentation will focus on the computational modeling of acidity and basicity in a range of organic compounds, including drug-like molecules, under various conditions. While calculating ground-state acidities and basicities is relatively straightforward, the challenge intensifies when dealing with excited states. Excited acids or bases often exhibit significantly enhanced acidity or basicity and can function as photocatalysts - promising alternatives to traditional catalysts. We will explore the complexities of modeling excited-state proton transfer reactions, discuss current challenges and possible solutions, and finally suggest strategies for the rational design of next-generation photocatalysts through systematic exploration of chemical space.