Astaxanthin interacting with metal clusters: free radical scavenger and photovoltaic materials

Abstract

This investigation mainly intends to study the interaction of ASTA with metal clusters of up to ten atoms. Copper, silver, and gold atoms are used in this analysis. Lambda maximum values, electron donor acceptor capacity (to see the antiradical properties of these compounds), and the HOMO–LUMO gaps (to analyze the potential application of these molecules as materials for solar cells) are reported. None of these properties is linearly dependent on the number of metal atoms in the cluster. Contrarily, there is an even–odd oscillation. The bond of metal atoms and clusters to ASTA generates products (ASTA-M x ) that are redder in color, concurring with experimental results previously reported for shrimps. The production of redder compounds is confusing for consumers of red food products and could cause a health problem. ASTA-M x molecules are better electron donors and better electron acceptors than ASTA, making them become better free radical scavengers. ASTA-Cu4, ASTA-Cu10, and ASTA-Au7 have low values of the ionization energies and high values of the electron affinity; i.e., there are good electron donors and good electron acceptors. They also have the lowest values (around 2.5 eV) of the HOMO–LUMO gap. These results could be useful for future applications.