Studies of excited state dynamics and DNA photocleavage of a photosensitizer coordination complex with an intercalator ligand

• Grant number: 22/08085-4
• Support Opportunities: Scholarships abroad - Research Internship - Master's degree
• Start date: November 01, 2022
• End date: January 31, 2023
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Inorganic Chemistry
• Principal Investigator: Sofia Nikolaou
• Grantee: Renan Ribeiro Bertoloni
• Supervisor: Claudia Turro
• Host Institution: Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto (FFCLRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil
• Institution abroad: Ohio State University, United States
• Associated to the scholarship: 20/15607-1 - Synthesis, characterization and biological properties of a photosensitizing ruthenium mononuclear complex with a bulky ligand and a DNA intercalator with photoinduced release of NO, BP.MS

Abstract

This project proposes a study of interesting properties of the complex [Ru(tpy)(dppz)(H2O)](PF6)2 compared to its precursor [Ru(tpy)(dppz)Cl]PF6, both synthesized and characterized within the scope of the Brazilian Master research project of the BEPE candidate. As both complexes fit into the category of ruthenium-polypyridines, they present interesting photochemical and photophysical properties and, due to this, one of the proposed studies is the dynamics of excited states to investigate the lifetime of these states, allowing the prediction of their potential as photosensitizers, especially for metallopharmaceuticals. Another study to be carried out is the ability of these complexes to perform DNA photocleavage, that is, the ability of the complex to selectively cause DNA damage when irradiated with electromagnetic radiation. With this in mind, one of the ligands used, as observed in the molecular formula, is dppz (dipyrido-[3,2-a:2',3'-c]-phenazine), which was idealized in the structure due to its ability to intercalate with the DNA, causing the complex to reversibly bind to the DNA so that it can carry out the desired effects. The study will be carried out in the laboratory of Dr. Claudia Turro (The Ohio State University), who has already made several partnerships with Dr. Sofia Nikolaou, and who has experience in this type of study with coordination complexes (involving ruthenium and rhenium) that also have dppz in their structure. (AU)