Study of the orthometallation of phenanthrolines with trinuclear ruthenium acetates

• Grant number: 21/14279-3
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• Start date: August 01, 2022
• Status: Discontinued
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Inorganic Chemistry
• Principal Investigator: Sofia Nikolaou
• Grantee: Nicolle Azevedo Portela dos Santos
• Host Institution: Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto (FFCLRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil
• Associated scholarship(s): 24/16876-7 - Study of the orthometallation mechanism of phenanthrolines with triruthenium acetates, BE.EP.DD

Abstract

This project aims to study the ortometallation of phenanthrolines with triruthenium acetates, from the precursor [Ru3O(CH3COO)6(isoquinoline)2(CH3OH)]PF6. Therefore, the project aims to synthesize, from this cluster, five novel trinuclear ¼-oxo ruthenium complexes with the general formula [Ru3O(CH3COO)5(iq)2(phen)]PF6 phen= 1,10-phenanthroline (1), 5-chloro-1,10-phenanthroline (2), 5-methyl-1.10 -phenanthroline (3), 1,10-phenanthroline-5,6-dione (4) and dipyridophenazine (5), in addition to performing a kinetic study of the orthometallation reaction. Isoquinoline was chosen once the triruthenium acetates of isoquinoline has shown promising results for anticancer activity. The choice of the ortometallated ligands is based on the properties of the phenanthroline ligand (bidentate, planar, and hydrophobic), on the presence of potentially interesting substituents for biological interactions and properties, and also on the possibility of extending the structure of the 1,10-phenanthroline-5,6-dione ligand, based on its reaction with aromatic diamines and potential to obtain phenazines. The characterization of the complexes will be done through elemental analysis, cyclic voltammetry, electronic absorption spectra in the UV-Vis region and vibrational in the infrared and NMR region. Other complementary techniques, such as mass spectrometry and differential pulse voltammetry can be used if necessary. Interaction studies of the complexes with fs-DNA (salmon sperm DNA) and HSA (human serum albumin) will be carried out in order to infer, at first from chemical experiments, the potential of the complexes for application as metal-based drugs. These experiments will be carried out by spectrophotometric titrations and application of the Stern-Volmer treatment. In both cases (interaction with DNA and HSA), circular dichroism experiments can be performed in a complementary way. In order to evaluate the application of this complexes series, biological studies are proposed aiming to analyze their potential antiallergic/allergenic activity and their cytotoxicity in tumor cell lines. The intention is to carry out the photophysical characterization of the complexes staged abroad, through measurements in steady-state and time-resolved in a fast decay regime on a femtosecond scale. (AU)