Synthesis and characterization of a ruthenium nitrosyl and of sensitysing complexes bearing quinolinic ligands in their coordination sphere

• Grant number: 08/00610-5
• Support type: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): May 01, 2008
• Effective date (End): April 30, 2010
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Inorganic Chemistry
• Principal researcher: Sofia Nikolaou
• Grantee: Renata Lopes Rodrigues
• Home Institution: Faculdade de Ciências Farmacêuticas de Ribeirão Preto (FCFRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil

Abstract

In this project, it is intended to synthesize and to characterize a new ruthenium nitrosyl complex, cis-[Ru(biq)2(py)(NO)](PF6)3, where biq = 2,2´-biquinoline e py= pyridine and other two ruthenium complexes, [Ru(biq)2Cl2] and [Ru(biq)3](PF6)2 (whose synthetic route has already been described in literature), aiming to use them as photosensityzing agents to delivery NO from the ruthenium nitrosyl. The potential use of this type of complexes as delivering agents of reactive species of nitric oxide (ERONs) and their ability to act as tumoricid and in PDT justify this propose. These functions can be achieved by means of the sensitisation of the nitrosyl compound by irradiating the sensitizing compounds. The choise of the biquinoline ligand completes the series originally proposed in a previous project (FAPESP 05/01069-8) and is due to the fact that this kind of ligands have a more pronunced influence on the properties of the nitrosyl complex than the pyridinic ligands (this result was observed in the work of Elisa C. Fornari - PIBIC). The idea of using the complexes [Ru(biq)2Cl2] and [Ru(biq)3](PF6)2 as photosensityzing arises from the fact that both compounds show relatively intense absorption bands in the visible region of the spectrum and, the 2,2´-biquinoline ligand in the complexes coordination sphere represents recognition sites of hydrophobic interactions, which might promote such an interaction between the sensityzer and the nitrosyl ruthenium compound. The complex cis-[Ru(biq)2(py)(NO)](PF6)3 will be characterized by means of UV-visible, infra-red and NMR spectroscopies, mass spectrometry and cyclic voltammetry. Finally, The photolabilization of the NO from the nytrosil complex through the irradiation of the sensitysing agents will be studied and the NO will be detected by means of amperometric experiments.