NO Photorelease from a Ruthenium Complex Assisted by Formation of a Supramolecular Dimer

Author(s)

Douglas B. G. Mateus ^[1] ; Ana Paula L. Batista ^[2] ; Renata L. Rodrigues ^[3] ; Sofia Nikolaou ^[4]

Affiliation

^[1] Universidade de São Paulo. Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto. Departamento de Química - Brasil

^[2] Universidade de São Paulo. Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto. Departamento de Química - Brasil

^[3] Universidade de São Paulo. Departamento de Física e Química. Faculdade de Ciências Farmacêuticas de Ribeirão Preto - Brasil

^[4] Universidade de São Paulo. Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto. Departamento de Química - Brasil

• Document type: Journal article
• Source: Journal of the Brazilian Chemical Society; v. 31, n. 11, p. 2319-2330, 2020-10-30.

Abstract

This work presents the NO release from compound [Ru(biq)2(H2O)(NO)](PF6)3 (biq = 2,2’-biquinoline) with visible light irradiation (λirrad = 660 nm), assisted by the low-absorbing photosensitizer [Ru(biq)2Cl2]. The structure of both compounds were characterized by means of ESI-MS (electrospray ionization mass spectrometry). The NO+ stretching, ν(NO) = 1995 cm-1, is atypically shifted to higher energy. This observation, along with the E1/2 = 0.49 V (vs. Ag/AgCl) assigned to the Ru2+/3+ redox pair observed for compound [Ru(biq)2Cl2] and its photoreactivity in solution suggest that the RuII ion, when coordinated to two biquinolines, behaves as a hard Pearson acid. Molecular modelling results confirmed the typical geometry distortion of ruthenium-polypyridine complexes bearing sterically hindered ligands. They also suggest the formation of a supramolecular dimer, assembled by weak interaction between biquinoline ligands from each compound, that is claimed to be responsible for the high efficiency of the NO photorelease bimolecular sensitization. (AU)

• FAPESP's process: 18/18060-3 - Use of inorganic supramolecular structures for the development of functional molecules and controlled release of bioactive species
• Grantee: Sofia Nikolaou
• Support Opportunities: Regular Research Grants