How does the acidic milieu interfere in the capability of ruthenium nitrosyl complexes to release nitric oxide?

Author(s)

Orenha, Renato Pereira ^[1] ; Morgon, Nelson Henrique ^[2] ; Contreras-Garcia, Julia ^[3] ; Silva, Graziele Cappato Guerra ^[1] ; Nagurniak, Glaucio Regis ^[4] ; Piotrowski, Mauricio Jeomar ^[4] ; Caramori, Giovanni Finoto ^[5] ; Munoz-Castro, Alvaro ^[6] ; Parreira, Renato Luis Tame ^[1]

Affiliation

^[1] Univ Franca, Nucleo Pesquisas Ciencias Exatas & Tecnol, BR-14404600 Franca, SP - Brazil

^[2] Univ Estadual Campinas, Inst Quim, CP 6154, BR-13083970 Campinas, SP - Brazil

^[3] Sorbonne Univ, CNRS, LCT, F-75005 F Paris - France

^[4] Univ Fed Pelotas, Dept Phys, POB 354, BR-96010900 Pelotas, RS - Brazil

^[5] Univ Fed Santa Catarina, Dept Quim, Campus Univ Trindade, CP 476, BR-88040900 Florianopolis, SC - Brazil

^[6] Univ Autonoma Chile, Lab Quim Inorgan & Mat Mol, Fac Ingn, Llano Subercaceaux 2801, Santiago - Chile

• Document type: Journal article
• Source: NEW JOURNAL OF CHEMISTRY; v. 44, n. 3, p. 773-779, JAN 21 2020.
• Web of Science Citations: 0

Abstract

The nitric oxide (NO) molecule is involved in a large number of biological routes. Thus, there is increasing interest in improving the understanding of the NO release mechanisms. One of the traditional NO release mechanisms involves (i) {[}Ru(NO)(NH3)(5)](3+) + e(-) -> {[}Ru(NO)(NH3)(5)](2+) and (ii) {[}Ru(NO)(NH3)(5)](2+) + H2O -> {[}Ru(H2O)(NH3)(5)](2+) + NO chemical reactions. Another possibility is associated with light irradiation: (iii) {[}Ru(NO)(NH3)(5)](3+) + H2O + h nu -> {[}Ru(H2O)(NH3)(5)](3+) + NO, aided by the Ru(d(pi)) -> pi{*}(NO) electronic transition, which decreases the pi back-donation process in the Ru-NO chemical bond. The influence of the acid environment in which these chemical reactions typically occur experimentally has been explored in (iv) {[}Ru(NO)(NH3)(5)](2+) + H3O+ -> {[}Ru(HNO)(NH3)(5)](3+) + H2O; and (v) {[}Ru(HNO)(NH3)(5)](3+) + H2O -> {[}Ru(H2O)(NH3)(5)](3+) + HNO reactions. Reaction (v), supported by eight explicit water molecules, is the most propitious to occur. The HNO charge obtained from the atomic polar tensor scheme is close to zero. The methods of quantum theory of atoms in molecules and non-covalent interactions reveal that the HNO leaving group interacts with two water molecules through partially covalent or ionic chemical bonds. The HNO -> NO conversion after the release from ruthenium molecules is thermodynamically feasible. The electronic spectrum of the structure {[}Ru(HNO)(NH3)(5)](3+) has, unlike the {[}Ru(NO)(NH3)(5)](3+) molecule, the Ru(d(pi)) -> pi{*}(NO) transition with an appropriate absorbance. Therefore, the proton increases the capability of ruthenium complexes to release nitric oxide after the chemical reduction reaction or the light-supported chemical reaction. (AU)

• FAPESP's process: 11/07623-8 - The use of quantum-mechanical methods to study the bonds and chemical interactions in self-organizing systems with applications in catalysis, medicinal chemistry, electrochromism, energy storage and conversion
• Grantee: Renato Luis Tame Parreira
• Support Opportunities: Research Grants - Young Investigators Grants
• FAPESP's process: 19/00543-0 - How modulate the Ruthenium-NO chemical bond from ligands of different nature?
• Grantee: Graziele Cappato Guerra Silva
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• FAPESP's process: 17/24856-2 - The Mechanism of the Substitution Reaction of the Ligand Nitrosyl by Aqua in Ruthenium Coordination Compounds
• Grantee: Renato Pereira Orenha
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 13/08293-7 - CCES - Center for Computational Engineering and Sciences
• Grantee: Munir Salomao Skaf
• Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC