64939-03-3Relevant academic research and scientific papers
Nitric oxide and nitroxyl formation in the reduction of trans-tetraamminenitrosyltriethylphosphiteruthenium(II) ion
Metzker, Gustavo,Stefaneli, Eliane Vasconcelos,Pereira, José Clayston Melo,Lima, Francisco Das Chagas Alves,Silva, Sebasti?o Claudino Da,Franco, Douglas Wagner
, p. 765 - 769 (2013)
The reduction of trans-[Ru(NO)(NH3)4(P(OEt) 3)]3+ ion was investigated in aqueous medium. Due to the phosphite ligand trans-effect and trans-influence, this complex selectively releases NO or HNO after one or tw
Nitric oxide and nitroxyl products from the reaction of L -cysteine with trans-[RuNO(NH3)4P(OEt)3](PF6)3
Pereira, José Clayston Melo,Souza, Maykon Lima,Franco, Douglas Wagner
, p. 1005 - 1011 (2015/03/04)
The reaction between the trans-[RuNO(NH3)4P(OEt)3](PF6)3 and L-cysteine (RS-) was studied over a pH range of 2.0-7.4. In this reaction, the concentrations of NO and HNO produced varied as a function of the pH of the solution. The first step of this reaction proceeded quickly [k1 = (3.5 ± 0.3) × 103 M-1 s-1, pH = 3.5, 25 C] and resulted in the formation of trans-[Ru(NH3)4P(OEt)3N(O)SR]2+, which dissociated to yield trans-[Ru(NH3)4P(OEt)3NO·]2+ and RS·. However, trans-[Ru(NH3)4P(OEt)3N(O)SR]n-1 can react with a second L-cysteine, yielding trans-[Ru(NH3)4P(OEt)3N(O)(SR)2]+ [k2 = (3.6 ± 0.1) M-1 s-1, pH = 3.5, 25 C]. Therefore, the trans-[Ru(NH3)4P(OEt)3NO·]2+ species released NO and the trans-[Ru(NH3)4P(OEt)3N(O)(SR)2]n-2 species released HNO.
Ruthenium tetraammines as a model of nitric oxide donor compounds
Toledo, Jose Carlos,Silva, Hildo A. S.,Scarpellini, Marciela,Mori, Vania,Camargo, Ademir J.,Bertotti, Mauro,Franco, Douglas W.
, p. 1879 - 1885 (2007/10/03)
The nitric oxide liberation from trans-[Ru(NH3) 4(L)(NO)]3+ (where L = py, 4-pic, isn, nic, L-His, 4-Clpy, imN) after one-electron-chemical or electrochemical reduction was investigated through spectroscopic and electrochemical techniques, reaction-product analysis and quantum-mechanic calculations. These complexes can be formally viewed as a RuII(NO+) species and the reduction site is located on the NO ligand. The E° for the trans-[RuII(NH3) 4(L)(NO+)]3+/trans-[RuII(NH 3)4(L)(NO)]2+ redox process ranges from 0.072 V vs. NHE (nic) to -0.118 V vs. NHE (imN). The specific rate constants for NO dissociation from trans-[RuII(NH3)4(L)(NO)] 2+, evaluated through double-step chronoamperometry, range from 0.025 s-1 (nic) to 0.160 s-1 (ImN) at 25 °C. The [Ru IINO+/ RuIINO°] redox potential and the specific rate constant (k-NO), key steps for designing nitrosyl complexes as NO-donor drug prototypes, proved to be controlled by a judicious choice of the ligand (L) trans to NO. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004.
Reactivity of Radicals Generated on Irradiation of trans-[Ru(NH 3)4(NO2)P(OEt)3](PF6)
Carlos, Rose Maria,Rodrigues Cardoso, Daniel,Castellano, Eduardo Ernesto,Osti, Renata Zachi,Camargo, Ademir Joao,Macedo, Luis Guilherme,Franco, Douglas Wagner
, p. 2546 - 2555 (2007/10/03)
The electronic absorption spectrum of trans-[Ru(NH3) 4(NO2)(P(OEt)3]+ in aqueous solution is characterized by a strong absorption band at 334 nm (λ max = 1800 mol-1 L cm-1). On the basis of quantum mechanics calculations, this band has been assigned to a MLCT transition from the metal to the nitro ligand. Molecular orbital calculations also predict an LF transition at 406 nm, which is obscured by the intense MLCT transition. When trans-[Ru(NH3)4(NO 2)(P(OEt)3]+ in acetonitrile is irradiated with a 355 nm pulsed laser light, the absorption features are gradually shifted to represent those of the solventocomplex trans-[Ru(NH3) 4(solv)(P(OEt)3]2+ (λmax = 316 nm, ε = 650 mol-1 L cm-1), which was also detected by 31P NMR spectroscopy. The net photoreaction under these conditions is a photoaquation of trans-[Ru(NH3)4-(NO 2)(P(OEt)3]+, although, after photolysis, the presence of the nitric oxide was detected by differential pulse polarography. In phosphate buffer pH 9.0, after 15 min of photolysis, a thermal reaction resulted in the formation of a hydroxyl radical and a small amount of a paramagnetic species as detected by EPR spectroscopy. In the presence of trans-[Ru(NH3)4(solv)P(OEt)3]2+, the hydroxyl radical initiated a chain reaction. On the basis of spectroscopic and electrochemical data, the role of the radicals produced is analyzed and a reaction sequence consistent with the experimental results is proposed. The 355 nm laser photolysis of trans-[Ru(NH3)4(NO 2)(P(OEt)3]+ in phosphate buffer pH 7.4 also gives nitric oxide, which is readily trapped by ferrihemeproteins (myoglobin, hemoglobin, and cytochrome C), giving rise to the formation of their nitrosylhemeproteins(II), (NO)Fe(II)hem.
