Photochemical reactions of thiols with organic nitrates — Oxygen atom transfer via a thionitrate

Clarke, Jennifer L.; Kastrati, Irida; Johnston, Linda J.; Thatcher, Gregory R. J.
April 2006
Canadian Journal of Chemistry;Apr2006, Vol. 84 Issue 4, p709
Academic Journal
Nitroglycerin is an organic nitrate that has been used in the clinical treatment of angina for 130 years, yet important details of its mechanism of action remain unanswered. The biological activity of nitrates suggests that they are bioactivated to NO via a three-electron reduction. The involvement of free or bound protein thiols in this reduction has often been proposed. To examine the involvement of thiyl radicals in such a process, the photochemical generation of benzenethiyl radical from thiol and disulfide precursors was studied in the presence of isopropyl nitrate. Analysis of reaction products and kinetics led to the conclusion that photolysis of the nitrate to NO2 dominated the observed photochemistry. Formation of sulfonothioate and NO as products, and trapping of NO2 by 4-chlorophenol, indicated a mechanism involving oxygen atom transfer from N to S via a thionitrate intermediate. The results of the study did not indicate a rapid reaction between thiyl radical and organic nitrate. Despite weak nitrate absorption of light >300 nm and a relatively high BDE for homolysis to give NO2, the photochemistry under thiyl-generating conditions was driven by nitrate photolysis to NO2. A novel nitrate, containing a phenyl disulfanyl group linked to nitrate groups, did not undergo photolysis to NO2 or generate sulfonothioate, but did yield NO. These observations suggest that reaction between thiyl radicals and nitrates leading to NO release is a viable pathway, but it is subservient to other competing reactions, such as photolysis, in the case of IPN, and reaction with thiolate, in the case of the novel nitrate.


Related Articles

  • Spatial and electronic structure and 35Cl NQR parameters of ethyl(trichlorogermyl) propionate according to Ab initio calculations. Feshin, V. P.; Feshina, E. V. // Russian Journal of General Chemistry;Oct2013, Vol. 83 Issue 10, p1883 

    Two stable structures of ethyl(trichlorogermyl) propionate have been studied by RHF/6-31G(d) and MP2/6-31G(d) quantum-chemical caclulation with full geometry optimization. The structure with pentacoordinated Ge atom has been more stable than that with tetracoordinated Ge atom. Based on the...

  • Theoretical study of the structure and optical properties of carbon-doped rutile and anatase titanium oxides. Kamisaka, Hideyuki; Adachi, Takahisa; Yamashita, Koichi // Journal of Chemical Physics;8/22/2005, Vol. 123 Issue 8, p084704 

    The structure and optical properties of carbon-doped titanium oxides, TiO2, in the rutile and anatase forms have been investigated theoretically from first principles. Two possible doping sites were studied, carbon at an oxygen site (anion doping) and carbon at a titanium site (cation doping)....

  • Cluster-enhanced X–O2 photochemistry (X=CH3I, C3H6, C6H12, and Xe). Baklanov, Alexey V.; Bogdanchikov, Georgii A.; Vidma, Konstantin V.; Chestakov, Dmitri A.; Parker, David H. // Journal of Chemical Physics;3/28/2007, Vol. 126 Issue 12, p124316 

    The effect of a local environment on the photodissociation of molecular oxygen is investigated in the van der Waals complex X–O2 (X=CH3I, C3H6, C6H12, and Xe). A single laser operating at wavelengths around 226 nm is used for both photodissociation of the van der Waals complex and...

  • Measurement of the rate coefficient for collisional removal of O2(X 3Σg-,Ï…=1) by O(3P). Kalogerakis, Konstantinos S.; Copeland, Richard A.; Slanger, Tom G. // Journal of Chemical Physics;11/15/2005, Vol. 123 Issue 19, p194303 

    We report a laboratory measurement of the rate coefficient for the collisional removal of O2(X3Σg-,υ=1) by O(3P) atoms. In the experiments, 266-nm laser light photodissociates ozone in a mixture of molecular oxygen and ozone. The photolysis step produces vibrationally excited O2(a1Δg)...

  • Effects of samarium dopant on photocatalytic activity of TiO2 nanocrystallite for methylene blue degradation. Qi Xiao; Zhichun Si; Jiang Zhang; Chong Xiao; Zhiming Yu; Guanzhou Qiu // Journal of Materials Science;Nov2007, Vol. 42 Issue 22, p9194 

    Sm3+-doped TiO2 nanocrystalline was synthesized by a sol–gel auto-combustion method and characterized by X-ray diffraction, Brunauer-Emmett-Teller method (BET), UV–vis diffuse reflectance spectroscopy (DRS), and also photoluminescence (PL) emission spectroscopy. The photocatalytic...

  • Influence of Zinc Ions on the Geminal and Bimolecular Stages of the Horse-Myoglobin Oxygenation. Lepeshkevich, S. V.; Poznyak, A. L.; Dzhagarov, B. M. // Journal of Applied Spectroscopy;Sep2005, Vol. 72 Issue 5, p735 

    The kinetics of nanosecond geminal recombination and bimolar association of molecular oxygen with the horse-heart myoglobin has been investigated by laser flash photolysis. The influence of Zn(II) ions on the dioxygenation and rebonding of myoglobin to a ligand has been considered. The kinetics...

  • The role of cluster energy nonaccommodation in atmospheric sulfuric acid nucleation. Kurtén, Theo; Kuang, Chongai; Gómez, Pedro; McMurry, Peter H.; Vehkamäki, Hanna; Ortega, Ismael; Noppel, Madis; Kulmala, Markku // Journal of Chemical Physics;1/14/2010, Vol. 132 Issue 2, p024304 

    We discuss the possible role of energy nonaccommodation (monomer-cluster collisions that do not result in stable product formation due to liberated excess energy) in atmospheric nucleation processes involving sulfuric acid. Qualitative estimates of the role of nonaccommodation are computed using...

  • Kinetic Regimes of Developed Chain Combustion. Azatyan, V. V.; Bolod'yan, I. A.; Kopylov, S. N.; Rubtsov, N. M.; Shebeko, Yu. N. // Combustion, Explosion, & Shock Waves;May/Jun2003, Vol. 39 Issue 3, p354 

    It is shown that chain thermal explosion is an inherent property of chain branching combustion that is due to simultaneous action of a chain avalanche and self‐heating, which under certain conditions also becomes a progressively accelerating process. An attempt to deny this phenomenon is...

  • Radiationless decay of excited states of tetrahydrocannabinol through the S1– S0 (conical) intersection. Halász, Gábor J.; Sobolewski, Andrzej L.; Vibók, Ágnes // Theoretical Chemistry Accounts: Theory, Computation, & Modeling;Mar2010, Vol. 125 Issue 3-6, p503 

    The ground and electronically excited singlet states of tetrahydrocannabinol have been studied theoretically using density functional and time-dependent density functional methods. The vertical excitation energies, the equilibrium geometries as well as the adiabatic excitation energies have been...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics