A method to calculate the one-electron reduction potentials for nitroaromatic compounds based on gas-phase quantum mechanics

2010 ◽  
Vol 32 (2) ◽  
pp. 226-239 ◽  
Author(s):  
Kathy L. Phillips ◽  
Stanley I. Sandler ◽  
Pei C. Chiu
Molecules ◽  
2018 ◽  
Vol 23 (9) ◽  
pp. 2129 ◽  
Author(s):  
Amauri Francisco da Silva ◽  
Antonio João da Silva Filho ◽  
Mário Vasconcellos ◽  
Otávio Luís de Santana

Nitroaromatic compounds—adducts of Morita–Baylis–Hillman (MBHA) reaction—have been applied in the treatment of malaria, leishmaniasis, and Chagas disease. The biological activity of these compounds is directly related to chemical reactivity in the environment, chemical structure of the compound, and reduction of the nitro group. Because of the last aspect, electrochemical methods are used to simulate the pharmacological activity of nitroaromatic compounds. In particular, previous studies have shown a correlation between the one-electron reduction potentials in aprotic medium (estimated by cyclic voltammetry) and antileishmanial activities (measured by the IC50) for a series of twelve MBHA. In the present work, two different computational protocols were calibrated to simulate the reduction potentials for this series of molecules with the aim of supporting the molecular modeling of new pharmacological compounds from the prediction of their reduction potentials. The results showed that it was possible to predict the experimental reduction potential for the calibration set with mean absolute errors of less than 25 mV (about 0.6 kcal·mol−1).


1980 ◽  
Vol 590 (2) ◽  
pp. 273-276 ◽  
Author(s):  
John A. Farrington ◽  
Edward J. Land ◽  
A.John Swallow

2020 ◽  
Vol 24 (01n03) ◽  
pp. 90-97 ◽  
Author(s):  
Taro Koide ◽  
Zihan Zhou ◽  
Ning Xu ◽  
Yoshio Yano ◽  
Toshikazu Ono ◽  
...  

The cobalt complexes of meso-aryl substituted porphycenes were synthesized and characterized. The reduction potentials of the complexes were shifted to the positive side depending on the strength of the electron-withdrawing properties of the meso-substituents, while the optical properties, such as the absorption spectra of these complexes, were similar. This suggests that the energy levels of the molecular orbitals of the complexes were changed by the meso-substituents while the gaps of the orbitals were not significantly changed. The one-electron reduction of the complex did not afford the Co(I) species, but the ligand-reduced radical anion, which was characterized by electrospectrochemistry. The generated ligand-reduced species reacted with alkyl halides to form the Co(III)-alkyl complex. As a result, the reduction potential of the electrolytic reaction could be directly controlled by the substituents of the porphycene. The catalytic reaction with trichloromethylbenzene was also performed and it was found that the ratio of the obtained products was changed by the reduction potentials of the catalyst, [Formula: see text]. the cobalt porphycenes.


2005 ◽  
Vol 392 (3) ◽  
pp. 583-587 ◽  
Author(s):  
Chantal Capeillere-Blandin ◽  
Delphine Mathieu ◽  
Daniel Mansuy

We previously showed that one-electron transfer from tetrahydropterins to iron porphyrins is a very general reaction, with formation of an intermediate cation radical similar to the one detected in NO synthase. As a model reaction, the rates of reduction of eight haemoproteins by diMePH4 (6,7-dimethyltetrahydropterin) have been studied and correlated with their one-electron reduction potentials, Em (FeIII/FeII). On the basis of kinetic data analyses, a bimolecular collisional mechanism is proposed for the electron transfer from diMePH4 to ferrihaemoproteins. Haemoproteins with reduction potentials below −160 mV were shown not to be reduced by diMePH4 to the corresponding ferrohaemoproteins. For haemoproteins with reduction potentials more positive than −160 mV, such as chloroperoxidase, cytochrome b5, methaemoglobin and cytochrome c, there was a good correlation between the second-order reduction rate constant and the redox potential, Em (FeIII/FeII):The rate of reduction of cytochrome c by BH4 [(6R)-5,6,7,8-tetrahydrobiopterin] was determined to be similar to that of the reduction of cytochrome c by diMePH4. These results confirm the role of tetrahydropterins as one-electron donors to FeIII porphyrins.


2020 ◽  
Vol 23 ◽  
pp. 231-242
Author(s):  
Hassan RH Elsaidi ◽  
Leonard I Wiebe ◽  
Piyush Kumar

The reduction potentials of bioreductively-activated drugs represent an important design parameter to be accommodated in the course of creating lead compounds and improving the efficacy of older generation drugs.  Reduction potentials are traditionally reported as single–electron reduction potentials, E(1), measured against reference electrodes under strictly defined experimental conditions.  More recently, computational chemists have described redox properties in terms of a molecule’s highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO), in electron volts (eV).  The relative accessibility of HOMO/LUMO data through calculation using today’s computer infrastructure and simplified algorithms make the calculated value (LUMO) attractive in comparison to the accepted but rigorous experimental determination of E(1).  This paper describes the correlations of eV (LUMO) to E(1) for three series of bioreductively–activated benzotriazine di-N-oxides (BTDOs), ring-substituted BTDOs, ring-added BTDOs and a selection of aromatic nitro compounds. The current computational approach is a closed–shell calculation with a single optimization.  Gas phase geometry optimization was followed by a single–point DFT (Density Functional Theory) energy calculation in the gas phase or in the presence of polar solvent.  The resulting DFT–derived LUMO energies (eV) calculated for BTDO analogues in gas phase and in presence of polar solvent (water) exhibited very strong linear correlations with high computational efficiency (r2 = 0.9925) and a very high predictive ability (MAD = 7 mV and RMSD = 9 mV) when compared to reported experimentally determined single–electron reduction potentials.


2015 ◽  
Vol 49 (6) ◽  
pp. 3778-3786 ◽  
Author(s):  
Alexandra J. Salter-Blanc ◽  
Eric J. Bylaska ◽  
Hayley J. Johnston ◽  
Paul G. Tratnyek

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