A method to calculate the one‐electron reduction potentials for nitroaromatic compounds based on gas‐phase quantum mechanics |
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Authors: | Kathy L Phillips Stanley I Sandler Pei C Chiu |
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Institution: | 1. Department of Chemical Engineering, Center for Molecular and Engineering Thermodynamics, University of Delaware, 150 Academy Street, Newark, Delaware 19716;2. Department of Civil and Environmental Engineering, University of Delaware, DuPont Hall, Newark, Delaware 19716 |
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Abstract: | Nitroaromatic compounds (NACs) are widespread environmental contaminants, and the one‐electron reduction potential (E) is an important parameter used in modeling their environmental fate. We have identified a method that is both accurate and efficient to predict E values for NACs, using gas‐phase quantum mechanics (QM) calculations combined with empirical correlations. First, the adiabatic electron affinity (EA) at 0 K is calculated using the B98/MG3S method, and the predictions are scaled by a factor of 0.802 to account for systematic errors in the density functional calculations. Second, the E values are predicted from a linear correlation between E and EA. Using this method, E values were predicted with a mean absolute deviation from measured values of 0.021 V for the 14 NACs used to obtain the correlation and 0.029 V for six additional NACs. This represents a substantial improvement in accuracy over predictions by other QM methods, which are affected by large errors in solvation or aqueous‐phase calculations for some compounds. © 2010 Wiley Periodicals, Inc. J Comput Chem, 2010. |
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Keywords: | one‐electron reduction potential nitroaromatic compounds electron affinity solvation quantum mechanics |
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