Accurate Standard Hydrogen Electrode Potential and Applications to the Redox Potentials of Vitamin C and NAD/NADH
Accurate Standard Hydrogen Electrode Potential and Applications to the Redox Potentials of Vitamin C and NAD/NADH
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DOI：
10.1021/jp508308y
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发表时间：
2015-01-15
影响因子：
2.9
通讯作者：
Shigeta, Yasuteru
中科院分区：
文献类型：
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作者：
Matsui, Toru;Kitagawa, Yasutaka;Shigeta, Yasuteru
我们从醇分子的实验pK(A)值计算了水相标准氢电极(SHE)电势和质子的吉布斯能。根据金标准CCSD(T)/Aug-cc-pVTZ能级计算，我们估计SHE电势为4.48V，与IUPAC推荐的实验值4.44V非常接近。当应用同样复制金标准能级计算的Gauss3(G3)方法时，我们计算了维生素系列的各种pK(A)值和氧化还原电势。对于维生素C，我们支持+0.35V的实验结果，并预测d-抗坏血酸的pKa值为3.7-3.9。利用烟酰胺腺嘌呤二核苷酸(NAD)的模型分子，根据质子亲和势和氧化还原电势，重现了氧化还原电势，并确定了质子/电子加成的顺序。
We computationally evaluated the standard hydrogen electrode (SHE) potential in aqueous phase and the Gibbs energy of a proton from the experimental pK(a) values of alcohol molecules. From the golden standard CCSD(T)/aug-cc-pVTZ level calculation, we estimated the SHE potential as 4.48 V, which is very close to the IUPAC-recommended experimental value of 4.44 V. As applications to the Gaussian-3 (G3) methods, which also reproduce the golden standard level calculations, we computed various pK(a) values and redox potentials for a vitamin series. For vitamin C, we support the experimental result of +0.35 V and predict the pKa value of d-ascorbic acid to be 3.7-3.9. Using a model molecule for nicotinamide adenine dinucleotide (NAD), we reproduced the redox potential and determined the order of the proton/electron addition, based on both the proton affinity and redox potential.