Heterogeneous Proton-Coupled Electron Transfer of an Aminoanthraquinone Self-Assembled Monolayer
Heterogeneous Proton-Coupled Electron Transfer of an Aminoanthraquinone Self-Assembled Monolayer
复制标题
DOI：
10.1021/jp807287p
复制
发表时间：
2009-03-26
影响因子：
3.7
通讯作者：
Sutherland, Todd C.
中科院分区：
文献类型：
--
作者：
Abhayawardhana, Anusha D.;Sutherland, Todd C.
利用电化学阻抗谱（EIS）和循环伏安法研究了1 - 氨基蒽醌衍生物（1 - aminoAQ）自组装单分子层（SAMs）的电化学性质。在不同温度和施加电位下的EIS研究结果表明，1 - 铵基AQ的SAMs在0.1 M硫酸中发生质子耦合电子转移（PCET），速率常数为7.4 s⁻¹。对电荷转移反应的变温研究得出，1 - 铵基AQ氧化还原反应的活化能垒较高，为69 kJ·mol⁻¹，这归因于强分子内氢键的断裂；这一结论得到了核磁共振（NMR）和傅里叶变换红外光谱（FTIR）分析以及密度泛函理论（DFT）计算的支持。发现1 - 铵基AQ氧化还原反应的重组能项为2.7 eV，这与还原时较大的溶剂重组和显著的核重排相一致。
Electrochemical properties of self-assembled monolayers (SAMs) of a 1-aminoanthraquinone derivative (1-aminoAQ) were studied using electrochemical impedance spectroscopy (EIS) and cyclic voltammetry. The results of EIS studies at different temperatures and applied potentials established that SAMs of 1-ammoniumAQ undergo proton-coupled electron transfer (PCET) in 0.1 M H2SO4 with a rate constant of 7.4 s(-1). Variable-temperature studies of the charge-transfer reaction gave a high activation barrier of 69 kJ.mol(-1) for the 1-ammoniumAQ redox reaction, which is attributed to cleavage of a strong intramolecular hydrogen bond; this conclusion is supported by NMR and FTIR spectroscopic analyses, as well as DFT calculations. The 1-ammoniumAQ redox reactions were found to have a reorganizational energy term of 2.7 eV, consistent with large solvent reorganization and substantial nuclear rearrangement upon reduction.