Exploring the enhancement of electron tunneling induced by intermolecular interactions on surface of self-assembled monolayer

Atomic Sulfur Formation Mechanism on 3-Mercaptopropanoic Acid Derivative Self-Assembled Monolayers: Understanding the C–S Bond Cleavage

“…Note that there are some similarities in the voltammetric characteristics of the desorption curves described so far. As already reported, the peak potential associated with the thiolate desorption is slightly higher (E p = −0.77 V) for Me-MPA than for MPA, 34 and the charge density of this peak is just less (Q desor = 72 μC cm −2 ) than that found for MPA. Up to now, we can state that the thiolate coverage is comparable to that expected for a regular SAM.…”

“…Jiang et al reported the presence of small amounts of atomic sulfur after derivatization of preformed MPA SAMs on Au surfaces . As already mentioned, the derivatization of carboxylic moieties is of great importance, and MPA is one of the most popular targets. ,− For this reason, in this work we studied the atomic sulfur formation on SAMs of methyl 3-mercapto propanoate (Me-MPA). This is the simplest choice to get the essence and the rationale of the C–S bond breaking when SAMs derived from MPAbut not MPA itselfdo form.…”

Study of the electrostatic repulsion of the carboxylic surface in the diffusion layer by scanning electrochemical microscopy

“…The MPA SAM had low surface coverage and some defects, which was consistent with our previous work. [ 17 ] The defective MPA SAM was beneficial in this work. Because a redox mediator can carry out electron tunneling on the MPA SAM and facilitate electron transfer at the defects, the current response signal can be detected.…”

“…Then, the diffused [Fe(CN) 6 ] 4− was oxidized to [Fe(CN) 6 ] 3− on the MPA SAM electrode, and the regenerated [Fe(CN) 6 ] 3− diffused to the tip electrode and was collected on the tip electrode. [ 17 ] In this way, the SECM positive feedback model was designed in this research. With the increase in pH, a positive shift in the dissociation equilibrium of carboxyl groups (RCOOH RCOO − + H + ) occurred, increasing the electrostatic repulsion and affecting the diffusion layer flux of the initial redox mediator.…”

Electrochemical investigation of the intermolecular hydrogen bond on the surface of self-assembled monolayer

“…前面介绍了探针电极上MPA与二茂铁甲醇之间 图 1 在MPA SAM电极上的分子间氢键可逆组装与解组装 过程示意图 [22] (网络版彩图) [22] (网络版彩图) 图 3 存在分子间氢键情况下二茂铁甲醇的电化学氧化过程示意图(红色峰: 氢键键合二茂铁甲醇的峰; 蓝色峰: 非氢键键合 二茂铁甲醇的峰) [23] (网络版彩图) [29] (网络版彩图) [29] (网络版彩图) 图 8 分子间氢键诱导"长程效应"的机理示意图 [34] Figure 8 Schematic representation of the mechanism of the longrange effect which induced by the intermolecular hydrogen bond [34]. 图 9 探针向不同基底的渐近曲线图.…”