CAJ | 학술논문

利用基于电化学跳跃接触的扫描隧道显微镜裂结法(ECSTM-BJ),通过现场形成金属电极,对以Cu和Ag 为电极的对苯二甲酸单分子结电导进行了测量.研究结果表明：利用该方法对所有数据直接线性统计即可得到很好结果；两种电极下都存在两套高和低电导值,其中以Cu为电极的单分子结电导高低值分别为11.5和4.0 nS,而以Ag为电极的单分子结电导分别为10.3和3.8 nS,高值都约为低值的3倍,且以Cu为电极的单分子结电导要略大于以Ag为电极的电导,可归结于电极和分子的耦合不同造成的.与同样条件下测量得到的烷基链羧酸单分子结电导只存在一套值相比,对苯二甲酸表现出两套电导值,反应了分子内主链对分子结电导的影响.
이용기우전화학도약접촉적소묘수도현미경렬결법(ECSTM-BJ),통과현장형성금속전겁,대이Cu화Ag 위전겁적대분이갑산단분자결전도진행료측량.연구결과표명：이용해방법대소유수거직접선성통계즉가득도흔호결과；량충전겁하도존재량투고화저전도치,기중이Cu위전겁적단분자결전도고저치분별위11.5화4.0 nS,이이Ag위전겁적단분자결전도분별위10.3화3.8 nS,고치도약위저치적3배,차이Cu위전겁적단분자결전도요략대우이Ag위전겁적전도,가귀결우전겁화분자적우합불동조성적.여동양조건하측량득도적완기련최산단분자결전도지존재일투치상비,대분이갑산표현출량투전도치,반응료분자내주련대분자결전도적영향.
The single-molecule junction conductance of terephthalic acid binding to Cu and Ag electrodes was measured by an electrochemical jump-to-contact scanning tunneling microscopy break junction (ECSTM-BJ) approach. The Cu and Ag electrodes were formed in-situ, via electrodeposition from a solution. The conductance histograms of the single-molecule junctions formed via the binding of terephthalic acid to the Cu and Ag electrodes showed a well-defined shape, in the absence of any data selection. The single-molecule junction conductance values for the terephthalic acid binding to the Cu electrode were 11.5 nS (high conductance) and 4 nS (low conductance), while the high and low conductance values for the Ag electrode were 10.3 and 3.8 nS, respectively. The high conductance values were typical y approximately three times larger than the low conductance values, for both the Cu and the Ag electrodes. The conductance (G) value for the terephthalic acid fol owed the order of GCu>GAg, which indicated the different electronic coupling efficiencies between the molecule and electrodes. In contrast with the single set conductance value measured for alkanedicarboxylic acid using the same approach, two set conductance values were found for the terephthalic acid junctions with the Cu and Ag electrodes. These results illustrated the important role of the backbone of the chain in conductance measurements. The present work demonstrated the influence of the electrode and the molecular structure on the single-molecule junction conductance.