Control of Electron Transfer through Molecular WireBased on Molecular Dipole Engineering

1.12残基螺旋肽通过竖直方向的N端固定在金上。STM观察发现，在-1.3 V的偏置下可以识别出明亮的图像，但在1.5 V的偏置下就消失了。其亮度的变化是由于螺旋偶极矩与电场相互作用引起的3 <10>螺旋与1螺旋之间的螺旋相互转化所致。合成了C端有冠醚单元的2.25残基螺旋肽，并在Ph(NO_3)_2水溶液中制备了单层螺旋肽。Pb2+离子与冠醚形成配合物，并成功转移到金上。用H_2S处理膜后，形成了二维的PbS网络。膜的厚度为2.4Å，具有较宽的带隙，具有半导体性质。3.18残基螺旋肽在C端具有二茂铁单元，其自组装单层在金表面形成。用计时电流法测定了长时间内的电子转移反应，得到了螺旋肽的转移速率。在电子转移反应中，多肽与金之间的界面被认为是决定速率的步骤之一。4.16将残基螺旋肽垂直定向固定在金上，用STS测量了分子电导。利用Simons模型分析了I-V曲线，确定了电子转移的衰减系数为0.75Å^<-1>。5.16合成了C端含有n -乙基咔唑基的残基螺旋肽，并在金表面制备了自组装单层。研究了C端羧基电离对螺旋肽电子传递的影响。分子体系表明，光电流通过改变溶液的pH值而被切换。少

1.12-Residue helical peptides were immobilized on gold via N terminal with vertical orientation. STM observation revealed that bright images were identified under bias of -1.3 V, but they disappeared upon applying bias of 1.5 V. The change of the brightness is due to the helix interconversion between 3_<10> helix and a helix, which was induced by interaction of the helical dipole moment with the electric field applied to the helical peptide.2.25-Residue helical peptide with a crown ether unit at C terminal was synthesized, and the monolayer was prepared on aqueous solution of Ph(NO_3)_2. Pb2+ ions formed complex with the crown ether units, and the monolayer was successfully transferred on gold. After treating the membrane with H_2S, 2-dimensional network of PbS was formed. The thickness of the membrane was 2.4Å showing a wide band gap with a semiconductor property.3.18-Residue helical peptides with a ferrocene unit at C terminal were synthesized, and their self-assembled monolayers wer … More e formed on gold. The electron transfer reactions in a long rage were evaluated by chronoamperometry to obtain the transfer rates through helical peptides. The interface between the peptide and gold is considered to be one of the rate-determining steps in the electron transfer reaction.4.16-Residue helical peptides were immobilized on gold with vertical orientation, and the molecular conductance was determined by STS measurements. The I-V curve was analyzed by Simons model, and the attenuation coefficient of the electron transfer was determined to be 0.75Å^<-1>. The helical peptide with a ferrocene unit showed rectification in the I-V curve.5.16-Residue helical peptides with an N-ethyl carbazolyl group at C terminal were synthesized, and their self-assembled monolayers were prepared on gold. The effect of ionization of the C terminal carboxyl group on the electron transfer through the helical peptide was studied. The molecular system demonstrated that the photocurrent was switched by changing the pH of the solution. Less