分子逻辑器件研究进展

分子器件具有尺寸小、设计合成可控、存储量大、反应速度快、人工智能等诸多优点,是当今化学、物理和材料等领域研究最为重要的一个交叉领域.综述了近些年来分子逻辑器件领域的研究进展.介绍了各种类型的分子逻辑门、半(加)减法器、分子逻辑线路以及DNA分子和固态分子计算.最后提出了分子器件存在的问题并展望了其应用前景.     

茂铁类单分子结电子传输性质的研究进展

分子导线是构成分子器件的关键部分,它的发展有望解决未来将要面临的电子器件尺寸即将达到理论极限而无法满足人们更高需求的问题.茂铁类分子凭借优秀的物理、化学性质被广泛应用于非线性光学、分子电子学等领域.在过去的十多年里,茂铁基团的引入构建了多种结构新颖的分子导线,为单分子器件的基础研究做出了巨大贡献.然而对于茂铁类分子导线的研究,大多集中于其异茂环取代的衍生物,同茂环取代的衍生物因合成较为困难,并没有受到研究者们的关注.根据分子的结构特征,将茂铁类分子导线分为π共轭型与非π共轭型两大类.以分子的构效关系为主线,对近十几年来茂铁类单分子结电子传输性质方面的工作进行了概括与总结,期望为未来茂铁类分子导线的研究提供借鉴.     

共价双金属配合物在分子导线方面的研究进展

共价双金属配合物因其结构的优越性,在分子器件特别是分子导线的研究方面有广阔的应用前景。分子内电子耦合作用的研究是揭示这类配合物构成的分子导线性能的关键之一。本文介绍了共价双金属配合物的分子内电子耦合作用及此类配合物的结构特点,总结了近年来共价双金属配合物在分子导线领域的研究进展,并对共价双金属配合物的发展前景进行了展望。     

分子整流器

分子尺寸器件是推动分子电子学发展的主力军。本文综述了分子整流器的工作原理，模型分子的设计，研究现状，存在的主要问题和今后的发展方向。     

单分子结的构筑及分子电导性质的测试

分子电子学已成为21世纪研究的热点. 通过将具有特定功能的分子连接在纳米尺度金属电极之间从而构筑包括分子导线、开关、整流器在内的各种分子尺度电子器件, 这引起了科学家们广泛的研究兴趣. 在分子电子学研究中, 构筑金属/分子/金属(MMM)分子结是研究分子器件中电子传输性质的关键. 尽管已经取得了很大的进展, 目前在纳米尺度下构筑稳定可靠的MMM分子结并测试单个分子的电学性质仍然面临很多挑战. 本文着重对单分子电学性质的测试技术和相关理论研究的最新进展以及存在的挑战做了概述.     

卟啉超分子化合物在分子器件中的应用

分子电子器件已成为近年来的一个研究热点，卟啉类化合物因为光敏性好、性能稳定、易于修饰等优点成为分子器件研究的理想模型化合物。本文着重介绍了它在分子器件中的最新应用进展。     

单分子导电性质的研究进展

介绍了测量单个有机分子导电性质的一些进展,包括分子的尺寸效应、官能团效应、分子与电极的接触效应等,以及分子逻辑器件的初步研究.     

自组装分子电子器件

自组装技术是解决有机功能分子与电极连接问题最有希望的技术之一,近-来在构筑分子电子器件中得到了越来越多的应用,成为分子电子学发展的一个重要方向.本文介绍了自组装技术在制备分子器件中的应用.并讨论了自组装分子器件的前景和面临的一些问题.     

分子器件中的光致异构效应

基于光致异构分子构筑单分子光电子器件或分子膜器件,探究器件中分子在光诱导下构型的变化规律,并在单分子水平上探索其异构效应对电荷传输、器件光电性能的影响,对推动有关分子器件的基础应用研究至关重要.本文系统阐述近些年关于光致异构分子器件的研究成果,着重梳理了关于分子器件的制备、电荷传输机理、器件性能调控以及应用等方面的代表...     

纳米器件研究与应用的最新发展

近几年来对纳米器件的研究给各个领域带来了巨大的冲击。文章讨论了纳米器件特别是和信息技术产业密切相关的分子电路的最新进展 ,以及目前对纳米器件的一些主要的应用     

用于设计分子导线和分子开关的双核混价配合物

分子电子器件的研制是近年来的一个热点课题，桥联混价双核配合物是分子导线和分子开关研究的理想模型化合物，本文介绍了桥配体导电性的测量评估方法和分子开关的主要类型，并着重介绍了近年来用于这一领域研究的重要配合物体系。     

多功能二噻吩乙烯光致变色光分子开关材料

光致变色材料是一类在不同波长的光交替照射下,产生两种可进行可逆转换的光致异构体并伴随明显的光物理和光化学性能变化的材料。基于其特殊的光致异构性质,人们已开发出多种光致变色功能材料并将其广泛应用于超高密度光信息存储、分子开关、分子逻辑门、分子导线、光电材料、多光子器件、表面/纳米器件、液晶材料、化学传感、生物成像、自组装、聚集诱导发光、光控生物体系等诸多领域。其中,二噻吩乙烯类化合物因其出色的热稳定性、优良的耐疲劳性、快的响应速率、高的转化率和量子产率以及出色的固相反应活性而成为理想的光致变色材料之一。本文主要围绕近期本研究组研究成果着重介绍近几年二噻吩乙烯类化合物从溶液体系到功能化表面体系的研究进展,探讨当前该领域存在的问题并对其前景和发展方向进行展望。     

原子个数n对碳分子线Cn(n＝3～10)基态结构特性的影响

利用密度泛函B3LYP方法, 在6-311++g**基组水平上对碳分子线Cn(n＝3～10)体系的基态电子结构特性等作了理论计算. 计算结果表明, 当n为奇数时, 碳分子线Cn基态都为单重态, 反之, 当n为偶数时, 三重态为其稳定的基态. 同时在得到碳分子线基态构型的基础上, 对其极化率、电荷分布和能级分布进行了研究, 确定了碳分子线体系最高占据轨道HOMO能量EH, 最低未占据轨道LUMO能量EL与n的关系式, 即EHn－2 < EHn < EHn+2, ELn－2 > ELn > ELn+2. 因而碳分子线Cn(n＝3～10)体系的费米能级会表现出特有的奇偶振荡, 本文也对该现象出现的原因进行了讨论.     

Carbazole‐Based Tetrapodal Anchor Groups for Gold Surfaces: Synthesis and Conductance Properties

As the field of molecular‐scale electronics matures and the prospect of devices incorporating molecular wires becomes more feasible, it is necessary to progress from the simple anchor groups used in fundamental conductance studies to more elaborate anchors designed with device stability in mind. This study presents a series of oligo(phenylene‐ethynylene) wires with one tetrapodal anchor and a phenyl or pyridyl head group. The new anchors are designed to bind strongly to gold surfaces without disrupting the conductance pathway of the wires. Conductive probe atomic force microscopy (cAFM) was used to determine the conductance of self‐assembled monolayers (SAMs) of the wires in Au–SAM–Pt and Au–SAM–graphene junctions, from which the conductance per molecule was derived. For tolane‐type wires, mean conductances per molecule of up to 10^?4.37 G₀ (Pt) and 10^?3.78 G₀ (graphene) were measured, despite limited electronic coupling to the Au electrode, demonstrating the potential of this approach. Computational studies of the surface binding geometry and transport properties rationalise and support the experimental results.     

Self-organized interconnect method for molecular devices

Lack of an appropriate method for wiring molecules that have controlled functions and structures has been a barrier for the development of molecular devices. We developed an interconnect method to program three kinds of component molecules with their own functions and to wire a molecular device in a self-organized manner. By using the interconnect method we developed, we produced conductive wires and optical switching devices and have demonstrated their device functions. Our interconnect method allows us to control various molecular device characteristics by combining the three molecules.     

Energy transfer in single-molecule photonic wires.

Molecular photonics is a new emerging field of research around the premise that it is possible to develop optical devices using single molecules as building blocks. Truly technological impact in the field requires focussed efforts on designing functional molecular devices as well as having access to their photonic properties on an individual basis. In this Minireview we discuss our approach towards the design and single-molecule investigation of one-dimensional multimolecular arrays intended to work as molecular photonic wires. Three different schemes have been explored: a) perylene-based dimer and trimer arrays displaying coherent exciton delocalisation at room temperature; b) DNA-based unidirectional molecular wires containing up to five different chromophores and exhibiting weak excitonic interactions between neighbouring dyes; and c) one-dimensional multichromophoric polymers based on perylene polyisocyanides showing excimerlike emission. As a whole, our single-molecule data show the importance of well-defined close packing of chromophores for obtaining optimal excitonic behaviour at room temperature. Further improvement on (bio)chemical synthesis, together with the use of single-molecule techniques, should lead in the near future to efficient and reliable photonic wires with true device functionality.     

A Water-Gated Organic Thin-Film Transistor for Glyphosate Detection: A Comparative Study with Fluorescence Sensing

This work reports the design of a highly sensitive solid-state sensor device based on a water-gated organic thin-film transistor (WG-OTFT) for the selective detection of herbicide glyphosate (GlyP) in water. A competitive assay among carboxylate-functionalized polythiophene, Cu²⁺, and GlyP was employed as a sensing mechanism. Molecular recognition phenomena and electrical double layer (EDL) (at the polymer/water interface) originated from the field-effect worked cooperatively to amplify the sensitivity for GlyP. The limit of detection of WG-OTFT (0.26 ppm) was lower than that of a fluorescence sensor chip (0.95 ppm) which is the conventional sensing method. In contrast to the previously reported insulated molecular wires to block interchain interactions, molecular aggregates under the field-effect has shown to be effective for amplification of sensitivity through “intra”- and “inter”-molecular wire effects. The opposite strategy in this study could pave the way for fully utilizing the sensing properties of polymer-based solid-state sensor devices.     

Electric field measurement for quantum‐dot cellular automata clocking circuits

Bistable molecules under electric field are being investigated for the concept of quantum‐dot cellular automata (QCA). Different configurations of molecular arrays implement various logic devices and circuits. The electric field emitted from underlying metal wires, which are applied with clock signal, not only enables power gain, but also fulfills pipelining computation. It might be convenient to measure the electric field distribution directly from these metal wires. A pseudo‐quantitative method was developed to map the electric field distribution with electrostatic force microscopy. This method converts the phase signal into the electric field intensity, by which we demonstrated how to use a particular electric field distribution to drive the computation of QCA molecules. Copyright © 2008 John Wiley & Sons, Ltd.     

线型共轭Cx桥联双金属有机化合物

分子电子器件是近年来的一个热门课题。线型共轭Cx桥联双金属有机化合物是分子导线、分子开关等分子电子器件的模型化合物之一。本文介绍了线型共轭Cx桥联双金属有机化合物的结构、合成及光电性质。