共查询到19条相似文献,搜索用时 78 毫秒
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研制分子计算机也许是突破传统半导体电子计算机发展极限的唯一出路。本文简述了最近十年分子计算机的研究进展, 重点讨论了DNA 计算机和生物分子计算机的研究成果, 并对可能为人类提供思考和尝试范本的生物活细胞中蛋白质的各种计算机制的研究给予了充分的关注。引用了43篇文献。 相似文献
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电场作用下分子导线的理论研究 总被引:2,自引:0,他引:2
摘要利用从头计算法分别在HF/6-31G, HF/6-31G*, HF/6-31G**, HF/6-31+G, HF/6-31++G, HF/6-31+G*, HF/6-31+G**, HF/D95+*, B3LYP/6-31G*和B3LYP/6-31+G*水平上计算了5个单体的聚乙炔分子导线, 从几何构型、 SCF能量和分子轨道能级三个方面讨论了外电场对分子导线的影响, 给出了聚乙炔分子导线性质与外电场变化的定量关系. 相似文献
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基于自组装单分子层(SAM)的分子器件的性能取决于分子层的超分子结构. 而混合自组装单分子层是一种简便易行的调控单分子层组成和结构的方法. 将具有整流特性的11-二茂铁基-1-十一烷基硫醇(FUT)和惰性1-十一烷硫醇(C11-SH)通过溶液共混制备了混合单分子层, 并用液态EGaIn作为顶电极研究了SAM器件的性质. C11-SH与FUT分子的比例可以调节器件的整流性能: 随着惰性C11-SH分子比例增高, SAM器件的整流比逐渐降低. 有趣的是, 当惰性C11-SH的比例小于20%时, 器件的整流性能反而随C11-SH的加入而得到了提升. 这是由于少量C11-SH分子减弱了由二茂铁分子的排列缺陷引起的漏电流, 改善了分子器件的稳定性和重现性, 为单分子层器件的性能调控提供了一种简便有效的方法. 相似文献
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Lanka D. Wickramasinghe Dr. Shivnath Mazumder Kenneth K. Kpogo Dr. Richard J. Staples Prof. H. Bernhard Schlegel Prof. Cláudio N. Verani 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(31):10786-10790
Amphiphilic five‐coordinate iron(III) complexes with {N2O2Cl} and {N2O3} coordination spheres are studied to elucidate the roles of electronic structure on the mechanisms for current rectification. The presence of an apical chlorido or phenolato ligand plays a crucial role, and the [FeIII{N2O2Cl}] species supports an asymmetric mechanism while its [FeIII{N2O3}] counterpart seems to allow for unimolecular mechanism. The effects of electron‐donating and electron‐withdrawing substituents in the ligand frameworks are also considered. 相似文献
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The Mechanisms of Rectification in Au|Molecule|Au Devices Based on Langmuir–Blodgett Monolayers of Iron(III) and Copper(II) Surfactants 下载免费PDF全文
Lanka D. Wickramasinghe Dr. Shivnath Mazumder Sunalee Gonawala Meeghage Madusanka Perera Habib Baydoun Bishnu Thapa Li Li Lingxiao Xie Prof. Guangzhao Mao Prof. Zhixian Zhou Prof. H. Bernhard Schlegel Prof. Cláudio N. Verani 《Angewandte Chemie (International ed. in English)》2014,53(52):14462-14467
Langmuir–Blodgett films of metallosurfactants were used in Au|molecule|Au devices to investigate the mechanisms of current rectification. 相似文献
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Nao Terasaki Dr. Noritaka Yamamoto Dr. Takashi Hiraga Dr. Yoshinori Yamanoi Dr. Tetsu Yonezawa Dr. Hiroshi Nishihara Prof. Tsutomu Ohmori Dr. Makoto Sakai Dr. Masaaki Fujii Prof. Akihiko Tohri Dr. Masako Iwai Dr. Yasunori Inoue Prof. Satoshi Yoneyama Dr. Makoto Minakata Prof. Isao Enami Prof. 《Angewandte Chemie (International ed. in English)》2009,48(9):1585-1587
Plug and play : Photoinduced electron transfer occurs from photoexcited P700 in photosystem I (PSI) to a gold surface (see picture). A novel molecular connector system is used, in which an artificial molecular wire, which is assembled on the gold surface, was plugged into PSI by reconstitution. Analysis of the photoelectron transfer kinetics proved both the output of electrons from PSI and the effectiveness of the molecular wire.
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Richard L. McCreery Prof. 《Chemphyschem》2009,10(14):2387-2391
Electron transport through single molecules or collections of molecules oriented in parallel can occur by several mechanisms, including coherent tunneling, activated transfer between potential wells, various “hopping” modes, etc. Given suitable energy levels and sufficiently long charge transport times, reduction or oxidation with accompanying nuclear reorganization can occur to generate “polarons”, that is, localized redox centers in the molecule or monolayer. Redox events in molecular junctions are amenable to spectroscopic monitoring in working devices, and can have major effects on the electronic behavior of the junction. Several examples are presented, along with a possible application to molecular memory. 相似文献
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《Angewandte Chemie (International ed. in English)》2018,57(22):6696-6700
The distance dependence of electron transfer (ET) is commonly investigated in linear rigid rod‐like compounds, but studies of molecular wires with integrated corners imposing 90° angles are very rare. By using spirobifluorene as a key bridging element and by substituting it at different positions, two isomeric series of donor‐bridge‐acceptor compounds with either nearly linear or angled geometries were obtained. Photoinduced ET in both series is dominated by rapid through‐bond hole hopping across oligofluorene bridges over distances of up to 70 Å. Despite considerable conformational flexibility, direct through‐space and through‐solvent ET is negligible even in the angled series. The independence of the ET rate constant on the total number of fluorene units in the angled series is attributed to a rate‐limiting tunneling step through the spirobifluorene corner. This finding is relevant for multidimensional ET systems and grids in which individual molecular wires are interlinked at 90° angles. 相似文献
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The First Heteropentanuclear Extended Metal‐Atom Chain: [Ni+Ru25+Ni2+Ni2+(tripyridyldiamido)4(NCS)2] 下载免费PDF全文
Dr. Min‐Jie Huang Dr. Shao‐An Hua Dr. Ming‐Dung Fu Dr. Gin‐Chen Huang Prof. Caixia Yin Chih‐Hung Ko Dr. Ching‐Kuo Kuo Chia‐Hung Hsu Dr. Gene‐Hsiang Lee Kuan‐Yi Ho Dr. Chia‐Hsin Wang Prof. Yaw‐Wen Yang Prof. I‐Chia Chen Prof. Shie‐Ming Peng Prof. Chun‐hsien Chen 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(16):4526-4531
This study develops the first heteropentametal extended metal atom chain (EMAC) in which a string of nickel cores is incorporated with a diruthenium unit to tune the molecular properties. Spectroscopic, crystallographic, and magnetic characterizations show the formation of a fully delocalized Ru25+ unit. This [Ru2]‐containing EMAC exhibits single‐molecule conductance four‐fold superior to that of the pentanickel complex and results in features of negative differential resistance (NDR), which are unobserved in analogues of pentanickel and pentaruthenium EMACs. A plausible mechanism for the NDR behavior is proposed for this diruthenium‐modulated EMAC. 相似文献
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Any kind of device or machine requires a substrate, energy, and information signals. If we wish to operate at the nanometer scale, we must use molecules as substrates. Energy- and signal-processing at a molecular level relies on cause/effect relationships between the input supplied and the kind of process obtained. We have classified energy- and signal-processing at the molecular level according to the nature of the input (electronic, photonic, or chemical) and the nature of the obtained effect (electronic, photonic, or chemical process that follows). By coupling the three kinds of inputs with the three types of resulting processes, nine types of molecular-based processes (electronic, photonic, chemionic, electrophotonic, electrochemionic, photoelectronic, photochemionic, chemiophotonic, and chemioelectronic) can be identified. In this concept article, looking at molecular transformations in an unconventional way, we have tried to give a flavor of some of the new features that project the old science of chemistry towards novel achievements. 相似文献
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The electron transport properties of various molecular junctions based on the thiol-ended oligosilane are investigated through density functional theory combined with non-equilibrium Green's function formalism. Our calculations show that oligosilanes doped by the phenyl and-C10H6 groups demonstrate better rectifying effect and their rectification ratios are up to 15.41 and 65.13 for their molecular junctions. The current-voltage(I-V) curves of all the Au/ modified oligosilane/Au systems in this work are illustrated by frontier molecular orbitals, transmission spectra and density of states under zero bias. And their rectifying behaviors are analyzed through transmission spectra. 相似文献