551
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Sumaoka J, Pan F, Nonaka A, Takeuchi O, Shigekawa H, Komiyama M. Direct Attachment of Double-stranded DNA to Gold Surface for Preparation of Nano-structured Devices. CHEM LETT 2004. [DOI: 10.1246/cl.2004.700] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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552
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Zhitenev NB, Erbe A, Bao Z. Single- and multigrain nanojunctions with a self-assembled monolayer of conjugated molecules. PHYSICAL REVIEW LETTERS 2004; 92:186805. [PMID: 15169523 DOI: 10.1103/physrevlett.92.186805] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2003] [Indexed: 05/24/2023]
Abstract
Systematic conductivity measurements in nanoscale junctions containing a self-assembled monolayer of conjugated molecules are reported. Different conductivity mechanisms are identified depending on the granularity of the metal used as a substrate for assembling the monolayer. Unexpectedly, the energy scale controlling the dominant conductance channels is quite low in comparison with the molecular level spacing. In single-grain junctions, the dominant conductance mechanism is hopping with an energy scale of the order of 10-100 meV determined by the nature of the metal contacts. In the case of multigrain junctions, additional tunnel conductance is observed with low-energy Coulomb-blockade features.
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Affiliation(s)
- N B Zhitenev
- Bell Labs, Lucent Technologies, Murray Hill, NJ 07974, USA
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553
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Ishida T, Mizutani W, Liang TT, Azehara H, Miyake K, Sasaki S, Tokumoto H. Conductive probe AFM measurements of conjugated molecular wires. Ann N Y Acad Sci 2004; 1006:164-86. [PMID: 14976017 DOI: 10.1196/annals.1292.011] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The electrical conduction of self-assembled monolayers (SAMs) made from conjugated molecules was measured using conductive probe atomic force microscopy (CP-AFM), with a focus on the molecular structural effect on conduction. First, the electrical conduction of SAMs made from phenylene oligomer SAMs was measured. The resistances through the monolayers increased exponentially with an increase in molecular length and the decay constants of transconductance beta were about 0.45 to 0.61 A(-1) measured at lower bias region. We further investigated the influence of applied load on the resistances. The resistances through terphenyl SAMs increased with an increase in the applied load up to 14 nN. Second, using an insertion technique into insulating alkanethiol SAMs, the electrical conduction of single conjugated terphenyl methanethiol and oligo(para-phenylenevinylene) (OPV) molecules embedded into insulating alkanethiol SAMs were measured. Electrical currents through these single molecules of OPVs were estimated to be larger than those through single terphenyl molecules, suggesting that the OPV structure can increase the electrical conduction of single molecules. Third, apparent negative differential resistance (NDR) was observed at higher bias measurements of SAMs. The appearance of NDR might be related to roughness of SAM surface, because apparent NDR was often observed on rough surfaces. In any case, the tip-molecule contact condition strongly affected carrier transport through metal tip/SAM/metal junction.
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Affiliation(s)
- Takao Ishida
- Institute of Mechanical Systems Engineering, National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki, Japan.
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554
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Nanoscale fabrication of biomolecular layer and its application to biodevices. BIOTECHNOL BIOPROC E 2004. [DOI: 10.1007/bf02932988] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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555
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Stamouli A, Frenken JWM, Oosterkamp TH, Cogdell RJ, Aartsma TJ. The electron conduction of photosynthetic protein complexes embedded in a membrane. FEBS Lett 2004; 560:109-14. [PMID: 14988007 DOI: 10.1016/s0014-5793(04)00080-8] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2003] [Revised: 01/15/2004] [Accepted: 01/19/2004] [Indexed: 11/18/2022]
Abstract
The conductivity of two photosynthetic protein-pigment complexes, a light harvesting 2 complex and a reaction center, was measured with an atomic force microscope capable of performing electrical measurements. Current-voltage measurements were performed on complexes embedded in their natural environment. Embedding the complexes in lipid bilayers made it possible to discuss the different conduction behaviors of the two complexes in light of their atomic structure.
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Affiliation(s)
- A Stamouli
- Department of Biophysics, Kamerlingh Onnes Laboratory, Leiden University, P.O. Box 9504, 2300 RA Leiden, The Netherlands.
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556
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Tulevski GS, Bushey ML, Kosky JL, Ruter SJT, Nuckolls C. Assembling Dimeric π Stacks on Gold Surfaces by Using Three-Dimensional Lock-and-Key Receptors. Angew Chem Int Ed Engl 2004. [DOI: 10.1002/ange.200353476] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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557
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Tulevski GS, Bushey ML, Kosky JL, Ruter SJT, Nuckolls C. Assembling Dimeric π Stacks on Gold Surfaces by Using Three-Dimensional Lock-and-Key Receptors. Angew Chem Int Ed Engl 2004; 43:1836-9. [PMID: 15054788 DOI: 10.1002/anie.200353476] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- George S Tulevski
- Department of Chemistry and The Nanoscience Center, Columbia University, New York, NY 10027, USA
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558
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Selzer Y, Cabassi MA, Mayer TS, Allara DL. Thermally Activated Conduction in Molecular Junctions. J Am Chem Soc 2004; 126:4052-3. [PMID: 15053563 DOI: 10.1021/ja039015y] [Citation(s) in RCA: 136] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We report temperature dependence measurements on the conductance of individual molecular wires. The results show for the first time in a molecular junction the theoretically predicted transition from coherent superexchange tunneling conductance to an activated hopping mechanism as temperature is increased.
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Affiliation(s)
- Yoram Selzer
- Department of Chemistry and the Materials Research Institute, Pennsylvania State University, Pennsylvania, USA.
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559
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Fan FRF, Yao Y, Cai L, Cheng L, Tour JM, Bard AJ. Structure-Dependent Charge Transport and Storage in Self-Assembled Monolayers of Compounds of Interest in Molecular Electronics: Effects of Tip Material, Headgroup, and Surface Concentration. J Am Chem Soc 2004; 126:4035-42. [PMID: 15038757 DOI: 10.1021/ja0359815] [Citation(s) in RCA: 117] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The electrical properties of self-assembled monolayers (SAMs) on a gold surface have been explored to address the relation between the conductance of a molecule and its electronic structure. We probe interfacial electron transfer processes, particularly those involving electroactive groups, of SAMs of thiolates on Au by using shear force-based scanning probe microscopy (SPM) combined with current-voltage (i-V) and current-distance (i-d) measurements. Peak-shaped i-V curves were obtained for the nitro- and amino-based SAMs studied here. Peak-shaped cathodic i-V curves for nitro-based SAMs were observed at negative potentials in both forward and reverse scans and were used to define the threshold tip bias, V(TH), for electric conduction. For a SAM of 2',5'-dinitro-4,4'-bis(phenylethynyl)-1-benzenethiolate, VII, V(TH) was nearly independent of the tip material [Ir, Pt, Ir-Pt (20-80%), Pd, Ni, Au, Ag, In]. For all of the SAMs studied, the current decreased exponentially with increasing distance, d, between tip and substrate. The exponential attenuation factors (beta values) were lower for the nitro-based SAMs studied here, as compared with alkylthiol-based SAMs. Both V(TH) and beta of the nitro-based SAMs also depended strongly on the molecular headgroup on the end benzene ring addressed by the tip. Finally, we confirmed the "memory" effect observed for nitro-based SAMs. For mixed SAMs of VII and hexadecanethiol, I, the fraction of the charge collected in the negative tip bias region that can be read out at a positive tip bias on reverse scan (up to 38%) depended on the film composition and decreased with an increasing fraction of I, suggesting that lateral electron hopping among molecules of VII occurs in the vicinity of the tip.
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Affiliation(s)
- Fu-Ren F Fan
- Department of Chemistry and Biochemistry and Center for Nano- and Molecular Science and Technology, The University of Texas at Austin, Austin, Texas 78712-0165, USA
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560
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de Boer B, Frank MM, Chabal YJ, Jiang W, Garfunkel E, Bao Z. Metallic contact formation for molecular electronics: interactions between vapor-deposited metals and self-assembled monolayers of conjugated mono- and dithiols. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2004; 20:1539-1542. [PMID: 15801409 DOI: 10.1021/la0356349] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
We present grazing-incidence Fourier transform infrared and AFM data of Au, Al, and Ti vapor-deposited onto self-assembled monolayers (SAMs) of conjugated mono- and dithiols. SAMs of 4,4'''-dimercapto-p-quaterphenyl, 4,4"-dimercapto-p-terphenyl, and 4,4'-dimercapto-p-biphenyl have reactive thiols at the SAM/vacuum interface that interact with vapor-deposited Au or Al atoms, preventing metal penetration. Conjugated monothiols lack such metal blocking groups, and metals (Au, Al) can penetrate into their SAMs. Vapor deposition of Ti onto conjugated mono- and dithiol SAMs and onto hexadecanethiol SAMs destroys the monolayers.
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561
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Camillone N. Diffusion-limited thiol adsorption on the gold(111) surface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2004; 20:1199-206. [PMID: 15803697 DOI: 10.1021/la030121n] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
An optical second harmonic generation measurement of the kinetics of self-assembly of a monolayer of thiols on the Au(111) surface reveals a marked dependence of the adsorption rate upon the solution flow rate. The nature of this dependence indicates that at low concentration and low flow rate the monolayer growth is limited by the existence of a Nernst diffusion layer, not by surface reaction rate kinetics.
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Affiliation(s)
- Nicholas Camillone
- Chemistry Department, Brookhaven National Laboratory, Upton, New York 11973, USA.
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562
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Baer R, Seideman T, Ilani S, Neuhauser D. Ab initiostudy of the alternating current impedance of a molecular junction. J Chem Phys 2004; 120:3387-96. [PMID: 15268494 DOI: 10.1063/1.1640611] [Citation(s) in RCA: 111] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The small-bias conductance of the C6 molecule, stretched between two metallic leads, is studied using time-dependent density functional theory within the adiabatic local density approximation. The leads are modeled by jellium slabs, the electronic density and the current density are described on a grid, whereas the core electrons and the highly oscillating valence orbitals are approximated using standard norm-conserving pseudopotentials. The jellium leads are supplemented by a complex absorbing potential that serves to absorb charge reaching the edge of the electrodes and hence mimic irreversible flow into the macroscopic metal. The system is rapidly exposed to a ramp potential directed along the C6 axis, which gives rise to the onset of charge and current oscillations. As time progresses, a fast redistribution of the molecular charge is observed, which translates into a direct current response. Accompanying the dc signal, alternating current fluctuations of charge and currents within the molecule and the metallic leads are observed. These form the complex impedance of the molecule and are especially strong at the plasmon frequency of the leads and the lowest excitation peak of C6. We study the molecular conductance in two limits: the strong coupling limit, where the edge atoms of the chain are submerged in the jellium and the weak coupling case, where the carbon atoms and the leads do not overlap spatially.
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Affiliation(s)
- Roi Baer
- Institute of Chemistry and the Lise Meitner Minerva-Center for Quantum Chemistry, the Hebrew University of Jerusalem, Jerusalem 91904 Israel.
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563
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Seferos DS, Banach DA, Alcantar NA, Israelachvili JN, Bazan GC. α,ω-Bis(thioacetyl)oligophenylenevinylene Chromophores from Thioanisol Precursors. J Org Chem 2004; 69:1110-9. [PMID: 14961659 DOI: 10.1021/jo035664g] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The selective cleavage of arylmethyl thioethers provides a convenient protocol for the synthesis of all-E isomers of alpha, omega-bis(thioacetyl)oligophenyenevinylene molecules (OPVs). The S-methyl group is tolerant of Wittig-type and Heck-type reactions for forming OPV structures and can be converted to the S-acetyl group by treatment with sodium thiomethoxide and acetyl chloride. The thermal conditions of the deprotection/reprotection step concurrently isomerize the conjugated chromophore to the all-E isomer, regardless of the stereochemistry of the starting olefins. This approach is demonstrated for a variety of linear and [2.2]paracyclophane containing OPVs, which have been characterized by electrochemical and spectroscopic techniques. Additionally, these S-acetyl-terminated OPVs self-assemble on gold surfaces. Monolayers containing these molecules were characterized by water contact angle measurements, ellipsometry, and X-ray photoelectron spectroscopy.
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Affiliation(s)
- Dwight S Seferos
- Department of Chemistry and Biochemistry, Institute for Polymers and Organic Solids, University of California, Santa Barbara, California 93106, USA
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564
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Tomfohr J, Sankey OF. Theoretical analysis of electron transport through organic molecules. J Chem Phys 2004; 120:1542-54. [PMID: 15268281 DOI: 10.1063/1.1625911] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We present a theoretical study of electron transport through a variety of organic molecules. The analysis uses the Landauer formalism in combination with complex bandstructure and projected densities of states calculations to reveal the main aspects of coherent electronic transport through alkanes, benzene-dithiol, and phenylene-ethynylene oligomers. We examine the dependence of the current on molecule length, the effects of molecule-molecule interactions from film packing, differences in contact geometry, and the influence of phenyl ring rotation on the conductances of phenylene-ethynylene oligomers such as 1,4-bis-phenylethynyl-benzene.
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Affiliation(s)
- John Tomfohr
- Department of Physics and Astronomy, Arizona State University, Tempe, Arizona 85287, USA
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565
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Nowak AM, McCreery RL. Characterization of Carbon/Nitroazobenzene/Titanium Molecular Electronic Junctions with Photoelectron and Raman Spectroscopy. Anal Chem 2004; 76:1089-97. [PMID: 14961743 DOI: 10.1021/ac034807w] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Molecular junctions consisting of nitroazobenzene (NAB) chemisorbed to a substrate of pyrolyzed photoresist film (PPF) and a top contact of vapor-deposited titanium were examined with Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). The thickness of the NAB layer varied from submonolayer to 4.5 nm, and a thin (1-3 nm) overlayer of Ti was deposited by electron beam deposition. Without Ti, the NAB surface Raman spectrum was sufficiently strong to observe previously unreported modes in the 500-1000-cm(-1) region, and the 1000-1700-cm(-1) region was sufficiently strong to observe the effects of metal deposition. Upon Ti deposition, the intensities of NAB modes associated with the nitro group decreased significantly, and the XPS indicated formation of a Ti-N bond. For the thicker NAB layers (1.9 and 4.5 nm), the intensities of the NO(2) Raman modes partially recovered over a several-day period, but they remain depressed or absent in the submonolayer sample. The results indicate a reaction between condensing Ti atoms and the terminal NO(2) group, probably to form a Ti-nitroso linkage between NAB and Ti. The result is a molecular junction with covalent bonding at both ends in the form of a C-C bond between PPF and NAB and a Ti-N bond to the top contact. The structural implications of the current results are interpreted in the context of recently reported functioning PPF/NAB/Ti molecular electronic junctions. In particular, the reaction between Ti and the nitro group appears to prevent short circuits resulting from incursion of Ti into the NAB layer.
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Affiliation(s)
- Aletha M Nowak
- Department of Chemistry, The Ohio State University, 100 West 18th Avenue, Columbus, OH 43210-1185, USA
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566
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Lee HJ, Park SM. Electrochemistry of Conductive Polymers. 30. Nanoscale Measurements of Doping Distributions and Current−Voltage Characteristics of Electrochemically Deposited Polypyrrole Films. J Phys Chem B 2004. [DOI: 10.1021/jp035766a] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Hyo Joong Lee
- Department of Chemistry and Center for Integrated Molecular Systems, Pohang University of Science and Technology, Pohang, Gyeongbuk 790-784, Korea (Republic of Korea)
| | - Su-Moon Park
- Department of Chemistry and Center for Integrated Molecular Systems, Pohang University of Science and Technology, Pohang, Gyeongbuk 790-784, Korea (Republic of Korea)
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567
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568
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Reimers JR, Bilić A, Cai ZL, Dahlbom M, Lambropoulos NA, Solomon GC, Crossley MJ, Hush NS. Molecular Electronics: From Basic Chemical Principles to Photosynthesis to Steady-State Through-Molecule Conductivity to Computer Architectures. Aust J Chem 2004. [DOI: 10.1071/ch04132] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Molecular electronics offers many possibilities for the development of electronic devices beyond the limit of silicon technology. Its basic ideas and history are reviewed, and a central aspect of the delocalization of electrons across molecules and junctions is examined. Analogies between key processes affecting steady-state through-molecule conduction and equilibrium geometric and spectroscopic properties of paradigm molecules, such as hydrogen, ammonia, benzene, and the Creutz–Taube ion are drawn, and the mechanisms by which control can be exerted over molecular-electronic processes during biological photosynthesis are examined. Ab initio molecular dynamics and simulations of conductivity are then presented for carbon nanotube flanged to gold(111), and device characteristics are calculated for a molecular shift register clocked by two gold electrodes.
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569
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Sek S, Bilewicz R, Slowinski K. Electrochemical wiring of α,ω-alkanedithiol molecules into an electrical circuit. Chem Commun (Camb) 2004:404-5. [PMID: 14765230 DOI: 10.1039/b314815g] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The intrinsic electrical conductivity of alpha, omega-alkanedithiol increases if both ends of the molecule are covalently bonded to metallic contacts.
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Affiliation(s)
- Slawomir Sek
- Department of Chemistry and Biochemistry, California State University-Long Beach, 1250 Bellflower Blvd., Long Beach, CA, USA.
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570
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Haiss W, Nichols RJ, Higgins SJ, Bethell D, Höbenreich H, Schiffrin DJ. Wiring nanoparticles with redox molecules. Faraday Discuss 2004; 125:179-94; discussion 195-219. [PMID: 14750672 DOI: 10.1039/b303214k] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Gold nanoparticles were used to make electrical contact to redox-active organic molecules. Viologen based dithiols were self-assembled from solution on Au(111) for use as tethers to attach nanoparticles to a conducting substrate. The topography and electrical properties of the resulting films were investigated by STM and STS and the orientation of these linkers was investigated by FTIR. Surface coverage increased with increasing reaction time, resulting in a change of film orientation from a flat to a more upright standing conformation. Gold nanoparticles attached to these self-assembled films were characterised by STM. It was possible to isolate a single redox-active molecule in an alkanethiol matrix and by subsequent attachment of a single gold nanoparticle the electrical properties of single wired molecules could be investigated. This method allowed the measurement of the conductivity of single molecules connecting a nanoparticle to the substrate chemically, thus forming stable electrical contacts at both ends.
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Affiliation(s)
- Wolfgang Haiss
- Centre for Nanoscale Science, Chemistry Department, University of Liverpool, Liverpool, UK L69 7ZD
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571
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Kohler S, Camalet S, Strass M, Lehmann J, Ingold GL, Hänggi P. Charge transport through a molecule driven by a high-frequency field. Chem Phys 2004. [DOI: 10.1016/j.chemphys.2003.09.023] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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572
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Greene ME, Kinser CR, Kramer DE, Pingree LSC, Hersam MC. Application of scanning probe microscopy to the characterization and fabrication of hybrid nanomaterials. Microsc Res Tech 2004; 64:415-34. [PMID: 15549695 DOI: 10.1002/jemt.20100] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Scanning probe microscopy (SPM) is a widely used experimental technique for characterizing and fabricating nanostructures on surfaces. In particular, due to its ability to spatially map variations in materials properties with nanometer spatial resolution, SPM is particularly well suited to probe the subcomponents and interfaces of hybrid nanomaterials, i.e., materials that are made up of distinct nanometer scale components with distinguishable properties. In addition, the interaction of the SPM tip with materials can be intentionally tuned such that local surface modification is achieved. In this manner, hybrid nanostructures can also be fabricated on solid substrates using SPM. This report reviews recent developments in the characterization and fabrication of hybrid nanomaterials with SPM. Specific attention is given to nanomaterials that consist of both organic and inorganic components including individual biomolecules mounted on inorganic substrates. SPM techniques that are particularly well suited for characterizing the mechanical and electrical properties of such hybrid systems in atmospheric pressure environments are highlighted, and specific illustrative examples are provided. This review concludes with a brief discussion of the remaining challenges and promising future prospects for this field.
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Affiliation(s)
- Mark E Greene
- Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208-3108, USA
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573
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Davis JJ. Molecular bioelectronics. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2003; 361:2807-2825. [PMID: 14667299 DOI: 10.1098/rsta.2003.1270] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Biological macromolecules have evolved over many millions of years into structures primed, in some cases, for both specific surface recognition and facile, directional electron tunnelling. The redox-active centres of metalloproteins play a central role in photosynthesis and respiration. The processes by which constructive man-made interfaces to these moieties can be generated have advanced greatly during the past two decades or so. Together with recent advances in molecular manipulation, analyses and lithographic fabrication, this knowledge has led to us to the point where bioelectronic devices can be designed and interrogated with good levels of reproducibility.
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Affiliation(s)
- J J Davis
- Inorganic Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QR, UK
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574
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Basch H, Ratner MA. Binding at molecule/gold transport interfaces. I. Geometry and bonding. J Chem Phys 2003. [DOI: 10.1063/1.1613941] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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575
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Kornilovitch P, Bratkovsky A, Williams S. Single-Molecule Designs for Electric Switches and Rectifiers. Ann N Y Acad Sci 2003; 1006:198-211. [PMID: 14976019 DOI: 10.1196/annals.1292.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
A design for molecular rectifiers is proposed. Current rectification is based on the spatial asymmetry of a molecule and requires only one resonant conducting molecular orbital. Rectification is caused by asymmetric coupling of the orbital to the electrodes, which results in asymmetric movement of the two Fermi levels with respect to the orbital under external bias. Results from numerical studies of the family of suggested molecular rectifiers, HS-(CH(2))(n)-C(6)H(4)(CH(2))(m)SH, are presented. Current rectification ratios in excess of 100 are achievable for n = 2 and m > 6. A class of bistable stator-rotor molecules is proposed. The stationary part connects the two electrodes and facilitates electron transport between them. The rotary part, which has a large dipole moment, is attached to an atom of the stator via a single sigma bond. Electrostatic bonds formed between the oxygen atom of the rotor and hydrogen atoms of the stator make the symmetric orientation of the dipole unstable. The rotor has two potential minima with equal energy for rotation about the sigma bond. The dipole can be flipped between the two states by an external electric field. Both rotor-orientation states have asymmetric current-voltage characteristics that are the reverse of each other, so they are distinguishable electrically. Theoretical results on conformation, energy barriers, retention times, switching voltages, and current-voltage characteristics are presented for a particular stator-rotor molecule. Such molecules could be the base for single-molecule switches, reversible diodes, and other molecular electronic devices.
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576
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Kushmerick JJ, Pollack SK, Yang JC, Naciri J, Holt DB, Ratner MA, Shashidhar R. Understanding Charge Transport in Molecular Electronics. Ann N Y Acad Sci 2003; 1006:277-90. [PMID: 14976024 DOI: 10.1196/annals.1292.019] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
For molecular electronics to become a viable technology the factors that control charge transport across a metal-molecule-metal junction need to be elucidated. We use an experimentally simple crossed-wire tunnel junction to interrogate how factors such as metal-molecule coupling, molecular structure, and the choice of metal electrode influence the current-voltage characteristics of a molecular junction.
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Affiliation(s)
- J J Kushmerick
- Center for Bio/Molecular Science and Engineering, Naval Research Laboratory, Washington, DC 20375, USA.
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577
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Anderson NA, Ai X, Chen D, Mohler DL, Lian T. Bridge-Assisted Ultrafast Interfacial Electron Transfer to Nanocrystalline SnO2 Thin Films. J Phys Chem B 2003. [DOI: 10.1021/jp035445z] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Neil A. Anderson
- Department of Chemistry, Emory University, Atlanta, Georgia 30322
| | - Xin Ai
- Department of Chemistry, Emory University, Atlanta, Georgia 30322
| | - Daitao Chen
- Department of Chemistry, Emory University, Atlanta, Georgia 30322
| | - Debra L. Mohler
- Department of Chemistry, Emory University, Atlanta, Georgia 30322
| | - Tianquan Lian
- Department of Chemistry, Emory University, Atlanta, Georgia 30322
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578
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Bonanni B, Alliata D, Bizzarri AR, Cannistraro S. Topological and Electron-Transfer Properties of Yeast Cytochrome c Adsorbed on Bare Gold Electrodes. Chemphyschem 2003; 4:1183-8. [PMID: 14652996 DOI: 10.1002/cphc.200300784] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The redox metalloprotein yeast cytochrome c was directly self-chemisorbed on "bare" gold electrodes through the free sulfur-containing group Cys102. Topological, spectroscopic, and electron transfer properties of the immobilised molecules were investigated by in situ scanning probe microscopy and cyclic voltammetry. Atomic force and scanning tunnelling microscopy revealed individual protein molecules adsorbed on the gold substrate, with no evidence of aggregates. The adsorbed proteins appear to be firmly bound to gold and display dimensions in good agreement with crystallographic data. Cyclic voltammetric analysis showed that up to 84% of the electrode surface is functionalised with electroactive proteins whose measured redox midpoint potential is in good agreement with the formal potential. Our results clearly indicate that this variant of cytochrome c is adsorbed on bare gold electrodes with preservation of morphological properties and redox functionality.
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Affiliation(s)
- Beatrice Bonanni
- Biophysics and Nanoscience Group, INFM, Dipartimento di Scienze Ambientali Università della Tuscia, Largo dell'Università, 01100 Viterbo, Italy
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579
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Dupraz CJ, Beierlein U, Kotthaus JP. Low Temperature Conductance Measurements of Self-Assembled Monolayers of 1,4-Phenylene Diisocyanide. Chemphyschem 2003; 4:1247-52. [PMID: 14653008 DOI: 10.1002/cphc.200300706] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Christian J Dupraz
- Center for NanoScience and Sektion Physik Ludwig-Maximilians-Universität-München Geschwister-Scholl-Platz 1, 80539 München, Germany
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580
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OGAWA T. 単一分子ないしは少数分子の電気特性の研究の最近の展開. ELECTROCHEMISTRY 2003. [DOI: 10.5796/electrochemistry.71.952] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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581
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SAKAGUCHI H. 光と金属探針を用いる単一分子電気計測. ELECTROCHEMISTRY 2003. [DOI: 10.5796/electrochemistry.71.956] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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582
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Burrows BL, Amos AT. Time-dependent currents through small molecules using wide-band and narrow-band approximations. J Chem Phys 2003. [DOI: 10.1063/1.1611172] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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583
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Kitagawa K, Morita T, Kawasaki M, Kimura S. Electric properties of self-assembled monolayers of helical peptides by scanning tunneling spectroscopy. ACTA ACUST UNITED AC 2003. [DOI: 10.1002/pola.10833] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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584
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Leng, Keffer DJ, Cummings PT. Structure and Dynamics of a Benzenedithiol Monolayer on a Au(111) Surface. J Phys Chem B 2003. [DOI: 10.1021/jp034405s] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Leng
- Department of Chemical Engineering, Vanderbilt University, Nashville, Tennessee 37235-1604, Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6110, and Department of Chemical Engineering, The University of Tennessee, Knoxville, Tennessee 37996-2200
| | - David J. Keffer
- Department of Chemical Engineering, Vanderbilt University, Nashville, Tennessee 37235-1604, Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6110, and Department of Chemical Engineering, The University of Tennessee, Knoxville, Tennessee 37996-2200
| | - Peter T. Cummings
- Department of Chemical Engineering, Vanderbilt University, Nashville, Tennessee 37235-1604, Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6110, and Department of Chemical Engineering, The University of Tennessee, Knoxville, Tennessee 37996-2200
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585
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Abstract
Artificial nanostructures, each composed of a copper(II) phthalocyanine (CuPc) molecule bonded to two gold atomic chains with a controlled gap, were assembled on a NiAl(110) surface by manipulation of individual gold atoms and CuPc molecules with a scanning tunneling microscope. The electronic densities of states of these hybrid structures were measured by spatially resolved electronic spectroscopy and systematically tuned by varying the number of gold atoms in the chains one by one. The present approach provides structural images and electronic characterization of the metal-molecule-metal junction, thereby elucidating the nature of the contacts between the molecule and metal in this junction.
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Affiliation(s)
- G V Nazin
- Department of Physics and Astronomy, University of California, Irvine, CA 92697-4575, USA
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586
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Wakamatsu S, Fujii S, Akiba U, Fujihira M. Dependence of tunneling current through a single molecule of phenylene oligomers on the molecular length. Ultramicroscopy 2003; 97:19-26. [PMID: 12801653 DOI: 10.1016/s0304-3991(03)00026-3] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The electrical properties of single phenylene oligomers were studied in terms of the dependence of the tunneling current on the length of the oligomers using self-assembling techniques and scanning tunneling microscopy (STM). It is important to isolate single molecules in an insulating matrix for the measurement of the conductivity of the single molecule. We demonstrate here a novel self-assembled monolayer (SAM) matrix appropriate for isolation of the single molecules. A bicyclo[2.2.2]octane derivative was used for a SAM matrix, in which the single molecules were inserted at molecular lattice defects. The isolated single molecules of phenylene oligomers inserted in the SAM matrix were observed as protrusions in STM topography using a constant current mode. We measured the topographic heights of the molecular protrusions using STM and estimated the decay constant, beta, of the tunneling current through the single phenylene oligomers using a bilayer tunnel junction model.
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Affiliation(s)
- Satoshi Wakamatsu
- Department of Biomolecular Engineering, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama, 226-8501, Japan
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587
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Thermally stimulated transition in tunneling characteristics of molecular junction of tin/octadecanol/tin. Chem Phys Lett 2003. [DOI: 10.1016/j.cplett.2003.09.080] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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588
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Wang CK, Luo Y. Current–voltage characteristics of single molecular junction: Dimensionality of metal contacts. J Chem Phys 2003. [DOI: 10.1063/1.1597197] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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589
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Xu B, Tao NJ. Measurement of single-molecule resistance by repeated formation of molecular junctions. Science 2003; 301:1221-3. [PMID: 12947193 DOI: 10.1126/science.1087481] [Citation(s) in RCA: 1280] [Impact Index Per Article: 61.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The conductance of a single molecule connected to two gold electrodes was determined by repeatedly forming thousands of gold-molecule-gold junctions. Conductance histograms revealed well-defined peaks at integer multiples of a fundamental conductance value, which was used to identify the conductance of a single molecule. The resistances near zero bias were 10.5 +/- 0.5, 51 +/- 5, 630 +/- 50, and 1.3 +/- 0.1 megohms for hexanedithiol, octanedithiol, decanedithiol, and 4,4' bipyridine, respectively. The tunneling decay constant (betaN) for N-alkanedithiols was 1.0 +/- 0.1 per carbon atom and was weakly dependent on the applied bias. The resistance and betaN values are consistent with first-principles calculations.
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Affiliation(s)
- Bingqian Xu
- Department of Electrical Engineering and The Center for Solid State Electronics Research, Arizona State University, Tempe, AZ 85287, USA
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590
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Tunneling conductivity of one- and two-component alkanethiol bilayers in Hg–Hg junctions. J Electroanal Chem (Lausanne) 2003. [DOI: 10.1016/s0022-0728(02)01265-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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591
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Felgenhauer T, Rong HT, Buck M. Electrochemical and exchange studies of self-assembled monolayers of biphenyl based thiols on gold. J Electroanal Chem (Lausanne) 2003. [DOI: 10.1016/s0022-0728(03)00139-6] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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592
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593
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Camalet S, Lehmann J, Kohler S, Hänggi P. Current noise in ac-driven nanoscale conductors. PHYSICAL REVIEW LETTERS 2003; 90:210602. [PMID: 12786543 DOI: 10.1103/physrevlett.90.210602] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2002] [Indexed: 05/24/2023]
Abstract
The theory for current fluctuations in ac-driven transport through nanoscale systems is put forward. By use of a generalized, non-Hermitian Floquet theory we derive novel explicit expressions for the time-averaged current and the zero-frequency component of the power spectrum of current fluctuations. A distinct suppression of both the zero-frequency noise and the dc current occurs for suitably tailored ac fields. The relative level of transport noise, being characterized by a Fano factor, can selectively be manipulated by ac sources; in particular, it exhibits both characteristic maxima and minima near current suppression.
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Affiliation(s)
- Sébastien Camalet
- Institut für Physik, Universität Augsburg, Universitätsstrasse 1, D-86135 Augsburg, Germany
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594
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Abstract
Molecular conductance junctions are structures in which single molecules or small groups of molecules conduct electrical current between two electrodes. In such junctions, the connection between the molecule and the electrodes greatly affects the current-voltage characteristics. Despite several experimental and theoretical advances, including the understanding of simple systems, there is still limited correspondence between experimental and theoretical studies of these systems.
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Affiliation(s)
- Abraham Nitzan
- School of Chemistry, Tel Aviv University, Tel Aviv, 69978, Israel
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595
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Ramachandran GK, Hopson TJ, Rawlett AM, Nagahara LA, Primak A, Lindsay SM. A bond-fluctuation mechanism for stochastic switching in wired molecules. Science 2003; 300:1413-6. [PMID: 12775835 DOI: 10.1126/science.1083825] [Citation(s) in RCA: 370] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Stochastic on-off conductivity switching observed in phenylene-ethynylene oligomers has been explained in terms of changes in ring conformations, or electron localization, or both. We report the observation of stochastic on-off switching in the simplest of wired molecules: octanedithiol, decanedithiol, and dodecanedithiol bonded on an Au(111) surface. Stochastic switching was observed even when a top gold contact was pressed on by a conducting atomic force microscope tip at constant force. The rate of switching increased substantially at 60 degrees C, a temperature at which these films are commonly annealed. Because such switching in alkanethiols is unlikely to be caused by internal molecular electronic changes and cannot be fully accounted for by breaking of the top contact, we argue that the cause is the well-known mobility of molecules tethered to gold via a thiol linkage.
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596
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York RL, Nguyen PT, Slowinski K. Long-range electron transfer through monolayers and bilayers of alkanethiols in electrochemically controlled Hg[bond]neling junctions. J Am Chem Soc 2003; 125:5948-53. [PMID: 12733935 DOI: 10.1021/ja0211353] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The rates of electron tunneling through monolayers and bilayers of alkanethiols self-assembled in a potentiostatically controlled Hg-Hg junction are reported. An alkanethiolate monolayer is formed in situ on one or both Hg drops via oxidative adsorption at the controlled potential. Subsequently, the Hg drops are brought into contact using micromanipulators. The junction formation is instantly followed by the flow of a steady-state tunneling current between the two electrodes. A plot of the logarithm of the tunneling current density vs the total number of carbon atoms in each junction yields identical tunneling coefficients, beta = 1.06 +/- 0.04/-CH(2)- and beta = 1.02 +/- 0.07/-CH(2)-, for monolayers and bilayers of alkanethiols, respectively. Careful examination of the tunneling data indicates that the solvent and ions are ejected from the junction area. The tunneling current recorded for a bilayer of 1-octanethiol or 1-nonanethiol is ca. 2-fold larger than a corresponding tunneling current recorded for monolayers of 1-hexadecanethiol or 1-octadecanethiol, respectively. This result is explained in terms of weak electronic coupling across the noncovalent molecule/electrode interface.
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Affiliation(s)
- Roger L York
- Department of Chemistry and Biochemistry, California State University-Long Beach, 1250 Bellflower Boulevard, Long Beach, California 90840-3903, USA
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597
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Troisi A, Ratner MA, Nitzan A. Vibronic effects in off-resonant molecular wire conduction. J Chem Phys 2003. [DOI: 10.1063/1.1556854] [Citation(s) in RCA: 115] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
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598
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Pleutin S, Grabert H, Ingold GL, Nitzan A. The electrostatic potential profile along a biased molecular wire: A model quantum-mechanical calculation. J Chem Phys 2003. [DOI: 10.1063/1.1539863] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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599
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Smalley JF, Finklea HO, Chidsey CED, Linford MR, Creager SE, Ferraris JP, Chalfant K, Zawodzinsk T, Feldberg SW, Newton MD. Heterogeneous electron-transfer kinetics for ruthenium and ferrocene redox moieties through alkanethiol monolayers on gold. J Am Chem Soc 2003; 125:2004-13. [PMID: 12580629 DOI: 10.1021/ja028458j] [Citation(s) in RCA: 266] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The standard heterogeneous electron-transfer rate constants between substrate gold electrodes and either ferrocene or pentaaminepyridine ruthenium redox couples attached to the electrode surface by various lengths of an alkanethiol bridge as a constituent of a mixed self-assembled monolayer were measured as a function of temperature. The ferrocene was either directly attached to the alkanethiol bridge or attached through an ester (CO(2)) linkage. For long bridge lengths (containing more than 11 methylene groups) the rate constants were measured using either chronoamperometry or cyclic voltammetry; for the shorter bridges, the indirect laser induced temperature jump technique was employed to measure the rate constants. Analysis of the distance (bridge length) dependence of the preexponential factors obtained from an Arrhenius analysis of the rate constant versus temperature data demonstrates a clear limiting behavior at a surprisingly small value of this preexponential factor (much lower than would be expected on the basis of aqueous solvent dynamics). This limit is independent of both the identity of the redox couple and the nature of the linkage of the couple to the bridge, and it is definitely different (smaller) from the limit derived from an equivalent analysis of the rate constant (versus temperature) data for the interfacial electron-transfer reaction through oligophenylenevinylene bridges between gold electrodes and ferrocene. There are a number of possible explanations for this behavior including, for example, the possible effects of bridge conformational flexibility upon the electron-transfer kinetics. Nevertheless, conventional ideas regarding electronic coupling through alkane bridges and solvent dynamics are insufficient to explain the results reported here.
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Affiliation(s)
- John F Smalley
- Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973-5000, USA.
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600
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Lehmann J, Kohler S, Hänggi P, Nitzan A. Rectification of laser-induced electronic transport through molecules. J Chem Phys 2003. [DOI: 10.1063/1.1536639] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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