1
|
Heidari M, Loague Q, Bangle RE, Galoppini E, Meyer GJ. Reorganization Energies for Interfacial Electron Transfer across Phenylene Ethynylene Rigid-Rod Bridges. ACS APPLIED MATERIALS & INTERFACES 2022; 14:35205-35214. [PMID: 35862637 DOI: 10.1021/acsami.2c07151] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
A family of three ruthenium bipyridyl rigid-rod compounds of the general form [Ru(bpy)2(LL)](PF6)2 were anchored to mesoporous thin films of tin-doped indium oxide (ITO) nanocrystals. Here, LL is a 4-substituted 2,2-bipyridine (bpy) ligand with varying numbers of conjugated phenylenethynylene bridge units between the bipyridine ring and anchoring group consisting of a bis-carboxylated isophthalic group. The visible absorption spectra and the formal potentials, Eo(RuIII/II), of the surface anchored rigid-rods were insensitive to the presence of the phenylene ethynylene bridge units in 0.1 M tetrabutyl ammonium perchlorate acetonitrile solutions (TBAClO4/CH3CN). The conductive nature of the ITO enabled potentiostatic control of the Fermi level and hence a means to tune the Gibbs free energy change, -ΔG°, for electron transfer from the ITO to the rigid-rods. Pseudo-rate constants for this electron transfer reaction increased as the number of bridge units decreased at a fixed -ΔG°. With the assumption that the reorganization energy, λ, and the electronic coupling matrix element, Hab, were independent of the applied potential, rate constants measured as a function of -ΔG° and analyzed through Marcus-Gerischer theory provided estimates of Hab and λ. In rough accordance with the dielectric continuum theory, λ was found to increase from 0.61 to 0.80 eV as the number of bridge units was increased. In contrast, Hab decreased markedly with distance from 0.54 to 0.11 cm-1, consistent with non-adiabatic electron transfer. Comparative analysis with previously published studies of bridges with an sp3-hybridized carbon indicated that the phenylene ethynylene bridge does not enhance electronic coupling between the oxide and the rigid-rod acceptor. The implications of these findings for practical applications in solar energy conversion are specifically discussed.
Collapse
Affiliation(s)
- Marzieh Heidari
- Department of Chemistry, Rutgers University, 73 Warren Street, Newark, New Jersey 07102, United States
| | - Quentin Loague
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Rachel E Bangle
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Elena Galoppini
- Department of Chemistry, Rutgers University, 73 Warren Street, Newark, New Jersey 07102, United States
| | - Gerald J Meyer
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| |
Collapse
|
2
|
Fies WA, Dugger JW, Dick JE, Wilder LM, Browning KL, Doucet M, Browning JF, Webb LJ. Direct Measurement of Water Permeation in Submerged Alkyl Thiol Self-Assembled Monolayers on Gold Surfaces Revealed by Neutron Reflectometry. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:5647-5662. [PMID: 30919634 DOI: 10.1021/acs.langmuir.9b00541] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Self-assembled monolayers (SAMs) of alkyl thiols are frequently used to chemically functionalize gold surfaces for applications throughout materials chemistry, electrochemistry, and biotechnology. Despite this, a detailed understanding of the structure of the SAM-water interface generated from both formation and use of the SAM in an aqueous environment is elusive, and analytical measurements of the structure and chemistry of the SAM-water interface are an ongoing experimental challenge. To address this, we used neutron reflectometry (NR) to measure water association with both hydrophobic and hydrophilic SAMs under both wet and dry conditions. SAMs used for this study were made from hydrophobic decanethiol mixed with hydrophilic 11-azido-1-undecanethiol with compositions of 0-100% of the azide-terminated thiol. All SAMs were formed by conventional solution incubation of a Au substrate immersed in ethanol. Each SAM was characterized by grazing incidence angle reflection-absorption Fourier transfer infrared spectroscopy, contact angle goniometry, and electrochemical methods to confirm it was a completely formed monolayer with evidence of extensive crystalline-like domains. NR measured significant absorption of water into each SAM, ranging from 1.6 to 5.7 water molecules per alkyl thiol, when SAMs were immersed in water. Water infiltration was independent of SAM composition and terminal group hydrophilicity. These results demonstrate that water accesses defects, fluid regions, and heterogeneous domains inherent to even well-formed SAMs.
Collapse
Affiliation(s)
- Whitney A Fies
- Department of Chemistry and Texas Materials Institute , The University of Texas at Austin , 2506 Speedway STOP A5300 , Austin , Texas 78712 , United States
| | | | - Jeffrey E Dick
- Department of Chemistry , The University of North Carolina at Chapel Hill , Chapel Hill , North Carolina 27599 , United States
| | - Logan M Wilder
- Department of Chemistry and Texas Materials Institute , The University of Texas at Austin , 2506 Speedway STOP A5300 , Austin , Texas 78712 , United States
| | | | | | | | - Lauren J Webb
- Department of Chemistry and Texas Materials Institute , The University of Texas at Austin , 2506 Speedway STOP A5300 , Austin , Texas 78712 , United States
| |
Collapse
|
3
|
Nikitina VA, Rudnev AV, Nazmutdinov RR, Tsirlina GA, Wandlowski T. Solvent effect on electron transfer through alkanethiols. J Electroanal Chem (Lausanne) 2018. [DOI: 10.1016/j.jelechem.2017.08.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
|
4
|
You T, Lang X, Huang A, Yin P. A DFT study on surface-enhanced Raman spectroscopy of aromatic dithiol derivatives adsorbed on gold nanojunctions. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2018; 188:222-229. [PMID: 28715690 DOI: 10.1016/j.saa.2017.07.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Revised: 07/11/2017] [Accepted: 07/11/2017] [Indexed: 06/07/2023]
Abstract
A computational study on aromatic dithiol derivatives (HS-Ar-X-Ar-SH, X=O, S, Se, NH, CH2, NN, CHCH, CC) interacting with gold cluster(s) was presented to investigate the chemical enhancement mechanism related to surface-enhanced Raman spectroscopy (SERS) for molecular junctions. Density functional theory (DFT) were performed on derivatives molecules as well as their single-end-linked (SEL) or double-end-linked (DEL) complexes for geometric, spectra, electronic and excitation properties, leading to discussions on dominant factor during SERS process. The resulted enhancement factors of SEL and DEL complexes exhibited specific dependency on linking atom or functional group between two phenyls, which was in accordance with the variation of polarizabilities and molecule-cluster transition energy.
Collapse
Affiliation(s)
- Tingting You
- School of Physics and Nuclear Energy Engineering, Beihang University, Beijing 100191, China
| | - Xiufeng Lang
- Material Simulation and Computing Laboratory, Department of Physics, Hebei Normal University of Science & Technology, Qinghuangdao 066004, China
| | - Anping Huang
- School of Physics and Nuclear Energy Engineering, Beihang University, Beijing 100191, China
| | - Penggang Yin
- Key Laboratory of Bio-Inspired Smart Interfacial Science and Technology of Ministry of Education, School of Chemistry, Beihang University, Beijing 100191, China.
| |
Collapse
|
5
|
|
6
|
Wang Y, Wang H, Chen Y, Wang Y, Chen HY, Shan X, Tao N. Fast Electrochemical and Plasmonic Detection Reveals Multitime Scale Conformational Gating of Electron Transfer in Cytochrome c. J Am Chem Soc 2017; 139:7244-7249. [PMID: 28478669 DOI: 10.1021/jacs.7b00839] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Conformational fluctuations play a central role in the electron transfer reactions of molecules. Because the fluctuations can be extremely fast in kinetics and small in amplitude, a technique with fast temporal resolution and high conformational sensitivity is needed to follow the transient electron transfer processes. Here we report on an electrochemically controlled plasmonic detection technique capable of monitoring conformational changes in redox molecules with ns response time. Using the technique, we study the electron transfer reaction and the associated conformational gating of a redox protein (cytochrome c). The study reveals that the conformational gating takes place over a broad range of time scales, from microsecond to millisecond.
Collapse
Affiliation(s)
- Yan Wang
- Biodesign Center for Bioelectronics and Biosensors, Biodesign Institute, Arizona State University , Tempe, Arizona 85287, United States
| | - Hui Wang
- State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University , Nanjing 210093, China
| | - Yuheng Chen
- Biodesign Center for Bioelectronics and Biosensors, Biodesign Institute, Arizona State University , Tempe, Arizona 85287, United States
| | - Yixian Wang
- Department of Chemistry and Biochemistry, California State University, Los Angeles , Los Angeles, California 90032, United States
| | - Hong-Yuan Chen
- State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University , Nanjing 210093, China
| | - Xiaonan Shan
- Department of Electrical & Computer Engineering, University of Houston , Houston, Texas 77024, United States
| | - Nongjian Tao
- Biodesign Center for Bioelectronics and Biosensors, Biodesign Institute, Arizona State University , Tempe, Arizona 85287, United States.,State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University , Nanjing 210093, China
| |
Collapse
|
7
|
Abstract
Extensive simulations of cytochrome c in solution are performed to address the apparent contradiction between large reorganization energies of protein electron transfer typically reported by atomistic simulations and much smaller values produced by protein electrochemistry. The two sets of data are reconciled by deriving the activation barrier for electrochemical reaction in terms of an effective reorganization energy composed of half the Stokes shift (characterizing the medium polarization in response to electron transfer) and the variance reorganization energy (characterizing the breadth of electrostatic fluctuations). This effective reorganization energy is much smaller than each of the two components contributing to it and is fully consistent with electrochemical measurements. Calculations in the range of temperatures between 280 and 360 K combine long, classical molecular dynamics simulations with quantum calculations of the protein active site. The results agree with the Arrhenius plots for the reaction rates and with cyclic voltammetry of cytochrome c immobilized on self-assembled monolayers. Small effective reorganization energy, and the resulting small activation barrier, is a general phenomenology of protein electron transfer allowing fast electron transport within biological energy chains.
Collapse
Affiliation(s)
- Salman S Seyedi
- Department of Physics, Arizona State University , P.O. Box 871504, Tempe, Arizona 85287-1504, United States
| | - Morteza M Waskasi
- School of Molecular Sciences, Arizona State University , P.O. Box 871604, Tempe, Arizona 85287-1604, United States
| | - Dmitry V Matyushov
- Department of Physics, Arizona State University , P.O. Box 871504, Tempe, Arizona 85287-1504, United States.,School of Molecular Sciences, Arizona State University , P.O. Box 871604, Tempe, Arizona 85287-1604, United States
| |
Collapse
|
8
|
Affiliation(s)
- Didier Astruc
- ISM, UMR CNRS 5255; Univ. Bordeaux; 33405 Talence Cedex France
| |
Collapse
|
9
|
Maeda H, Sakamoto R, Nishihara H. Electron transport of bis(terpyridine)iron(II) complex wires on a semiconducting electrode. J Electroanal Chem (Lausanne) 2016. [DOI: 10.1016/j.jelechem.2016.04.027] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
10
|
Demissie AT, Haugstad G, Frisbie CD. Quantitative Surface Coverage Measurements of Self-Assembled Monolayers by Nuclear Reaction Analysis of Carbon-12. J Phys Chem Lett 2016; 7:3477-3481. [PMID: 27537072 DOI: 10.1021/acs.jpclett.6b01363] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Affiliation(s)
- Abel T Demissie
- Department of Chemical Engineering and Materials Science, University of Minnesota , 421 Washington Avenue SE, Minneapolis, Minnesota 55455, United States
| | - Greg Haugstad
- Characterization Facility, University of Minnesota , 100 Union Street SE, Minneapolis, Minnesota 55455, United States
| | - C Daniel Frisbie
- Department of Chemical Engineering and Materials Science, University of Minnesota , 421 Washington Avenue SE, Minneapolis, Minnesota 55455, United States
| |
Collapse
|
11
|
Smith JG, Jain PK. The Ligand Shell as an Energy Barrier in Surface Reactions on Transition Metal Nanoparticles. J Am Chem Soc 2016; 138:6765-73. [DOI: 10.1021/jacs.6b00179] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- Jeremy G. Smith
- Department
of Chemistry, University of Illinois, Urbana−Champaign, Illinois 61801 United States
| | - Prashant K. Jain
- Department
of Chemistry, University of Illinois, Urbana−Champaign, Illinois 61801 United States
- Department
of Physics, University of Illinois, Urbana−Champaign, Illinois 61801 United States
- Materials
Research Lab, University of Illinois, Urbana−Champaign, Illinois 61801 United States
| |
Collapse
|
12
|
Fletcher MC, Alexson DM, Moore MM, Prokes S, Glembocki O, Vivoni A, McCoy R, Mishra S, Tandon P, Hosten CM. Tip enhanced Raman spectroscopy, DFT and PED calculations of 4″-trimethylsilylethylsulfanyl-4,4′-di(phenyleneethynylene)benzene thiol adsorbed on silver. J Mol Struct 2015. [DOI: 10.1016/j.molstruc.2015.07.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
13
|
Mulas A, Hervault YM, Norel L, Rigaut S, Lagrost C. Electron-Transfer Kinetics in Polymetallic Carbon-Rich Ruthenium(II) Bis(σ-arylacetylides) Wires Connected to Gold. ChemElectroChem 2015. [DOI: 10.1002/celc.201500206] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Andrea Mulas
- Institut des Sciences Chimiques de Rennes; UMR 6226; CNRS and Université de Rennes 1; Campus de Beaulieu 35042 Rennes cedex France
| | - Yves-Marie Hervault
- Institut des Sciences Chimiques de Rennes; UMR 6226; CNRS and Université de Rennes 1; Campus de Beaulieu 35042 Rennes cedex France
| | - Lucie Norel
- Institut des Sciences Chimiques de Rennes; UMR 6226; CNRS and Université de Rennes 1; Campus de Beaulieu 35042 Rennes cedex France
| | - Stéphane Rigaut
- Institut des Sciences Chimiques de Rennes; UMR 6226; CNRS and Université de Rennes 1; Campus de Beaulieu 35042 Rennes cedex France
| | - Corinne Lagrost
- Institut des Sciences Chimiques de Rennes; UMR 6226; CNRS and Université de Rennes 1; Campus de Beaulieu 35042 Rennes cedex France
| |
Collapse
|
14
|
Demissie AT, Haugstad G, Frisbie CD. Growth of Thin, Anisotropic, π-Conjugated Molecular Films by Stepwise “Click” Assembly of Molecular Building Blocks: Characterizing Reaction Yield, Surface Coverage, and Film Thickness versus Addition Step Number. J Am Chem Soc 2015; 137:8819-28. [DOI: 10.1021/jacs.5b04512] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Abel T. Demissie
- Department of Chemical Engineering and Materials Science, University of Minnesota, 421 Washington Avenue SE, Minneapolis, Minnesota 55455, United States
| | - Greg Haugstad
- Characterization Facility, University of Minnesota,100 Union
Street SE, Minneapolis, Minnesota 55455, United States
| | - C. Daniel Frisbie
- Department of Chemical Engineering and Materials Science, University of Minnesota, 421 Washington Avenue SE, Minneapolis, Minnesota 55455, United States
| |
Collapse
|
15
|
Heinz LG, Yushchenko O, Neuburger M, Vauthey E, Wenger OS. Tetramethoxybenzene is a Good Building Block for Molecular Wires: Insights from Photoinduced Electron Transfer. J Phys Chem A 2015; 119:5676-84. [DOI: 10.1021/acs.jpca.5b03649] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Luisa G. Heinz
- Department
of Chemistry, University of Basel, St. Johanns-Ring 19, CH-4056 Basel, Switzerland
| | - Oleksandr Yushchenko
- Department
of Physical Chemistry, University of Geneva, 30 quai Ernest Ansermet, CH-1211 Geneva 4, Switzerland
| | - Markus Neuburger
- Department
of Chemistry, University of Basel, St. Johanns-Ring 19, CH-4056 Basel, Switzerland
| | - Eric Vauthey
- Department
of Physical Chemistry, University of Geneva, 30 quai Ernest Ansermet, CH-1211 Geneva 4, Switzerland
| | - Oliver S. Wenger
- Department
of Chemistry, University of Basel, St. Johanns-Ring 19, CH-4056 Basel, Switzerland
| |
Collapse
|
16
|
Liang Y, Thorne JE, Kern ME, Parkinson BA. Sensitization of ZnO single crystal electrodes with CdSe quantum dots. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:12551-12558. [PMID: 25274289 DOI: 10.1021/la5023888] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
CdSe quantum dots (QDs) were attached to single crystal ZnO(0001) and ZnO(1100) substrates using capping groups, 4-mercaptobenzoic acid, 2-mercaptoacetic acid, 3-mercaptopropionic acid, 8-mercaptooctanoic acid, and 11-mercaptoundecanoic acid, as bifunctional linker molecules. The spectral response and photosensitization yields of the adsorbed QDs were studied with photocurrent spectroscopy. Atomic force microscopy (AFM) was used to verify the surface structure of the ZnO crystals and to examine the coverage and arrangement of the QDs on the single crystal surface. The inner-sphere aqueous redox couple Sx(2-)/S(2-), often used as a regenerator for chalcogenide-based QDs, as well as outer-sphere redox couples such as ferrocene, were able to regenerate the photoexcited CdSe QDs and suppress their photocorrosion. Differences in the binding of the QDs to different ZnO crystal faces are also reported.
Collapse
Affiliation(s)
- Yongqi Liang
- Department of Chemistry and School of Energy Resources, University of Wyoming , Laramie, Wyoming 82071, United States
| | | | | | | |
Collapse
|
17
|
|
18
|
Dickson-Karn NM, Olson CM, Leu WCW, Hartley CS. Intramolecularcharge transfer in donor-bridge-acceptor compounds with paired linearly conjugated or cross-conjugated pathways. J PHYS ORG CHEM 2014. [DOI: 10.1002/poc.3314] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
| | - Courtney M. Olson
- Department of Chemistry and Biochemistry; Ohio Northern University; Ada OH 45810 USA
| | - Wade C. W. Leu
- Department of Chemistry and Biochemistry; Miami University; Oxford OH 45056 USA
| | - C. Scott Hartley
- Department of Chemistry and Biochemistry; Miami University; Oxford OH 45056 USA
| |
Collapse
|
19
|
Ding L, Bond AM, Zhai J, Zhang J. Utilization of nanoparticle labels for signal amplification in ultrasensitive electrochemical affinity biosensors: A review. Anal Chim Acta 2013; 797:1-12. [DOI: 10.1016/j.aca.2013.07.035] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2013] [Revised: 07/08/2013] [Accepted: 07/14/2013] [Indexed: 12/11/2022]
|
20
|
Song CK, White AC, Zeng L, Leever BJ, Clark MD, Emery JD, Lou SJ, Timalsina A, Chen LX, Bedzyk MJ, Marks TJ. Systematic investigation of organic photovoltaic cell charge injection/performance modulation by dipolar organosilane interfacial layers. ACS APPLIED MATERIALS & INTERFACES 2013; 5:9224-9240. [PMID: 23942417 DOI: 10.1021/am4030609] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
With the goal of investigating and enhancing anode performance in bulk-heterojunction (BHJ) organic photovoltaic (OPV) cells, the glass/tin-doped indium oxide (ITO) anodes are modified with a series of robust silane-tethered bis(fluoroaryl)amines to form self-assembled interfacial layers (IFLs). The modified ITO anodes are characterized by contact angle measurements, X-ray reflectivity, ultraviolet photoelectron spectroscopy, X-ray photoelectron spectroscopy, grazing incidence X-ray diffraction, atomic force microscopy, and cyclic voltammetry. These techniques reveal the presence of hydrophobic amorphous monolayers of 6.68 to 9.76 Å thickness, and modified anode work functions ranging from 4.66 to 5.27 eV. Two series of glass/ITO/IFL/active layer/LiF/Al BHJ OPVs are fabricated with the active layer = poly(3-hexylthiophene):phenyl-C71-butyric acid methyl ester (P3HT:PC71BM) or poly[[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b']dithiophene-2,6-diyl][3-fluoro-2-[(2-ethylhexyl)-carbonyl]thi-eno[3,4-b]thiophenediyl]]:phenyl-C71-butyric acid methyl ester (PTB7:PC71BM). OPV analysis under AM 1.5G conditions reveals significant performance enhancement versus unmodified glass/ITO anodes. Strong positive correlations between the electrochemically derived heterogeneous electron transport rate constants (ks) and the device open circuit voltage (Voc), short circuit current (Jsc), hence OPV power conversion efficiency (PCE), are observed for these modified anodes. Furthermore, the strong functional dependence of the device response on ks increases as greater densities of charge carriers are generated in the BHJ OPV active layer, and is attributable to enhanced anode carrier extraction in the case of high-ks IFLs.
Collapse
Affiliation(s)
- Charles Kiseok Song
- Department of Chemistry and the Argonne-Northwestern Solar Energy Research Center, Northwestern University , 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
21
|
Green K, Gauthier N, Sahnoune H, Halet JF, Paul F, Fabre B. Covalent Immobilization of Redox-Active Fe(κ2-dppe)(η5-C5Me5)-Based π-Conjugated Wires on Oxide-Free Hydrogen-Terminated Silicon Surfaces. Organometallics 2013. [DOI: 10.1021/om4006017] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Affiliation(s)
- Katy Green
- Institut
des Sciences Chimiques de Rennes, UMR 6226 CNRS, Université de Rennes 1, Campus
de Beaulieu, 35042 Rennes Cedex, France
| | - Nicolas Gauthier
- Institut
des Sciences Chimiques de Rennes, UMR 6226 CNRS, Université de Rennes 1, Campus
de Beaulieu, 35042 Rennes Cedex, France
| | - Hiba Sahnoune
- Institut
des Sciences Chimiques de Rennes, UMR 6226 CNRS, Université de Rennes 1, Campus
de Beaulieu, 35042 Rennes Cedex, France
| | - Jean-François Halet
- Institut
des Sciences Chimiques de Rennes, UMR 6226 CNRS, Université de Rennes 1, Campus
de Beaulieu, 35042 Rennes Cedex, France
| | - Frédéric Paul
- Institut
des Sciences Chimiques de Rennes, UMR 6226 CNRS, Université de Rennes 1, Campus
de Beaulieu, 35042 Rennes Cedex, France
| | - Bruno Fabre
- Institut
des Sciences Chimiques de Rennes, UMR 6226 CNRS, Université de Rennes 1, Campus
de Beaulieu, 35042 Rennes Cedex, France
| |
Collapse
|
22
|
Johansson PG, Kopecky A, Galoppini E, Meyer GJ. Distance Dependent Electron Transfer at TiO2 Interfaces Sensitized with Phenylene Ethynylene Bridged RuII–Isothiocyanate Compounds. J Am Chem Soc 2013; 135:8331-41. [DOI: 10.1021/ja402193f] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Patrik G. Johansson
- Departments of Chemistry and Materials Science & Engineering, Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, United States
| | - Andrew Kopecky
- Department of Chemistry, Rutgers University, 73 Warren St, Newark, New Jersey
07102, United States
| | - Elena Galoppini
- Department of Chemistry, Rutgers University, 73 Warren St, Newark, New Jersey
07102, United States
| | - Gerald J. Meyer
- Departments of Chemistry and Materials Science & Engineering, Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, United States
| |
Collapse
|
23
|
Reiner JE, Robertson JWF, Burden DL, Burden LK, Balijepalli A, Kasianowicz JJ. Temperature sculpting in yoctoliter volumes. J Am Chem Soc 2013; 135:3087-94. [PMID: 23347384 DOI: 10.1021/ja309892e] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The ability to perturb large ensembles of molecules from equilibrium led to major advances in understanding reaction mechanisms in chemistry and biology. Here, we demonstrate the ability to control, measure, and make use of rapid temperature changes in fluid volumes that are commensurate with the size of single molecules. The method is based on attaching gold nanoparticles to a single nanometer-scale pore formed by a protein ion channel. Visible laser light incident on the nanoparticles causes a rapid and large increase of the adjacent solution temperature, which is estimated from the change in the nanopore ionic conductance. The temperature shift also affects the ability of individual molecules to enter into and interact with the nanopore. This technique could significantly improve sensor systems and force measurements based on single nanopores, thereby enabling a method for single molecule thermodynamics and kinetics.
Collapse
Affiliation(s)
- Joseph E Reiner
- Department of Physics, Virginia Commonwealth University, Richmond, Virginia 23284, USA.
| | | | | | | | | | | |
Collapse
|
24
|
Muhammad H, Koczkur KM, Kycia AH, Houmam A. Nitro-substituted arene sulfenyl chlorides as precursors to the formation of aromatic SAMs. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:15853-15863. [PMID: 23078107 DOI: 10.1021/la303395e] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The formation of aromatic SAMs on Au(111) using three nitro-substituted arene sulfenyl chlorides (4-nitrophenyl sulfenyl chloride (1), 2-nitrophenyl sulfenyl chloride (2), and 2,4-dinitrophenyl sulfenyl chloride (3)) is studied. The formation of SAMs and their quality are investigated as a function of the position of the nitro substituent(s) on the aromatic ring. The modified surfaces are characterized by X-ray photoelectron spectroscopy (XPS), scanning tunneling microscopy (STM), polarization modulation infrared reflection absorption spectroscopy (PMIRRAS), and cyclic voltammetry (CV). The results show that all three compounds are deposited on Au within very short times. The corresponding coverages are determined using CV. However, only compound 1 forms stable, long-range, well-ordered SAMs. The 4-nitrophenyl thiolate is adsorbed nearly vertically on the Au surface. Compounds 2 and 3 both form lower-quality SAMs where the adsorbed nitro-phenyl thiolates are more tilted. These SAMs are less stable than the ones obtained with the 4-nitrosubsituted precursor and decompose with time, leaving only sulfur on the gold surface.
Collapse
Affiliation(s)
- Hamida Muhammad
- Electrochemical Technology Centre, Department of Chemistry, University of Guelph, Guelph, Ontario, Canada
| | | | | | | |
Collapse
|
25
|
Synthesis of a series of 1,n′-disubstituted ferrocene derivatives containing disulfides. Inorganica Chim Acta 2012. [DOI: 10.1016/j.ica.2012.05.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
26
|
Gambardella AA, Feldberg SW, Murray RW. Electron Transfer Dynamics of Iridium Oxide Nanoparticles Attached to Electrodes by Self-Assembled Monolayers. J Am Chem Soc 2012; 134:5774-7. [DOI: 10.1021/ja301212r] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Alessa A. Gambardella
- Kenan Laboratories of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599, United
States
| | - Stephen W. Feldberg
- Chemistry Department, Brookhaven National Laboratory, Upton, New York 11973,
United States
| | - Royce W. Murray
- Kenan Laboratories of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599, United
States
| |
Collapse
|
27
|
Houmam A, Muhammad H, Koczkur KM. Physical structure of standing-up aromatic SAMs revealed by scanning tunneling microscopy. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:13544-13553. [PMID: 21970561 DOI: 10.1021/la202928z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Long-range-ordered aromatic SAMs are formed on Au(111) using 4-nitrophenyl sulfenyl chloride as a precursor. Although the main structure is a √3 × √3 with a molecular density similar to that usually found for aliphatic SAMs, particular spots presenting specific shapes are also observed by STM. These include hexagons, partial hexagons, parallelograms, and zigzags resulting from specific arrangements of adsorbed molecules. These molecular arrangements are reversible as they form and dissociate or "vanish" in various areas on the surface. STM shows that these particular structures provide some order to their surrounding because areas void of these structures look less ordered. More interestingly, STM shows submolecular details of the molecules involved in forming these structures, hence providing direct experimental evidence for the ability of the STM to provide physical structure information of standing up SAMs. This is indeed a heavily debated question, and this work reports the first experimental example where submolecular physical structure is revealed by STM for standing-up SAMs.
Collapse
Affiliation(s)
- Abdelaziz Houmam
- Electrochemical Technology Centre, Department of Chemistry, University of Guelph, Guelph, Ontario, Canada N1G 2W1.
| | | | | |
Collapse
|
28
|
Ultrasensitive electrochemical immunosensor employing glucose oxidase catalyzed deposition of gold nanoparticles for signal amplification. Biosens Bioelectron 2011; 27:53-7. [DOI: 10.1016/j.bios.2011.06.007] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2011] [Revised: 06/09/2011] [Accepted: 06/10/2011] [Indexed: 11/19/2022]
|
29
|
Nakayama H, Kimura S. Suppression of HOMO–LUMO Transition in a Twist Form of Oligo(phenyleneethynylene) Clamped by a Right-Handed Helical Peptide. J Phys Chem A 2011; 115:8960-8. [DOI: 10.1021/jp200997c] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Hidenori Nakayama
- Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Kyoto-Daigaku-Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
| | - Shunsaku Kimura
- Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Kyoto-Daigaku-Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
| |
Collapse
|
30
|
Bullock JP, Mashkina E, Bond AM. Activation Parameters Derived From a Temperature Dependent Large Amplitude ac Voltammetric Study of the Electrode Kinetics of the Cp2M0/+Redox Couples (M = Fe, Co) at a Glassy Carbon Electrode. J Phys Chem A 2011; 115:6493-502. [DOI: 10.1021/jp2021787] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- John P. Bullock
- Division of Natural Sciences & Mathematics, Bennington College, Bennington, Vermont 05201, United States
| | - Elena Mashkina
- School of Chemistry, Monash University, Clayton, Victoria 3800, Australia
| | - Alan M. Bond
- School of Chemistry, Monash University, Clayton, Victoria 3800, Australia
| |
Collapse
|
31
|
Cui L, Liu B, Vonlanthen D, Mayor M, Fu Y, Li JF, Wandlowski T. In Situ Gap-Mode Raman Spectroscopy on Single-Crystal Au(100) Electrodes: Tuning the Torsion Angle of 4,4′-Biphenyldithiols by an Electrochemical Gate Field. J Am Chem Soc 2011; 133:7332-5. [DOI: 10.1021/ja2020185] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Li Cui
- Institute of Urban Environment, Chinese Academy of Sciences, 1799 Jimei Road, Xiamen 361021, P. R. China
| | - Bo Liu
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, Bern CH-3012, Switzerland
| | - David Vonlanthen
- Department of Chemistry, University of Basel, St.-Johanns-Ring 19, 4056 Basel, Switzerland
| | - Marcel Mayor
- Department of Chemistry, University of Basel, St.-Johanns-Ring 19, 4056 Basel, Switzerland
- Institute for Nanotechnology, Karlsuhe Institute of Technlogy (KIT), P.O. Box 3640, 76021 Karlsruhe, Germany
| | - Yongchun Fu
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, Bern CH-3012, Switzerland
| | - Jian-Feng Li
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, Bern CH-3012, Switzerland
| | - Thomas Wandlowski
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, Bern CH-3012, Switzerland
| |
Collapse
|
32
|
Rosendahl SM, Burgess IJ. Charge transfer and SEIRAS studies of 1,4-benzoquinone functionalized mixed monothiol/dithiol self-assembled monolayers. Electrochim Acta 2011. [DOI: 10.1016/j.electacta.2011.01.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
33
|
Silien C, Lahaye D, Caffio M, Schaub R, Champness NR, Buck M. Electrodeposition of palladium onto a pyridine-terminated self-assembled monolayer. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:2567-2574. [PMID: 21338091 DOI: 10.1021/la104561j] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The electrodeposition of Pd onto self-assembled monolayers (SAMs) of 3-(4-pyridine-4-ylphenyl)propane-1-thiol on Au(111) has been investigated by scanning tunneling microscopy. Two schemes are compared: One involves an established two-step procedure where Pd(2+) ions are first coordinated to the pyridine moieties and subsequently reduced in Pd(2+)-free electrolyte. The second deposition routine involves electroreduction in an electrolyte containing low concentration of Pd(2+) which merges both steps and, thus, significantly simplifies metal deposition onto pyridine-terminated SAMs. Both strategies produce identical Pd nanoparticles (NPs) which exhibit a narrow size distribution and an apparent STM height of ∼2.4 nm. The observation of a Coulomb blockade and easy displacement of the nanoparticles in STM experiments evidence deposition on top of the SAM. The NPs are concluded to be essentially spherical. Growth of the NPs is found to be self-limiting since repeating the complexation-deposition cycle increases the density of the nanoparticles rather than their size but only close to full coverage. At high concentration of the Pd(2+) electrolyte, deposition on top of the SAM is impeded by a competitive mushroom-type growth.
Collapse
Affiliation(s)
- Christophe Silien
- EaStCHEM School of Chemistry, University of St. Andrews , Scotland, U.K
| | | | | | | | | | | |
Collapse
|
34
|
Feng S, Huang Y, Wang Q, Qing FL. Nonbiofouling surface based on amphiphilic alkanethiol self-assembled monolayers. SURF INTERFACE ANAL 2011. [DOI: 10.1002/sia.3615] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
35
|
Browne KP, Grzybowski BA. Controlling the properties of self-assembled monolayers by substrate curvature. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:1246-1250. [PMID: 21090598 DOI: 10.1021/la103960q] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Properties of self-assembled monolayers (SAMs) can be tailored by the curvature of the underlying surface. This is so because on a curved support the density of SAM headgroups is always smaller than that of the surface-attachment sites. This density difference increases with increasing curvature and is most pronounced for SAMs formed on nanoscopic particles. This Perspective describes systems in which nanoscale curvature causes pronounced changes in the pK(a) of acid-presenting SAMs or in the electrochemical potential of redox-active molecules (including supramolecular "switches") attached to nanoparticles. It is suggested that in nanoparticles having regions of different curvature these geometrical differences can translate into site-selective charging; such "patchy" particles could be used as building blocks of pH-sensitive assemblies.
Collapse
Affiliation(s)
- Kevin P Browne
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, USA
| | | |
Collapse
|
36
|
Ricci AM, Tognalli N, de la Llave E, Vericat C, Méndez De Leo LP, Williams FJ, Scherlis D, Salvarezza R, Calvo EJ. Electrochemistry of Os(2,2′-bpy)2ClPyCH2NHCOPh tethered to Au electrodes by S–Au and C–Au junctions. Phys Chem Chem Phys 2011; 13:5336-45. [DOI: 10.1039/c0cp02409k] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
37
|
Waldeck DH, Khoshtariya DE. Fundamental Studies of Long- and Short-Range Electron Exchange Mechanisms between Electrodes and Proteins. MODERN ASPECTS OF ELECTROCHEMISTRY 2011. [DOI: 10.1007/978-1-4614-0347-0_2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
|
38
|
Charge Transport in Single Molecular Junctions at the Solid/Liquid Interface. Top Curr Chem (Cham) 2011; 313:121-88. [DOI: 10.1007/128_2011_238] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
|
39
|
Ho MY, Li P, Estrela P, Goodchild S, Migliorato P. Detection of molecular interactions with modified ferrocene self-assembled monolayers. J Phys Chem B 2010; 114:10661-5. [PMID: 20701392 DOI: 10.1021/jp104560e] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Ferrocene-terminated self-assembled monolayers (Fc-SAMs) are one of the most studied molecular aggregates on metal electrodes. They are easy to fabricate and provide a stable and reproducible system to investigate the effect of the microenvironment on the electron transfer parameters. We propose a novel application for Fc-SAMs, the detection of molecular interactions, based on the modification of the SAM with target-specific receptors. Mixed SAMs were fabricated by coimmobilization on Au electrodes of thiolated alkane chains with three different head groups: hydroxy terminating head group, ferrocene head group, and a functional head group such as biotin. Upon binding, the intrinsic electric charge of the target (e.g., streptavidin) modifies the electrostatic potential at the plane of electron transfer, causing a shift in the formal potential E degrees '. The SAMs were characterized by AC voltammetry. The detection mechanism is confirmed by measurements of formal potential as a function of electrolyte pH.
Collapse
Affiliation(s)
- Man Yi Ho
- University of Cambridge, Engineering Department, Electrical Engineering Division, UK
| | | | | | | | | |
Collapse
|
40
|
Walther ME, Grilj J, Hanss D, Vauthey E, Wenger OS. Photoinduced Processes in Fluorene-Bridged Rhenium-Phenothiazine Dyads - Comparison of Electron Transfer Across Fluorene, Phenylene, and Xylene Bridges. Eur J Inorg Chem 2010. [DOI: 10.1002/ejic.201000645] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
41
|
Eckermann AL, Feld DJ, Shaw JA, Meade TJ. Electrochemistry of redox-active self-assembled monolayers. Coord Chem Rev 2010; 254:1769-1802. [PMID: 20563297 PMCID: PMC2885823 DOI: 10.1016/j.ccr.2009.12.023] [Citation(s) in RCA: 357] [Impact Index Per Article: 25.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Redox-active self-assembled monolayers (SAMs) provide an excellent platform for investigating electron transfer kinetics. Using a well-defined bridge, a redox center can be positioned at a fixed distance from the electrode and electron transfer kinetics probed using a variety of electrochemical techniques. Cyclic voltammetry, AC voltammetry, electrochemical impedance spectroscopy, and chronoamperometry are most commonly used to determine the rate of electron transfer of redox-activated SAMs. A variety of redox species have been attached to SAMs, and include transition metal complexes (e.g., ferrocene, ruthenium pentaammine, osmium bisbipyridine, metal clusters) and organic molecules (e.g., galvinol, C(60)). SAMs offer an ideal environment to study the outer-sphere interactions of redox species. The composition and integrity of the monolayer and the electrode material influence the electron transfer kinetics and can be investigated using electrochemical methods. Theoretical models have been developed for investigating SAM structure. This review discusses methods and monolayer compositions for electrochemical measurements of redox-active SAMs.
Collapse
|
42
|
Chemical routes to fine tuning the redox potential of monolayers covalently attached on H–Si(100). Electrochim Acta 2010. [DOI: 10.1016/j.electacta.2010.05.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
43
|
Zhang Y, Galoppini E. Organic polyaromatic hydrocarbons as sensitizing model dyes for semiconductor nanoparticles. CHEMSUSCHEM 2010; 3:410-428. [PMID: 20135672 DOI: 10.1002/cssc.200900233] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The study of interfacial charge-transfer processes (sensitization) of a dye bound to large-bandgap nanostructured metal oxide semiconductors, including TiO(2), ZnO, and SnO(2), is continuing to attract interest in various areas of renewable energy, especially for the development of dye-sensitized solar cells (DSSCs). The scope of this Review is to describe how selected model sensitizers prepared from organic polyaromatic hydrocarbons have been used over the past 15 years to elucidate, through a variety of techniques, fundamental aspects of heterogeneous charge transfer at the surface of a semiconductor. This Review does not focus on the most recent or efficient dyes, but rather on how model dyes prepared from aromatic hydrocarbons have been used, over time, in key fundamental studies of heterogeneous charge transfer. In particular, we describe model chromophores prepared from anthracene, pyrene, perylene, and azulene. As the level of complexity of the model dye-bridge-anchor group compounds has increased, the understanding of some aspects of very complex charge transfer events has improved. The knowledge acquired from the study of the described model dyes is of importance not only for DSSC development but also to other fields of science for which electronic processes at the molecule/semiconductor interface are relevant.
Collapse
Affiliation(s)
- Yongyi Zhang
- Department of Chemistry, Rutgers, the State University of New Jersey, Newark, NJ 07102,USA
| | | |
Collapse
|
44
|
Affiliation(s)
- Joseph C. Genereux
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125
| | - Jacqueline K. Barton
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125
| |
Collapse
|
45
|
Eckermann AL, Shaw JA, Meade TJ. Kinetic dispersion in redox-active dithiocarbamate monolayers. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:2904-13. [PMID: 19877702 PMCID: PMC4477844 DOI: 10.1021/la902839r] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Dithiocarbamates (dtcs) have been implicated as important gold-binding groups in molecular electronics. Dtcs have two alkane branches connected at a single anchoring point that has a bidentate resonance structure. Forming readily in situ by the combination of secondary amines and CS(2), dtcs adsorb quickly onto gold surfaces. Electroactive self-assembled monolayers (eSAMs) were prepared by the coadsorption of ferrocene dialkyldithiocarbamates (Fc dtcs) with diluent dtcs on gold electrodes. Short and long alkane chains were used (11 and 16 methylene groups, respectively), and a polar ester group was incorporated. Cyclic voltammetry (CV) shows that the electrochemistry is quasi-reversible. At high surface coverage, the peak separations and full widths at half-maximum for Fc dtcs deviate from theoretical values and are analogous to that of ferrocene alkane thiols on gold at high surface coverage. Importantly, these features do not change at low Fc dtc surface coverage as observed for ferrocene alkane thiols. Ferrocene dtcs were used to label monolayer defect sites and to demonstrate the exchange of surface-bound dtcs with solution dtcs. Finally, the rate of electron transfer was analyzed using Tafel plots and ac voltammetric methods. The results for both techniques are consistent with a kinetically disperse population of redox sites. The length of the diluent alkane chain appears to have an effect on the distribution of electron-transfer rates, likely because of the eSAM structure. This work indicates that structurally, Fc dtc eSAMs are fundamentally different from alkane thiol SAMs on gold.
Collapse
Affiliation(s)
- Amanda L. Eckermann
- Departments of Chemistry, Biochemistry and Molecular and Cell Biology, Neurobiology and Physiology, and Radiology, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208
| | - Justine A. Shaw
- Departments of Chemistry, Biochemistry and Molecular and Cell Biology, Neurobiology and Physiology, and Radiology, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208
| | - Thomas J. Meade
- Departments of Chemistry, Biochemistry and Molecular and Cell Biology, Neurobiology and Physiology, and Radiology, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208
| |
Collapse
|
46
|
Mishchenko A, Vonlanthen D, Meded V, Bürkle M, Li C, Pobelov IV, Bagrets A, Viljas JK, Pauly F, Evers F, Mayor M, Wandlowski T. Influence of conformation on conductance of biphenyl-dithiol single-molecule contacts. NANO LETTERS 2010; 10:156-63. [PMID: 20025266 DOI: 10.1021/nl903084b] [Citation(s) in RCA: 185] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
The conductance of a family of biphenyl-dithiol derivatives with conformationally fixed torsion angle was measured using the scanning tunneling microscopy (STM)-break-junction method. We found that it depends on the torsion angle phi between two phenyl rings; twisting the biphenyl system from flat (phi = 0 degrees ) to perpendicular (phi = 90 degrees ) decreased the conductance by a factor of 30. Detailed calculations of transport based on density functional theory and a two level model (TLM) support the experimentally obtained cos(2) phi correlation between the junction conductance G and the torsion angle phi. The TLM describes the pair of hybridizing highest occupied molecular orbital (HOMO) states on the phenyl rings and illustrates that the pi-pi coupling dominates the transport under "off-resonance" conditions where the HOMO levels are well separated from the Femi energy.
Collapse
Affiliation(s)
- Artem Mishchenko
- Department of Chemistry and Biochemistry, University of Bern, Bern, Switzerland
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
47
|
Chaudhry BR, Wilton-Ely JDET, Tabor AB, Caruana DJ. Effect of peptide orientation on electron transfer. Phys Chem Chem Phys 2010; 12:9996-8. [DOI: 10.1039/c0cp00226g] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
|
48
|
Khoshtariya DE, Dolidze TD, van Eldik R. Unusual mechanism for the short-range electron transfer within gold-alkanethiol-ionic-liquid films of subnanometer thickness. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2009; 80:065101. [PMID: 20365213 DOI: 10.1103/physreve.80.065101] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2009] [Revised: 11/06/2009] [Indexed: 05/29/2023]
Abstract
Exploiting nanoscopically tunable composite gold-alkanethiol-ionic-liquid/ferrocene self-assembled systems with tunable electron transfer distance, we discovered in the case of thinner alkanethiol films a thermally activated electron transfer pattern totally controlled by the viscosity-related slow relaxation mode(s) of the ionic liquid acting as the reactant's fluctuating environment. This pattern manifested through the activation enthalpy and volume parameters that are identical to those for viscous flow was explained in terms of the extreme adiabatic mechanism with a vanishing Marcus barrier (via the exponential Franck-Condon-like term approaching unity).
Collapse
Affiliation(s)
- Dimitri E Khoshtariya
- Department of Physics and Institute for Biophysics and Bionanosciences, I. Javakhishvili Tbilisi State University, I. Chavchavadze Avenue 3, Tbilisi, Georgia.
| | | | | |
Collapse
|
49
|
Meylemans HA, Damrauer NH. Controlling Electron Transfer through the Manipulation of Structure and Ligand-Based Torsional Motions: A Computational Exploration of Ruthenium Donor−Acceptor Systems using Density Functional Theory. Inorg Chem 2009; 48:11161-75. [DOI: 10.1021/ic901637b] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Heather A. Meylemans
- Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309
| | - Niels H. Damrauer
- Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309
| |
Collapse
|
50
|
Han D, Kim YR, Oh JW, Kim TH, Mahajan RK, Kim JS, Kim H. A regenerative electrochemical sensor based on oligonucleotide for the selective determination of mercury(II). Analyst 2009; 134:1857-62. [PMID: 19684910 DOI: 10.1039/b908457f] [Citation(s) in RCA: 113] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
We have developed a selective, sensitive, and re-usable electrochemical sensor for Hg2+ ion detection. This sensor is based on the Hg2+-induced conformational change of a single-stranded DNA (ssDNA) which involves an electroactive, ferrocene-labeled DNA hairpin structure and provides strategically the selective binding of a thymine-thymine mismatch for the Hg2+ ion. The ferrocene-labeled DNA is self-assembled through S-Au bonding on a polycrystalline gold electrode surface and the surface blocked with 3-mercapto-1-propanol to form a mixed monolayer. The modified electrode showed a voltammetric signal due to a one-step redox reaction of the surface-confined ferrocenyl moiety. The 'signal-on' upon mercury binding could be attributed to a change in the conformation of ferrocene-labeled DNA from an open structure to a restricted hairpin structure. The differential pulse voltammetry (DPV) of the modified electrode showed a linear response of the ferrocene oxidation signal with increase of Hg2+ concentration in the range between 0.1 and 2 microM with a detection limit of 0.1 microM. The molecular beacon mercury(II) ion sensor was amenable to regeneration by simply unfolding the ferrocene-labeled DNA in 10 microM cysteine, and could be regenerated with no loss in signal gain upon subsequent mercury(II) ion binding.
Collapse
Affiliation(s)
- Donghoon Han
- Department of Chemistry, Seoul National University, Seoul 151-747, South Korea
| | | | | | | | | | | | | |
Collapse
|