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Nguyen DT, Freitag M, Gutheil C, Sotthewes K, Tyler BJ, Böckmann M, Das M, Schlüter F, Doltsinis NL, Arlinghaus HF, Ravoo BJ, Glorius F. Ein auf Arylazopyrazol basierendes N‐heterocyclisches Carben als Photoschalter auf Goldoberflächen: Lichtschaltbare Benetzbarkeit, Austrittsarbeit und Leitwert. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202003523] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- D. Thao Nguyen
- Organisch-Chemisches Institut Westfälische Wilhelms-Universität Münster Corrensstraße 40 48149 Münster Deutschland
- Center for Soft Nanoscience (SoN) Westfälische Wilhelms-Universität Münster Busso-Peus-Straße 10 48149 Münster Deutschland
| | - Matthias Freitag
- Organisch-Chemisches Institut Westfälische Wilhelms-Universität Münster Corrensstraße 40 48149 Münster Deutschland
| | - Christian Gutheil
- Organisch-Chemisches Institut Westfälische Wilhelms-Universität Münster Corrensstraße 40 48149 Münster Deutschland
| | - Kai Sotthewes
- Physics of Interfaces and Nanomaterials MESA+ Institute for Nanotechnology University of Twente P.O. Box 217 7500 AE Enschede Niederlande
| | - Bonnie J. Tyler
- Physikalisches Institut Westfälische Wilhelms-Universität Münster Wilhelm-Klemm-Straße 10 48149 Münster Deutschland
| | - Marcus Böckmann
- Institute for Solid State Theory and Center for Multiscale Theory & Computation Westfälische Wilhelms-Universität Münster Wilhelm-Klemm-Straße 10 48149 Münster Deutschland
| | - Mowpriya Das
- Organisch-Chemisches Institut Westfälische Wilhelms-Universität Münster Corrensstraße 40 48149 Münster Deutschland
| | - Friederike Schlüter
- Organisch-Chemisches Institut Westfälische Wilhelms-Universität Münster Corrensstraße 40 48149 Münster Deutschland
- Center for Soft Nanoscience (SoN) Westfälische Wilhelms-Universität Münster Busso-Peus-Straße 10 48149 Münster Deutschland
| | - Nikos L. Doltsinis
- Institute for Solid State Theory and Center for Multiscale Theory & Computation Westfälische Wilhelms-Universität Münster Wilhelm-Klemm-Straße 10 48149 Münster Deutschland
| | - Heinrich F. Arlinghaus
- Physikalisches Institut Westfälische Wilhelms-Universität Münster Wilhelm-Klemm-Straße 10 48149 Münster Deutschland
| | - Bart Jan Ravoo
- Organisch-Chemisches Institut Westfälische Wilhelms-Universität Münster Corrensstraße 40 48149 Münster Deutschland
- Center for Soft Nanoscience (SoN) Westfälische Wilhelms-Universität Münster Busso-Peus-Straße 10 48149 Münster Deutschland
| | - Frank Glorius
- Organisch-Chemisches Institut Westfälische Wilhelms-Universität Münster Corrensstraße 40 48149 Münster Deutschland
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Nguyen DT, Freitag M, Gutheil C, Sotthewes K, Tyler BJ, Böckmann M, Das M, Schlüter F, Doltsinis NL, Arlinghaus HF, Ravoo BJ, Glorius F. An Arylazopyrazole-Based N-Heterocyclic Carbene as a Photoswitch on Gold Surfaces: Light-Switchable Wettability, Work Function, and Conductance. Angew Chem Int Ed Engl 2020; 59:13651-13656. [PMID: 32271973 DOI: 10.1002/anie.202003523] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2020] [Revised: 04/08/2020] [Indexed: 12/13/2022]
Abstract
A novel photoresponsive and fully conjugated N-heterocyclic carbene (NHC) has been synthesized that combines the excellent photophysical properties of arylazopyrazoles (AAPs) with an NHC that acts as a robust surface anchor (AAP-BIMe). The formation of self-assembled monolayers (SAMs) on gold was proven by ToF-SIMS and XPS, and the organic film displayed a very high stability at elevated temperatures. This stability was also reflected in a high desorption energy, which was determined by temperature-programmed SIMS measurements. E-/Z-AAP-BIMe@Au photoisomerization resulted in reversible alterations of the surface energy (i.e. wettability), the surface potential (i.e. work function), and the conductance (i.e. resistance). The effects could be explained by the difference in the dipole moment of the isomers. Furthermore, sequential application of a dummy ligand by microcontact printing and subsequent backfilling with AAP-BIMe allowed its patterning on gold. To the best of our knowledge, this is the first example of a photoswitchable NHC on a gold surface. These properties of AAP-BIMe@Au illustrate its suitability as a molecular switch for electronic devices.
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Affiliation(s)
- D Thao Nguyen
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstrasse 40, 48149, Münster, Germany.,Center for Soft Nanoscience (SoN), Westfälische Wilhelms-Universität Münster, Busso-Peus-Strasse 10, 48149, Münster, Germany
| | - Matthias Freitag
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstrasse 40, 48149, Münster, Germany
| | - Christian Gutheil
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstrasse 40, 48149, Münster, Germany
| | - Kai Sotthewes
- Physics of Interfaces and Nanomaterials, MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500, AE, Enschede, The Netherlands
| | - Bonnie J Tyler
- Physikalisches Institut, Westfälische Wilhelms-Universität Münster, Wilhelm-Klemm-Strasse 10, 48149, Münster, Germany
| | - Marcus Böckmann
- Institute for Solid State Theory and Center for Multiscale Theory & Computation, Westfälische Wilhelms-Universität Münster, Wilhelm-Klemm-Strasse 10, 48149, Münster, Germany
| | - Mowpriya Das
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstrasse 40, 48149, Münster, Germany
| | - Friederike Schlüter
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstrasse 40, 48149, Münster, Germany.,Center for Soft Nanoscience (SoN), Westfälische Wilhelms-Universität Münster, Busso-Peus-Strasse 10, 48149, Münster, Germany
| | - Nikos L Doltsinis
- Institute for Solid State Theory and Center for Multiscale Theory & Computation, Westfälische Wilhelms-Universität Münster, Wilhelm-Klemm-Strasse 10, 48149, Münster, Germany
| | - Heinrich F Arlinghaus
- Physikalisches Institut, Westfälische Wilhelms-Universität Münster, Wilhelm-Klemm-Strasse 10, 48149, Münster, Germany
| | - Bart Jan Ravoo
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstrasse 40, 48149, Münster, Germany.,Center for Soft Nanoscience (SoN), Westfälische Wilhelms-Universität Münster, Busso-Peus-Strasse 10, 48149, Münster, Germany
| | - Frank Glorius
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstrasse 40, 48149, Münster, Germany
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Cocchi C, Draxl C. Understanding the effects of packing and chemical terminations on the optical excitations of azobenzene-functionalized self-assembled monolayers. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2017; 29:394005. [PMID: 28664870 DOI: 10.1088/1361-648x/aa7ca7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
In a first-principles study based on many-body perturbation theory, we analyze the optical excitations of azobenzene-functionalized self-assembled monolayers (SAMs) with increasing packing density and different terminations, considering for comparison the corresponding gas-phase molecules and dimers. Intermolecular coupling increases with the density of the chromophores independently of the functional groups. The intense [Formula: see text] resonance that triggers photo-isomerization is present in the spectra of isolated dimers and diluted SAMs, but it is almost completely washed out in tightly packed architectures. Intermolecular coupling is partially inhibited by mixing differently functionalized azobenzene derivatives, in particular when large groups are involved. In this way, the excitation band inducing the photo-isomerization process is partially preserved and the effects of dense packing partly counterbalanced. Our results suggest that a tailored design of azobenzene-functionalized SAMs which optimizes the interplay between the packing density of the chromophores and their termination can lead to significant improvements in the photo-switching efficiency of these systems.
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Affiliation(s)
- Caterina Cocchi
- Physics Department and IRIS Adlershof, Humboldt-Universität zu Berlin, Berlin, Germany. European Theoretical Spectroscopic Facility (ETSF
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4
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Synthesis, spectral and computational analysis of 2-(N-bromoalkoxy)-5-(phenylazo)benzaldehydes and their oximes. J Mol Struct 2017. [DOI: 10.1016/j.molstruc.2017.01.018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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5
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McElhinny KM, Huang P, Joo Y, Kanimozhi C, Lakkham A, Sakurai K, Evans PG, Gopalan P. Optically Reconfigurable Monolayer of Azobenzene Donor Molecules on Oxide Surfaces. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:2157-2168. [PMID: 28170273 DOI: 10.1021/acs.langmuir.6b04585] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
The structural configuration of molecules assembled at organic-inorganic interfaces within electronic materials strongly influences the functional electronic and vibrational properties relevant to applications ranging from energy storage to photovoltaics. Controlling and characterizing the structural state of an interface and its evolution under external stimuli is crucial both for the fundamental understanding of the factors influenced by molecular structure and for the development of methods for material synthesis. It has been challenging to create complete molecular monolayers that exhibit external reversible control of the structure and electronic configuration. We report a monolayer/inorganic interface consisting of an organic monolayer assembled on an oxide surface, exhibiting structural and electronic reconfiguration under ultraviolet illumination. The molecular monolayer is linked to the surface through a carboxylate link, with the backbone bearing an azobenzene functional group and the head group consisting of a rhenium-bipyridine group. Optical spectroscopy, X-ray photoelectron spectroscopy, atomic force microscopy, and X-ray reflectivity show that closely packed monolayers are formed from these molecules via the Langmuir-Blodgett technique. Reversible photoisomerization is observed in solution and in monolayers assembled on Si and quartz substrates. The reconfiguration of these monolayers provides additional means to control excitation and charge transfer processes that are important in applications in catalysis, molecular electronics, and solar energy conversion.
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Affiliation(s)
- Kyle M McElhinny
- Department of Materials Science and Engineering, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States
| | - Peishen Huang
- Department of Materials Science and Engineering, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States
| | - Yongho Joo
- Department of Materials Science and Engineering, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States
| | - Catherine Kanimozhi
- Department of Materials Science and Engineering, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States
| | - Arunee Lakkham
- Department of Materials Science and Engineering, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States
| | - Kenji Sakurai
- National Institute for Materials Science , Tsukuba, Ibaraki 305-4007, Japan
- University of Tsukuba , Tsukuba, Ibaraki 305-8577, Japan
| | - Paul G Evans
- Department of Materials Science and Engineering, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States
| | - Padma Gopalan
- Department of Materials Science and Engineering, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States
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6
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Jung U, Kubitschke J, Herges R, Magnussen O. Studies of the molecular switching of azobenzene-functionalized platform adlayers on Au(111) by chronoamperometry. Electrochim Acta 2013. [DOI: 10.1016/j.electacta.2013.06.123] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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7
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Müller M, Jung U, Gusak V, Ulrich S, Holz M, Herges R, Langhammer C, Magnussen O. Localized surface plasmon resonance investigations of photoswitching in azobenzene-functionalized self-assembled monolayers on Au. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:10693-10699. [PMID: 23909478 DOI: 10.1021/la401825f] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Localized plasmon resonance (LSPR) spectroscopy, employing gold nanodisk substrates, is applied for studies of photoswitching in self-assembled monolayers of azobenzene-containing thiols. By choosing customized samples in which the sharp LSPR resonance is well separated from the spectral regime of the molecular absorption bands, the photoisomerization kinetics of the adlayer can be monitored in real time. Quantitative data on the photoinduced trans-cis and cis-trans isomerization processes in inert gas atmosphere were obtained as a function of irradiation intensity and temperature, demonstrating the high sensitivity of this technique to such processes in functional adlayers.
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Affiliation(s)
- Mathias Müller
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, Leibnizstraße 19, 24118 Kiel, Germany
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Manimekalai A, Balachander R. DFT and experimental determination of conformations of 2-(ethoxycarbonylmethoxy)-5-(arylazo)benzaldehydes and their oximes. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2012; 50:765-771. [PMID: 22987368 DOI: 10.1002/mrc.3874] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2012] [Revised: 08/16/2012] [Accepted: 08/27/2012] [Indexed: 06/01/2023]
Abstract
2-(Ethoxycarbonylmethoxy)-5-(arylazo)benzaldehydes 1-4 and their oximes 5-8 were synthesized and characterized by IR, (1)H and (13)C NMR spectroscopy. The favoured conformations of aldehydes 1-4 and oximes 5-8 were predicted theoretically. Selected geometrical parameters and charges were derived from optimized structures. IR, (1)H and (13)C NMR data were also computed using Gaussian-03 package and compared with the observed values. (15)N and (17)O chemical shifts were also determined theoretically.
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Affiliation(s)
- A Manimekalai
- Department of Chemistry, Annamalai University, Annamalainagar 608 002, India.
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9
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Theoretical investigation of the conformation and hydrogen bonding ability of 5-arylazosalicylaldoximes. J Mol Struct 2012. [DOI: 10.1016/j.molstruc.2012.06.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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10
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Jung U, Kuhn S, Cornelissen U, Tuczek F, Strunskus T, Zaporojtchenko V, Kubitschke J, Herges R, Magnussen O. Azobenzene-containing triazatriangulenium adlayers on Au(111): structural and spectroscopic characterization. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:5899-5908. [PMID: 21506548 DOI: 10.1021/la104654p] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Adlayers of different azobenzene-functionalized derivatives of the triazatriangulenium (TATA) platform on Au(111) surfaces were studied by scanning tunneling microscopy (STM), X-ray photoelectron spectroscopy (XPS), gap-mode surface-enhanced Raman spectroscopy (gap-mode SERS), and cyclic voltammetry (CV). The chemical composition of the adlayers is in good agreement with the molecular structure, i.e., different chemical groups attached to the azobenzene functionality were identified. Furthermore, the presence of the azobenzene moieties in the adlayers was verified by the vibration spectra and electrochemical data. These results indicate that the molecules remain intact upon adsorption with the freestanding functional groups oriented perpendicularly to the TATA platform and thus also to the substrate surface.
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Affiliation(s)
- Ulrich Jung
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, Leibnizstr. 19, 24118 Kiel, Germany
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11
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Qi Y, Liu X, Hendriksen BLM, Navarro V, Park JY, Ratera I, Klopp JM, Edder C, Himpsel FJ, Fréchet JMJ, Haller EE, Salmeron M. Influence of molecular ordering on electrical and friction properties of ω-(trans-4-stilbene)alkylthiol self-assembled monolayers on Au(111). LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:16522-16528. [PMID: 20415505 DOI: 10.1021/la100837g] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The electrical and friction properties of ω-(trans-4-stilbene)alkylthiol self-assembled monolayers (SAMs) on Au(111) were investigated using atomic force microscopy (AFM) and near edge X-ray absorption fine structure spectroscopy (NEXAFS). The sample surface was uniformly covered with a molecular film consisting of very small grains. Well-ordered and flat monolayer islands were formed after the sample was heated in nitrogen at 120 °C for 1 h. While lattice resolved AFM images revealed a crystalline phase in the islands, the area between islands showed no order. The islands exhibit substantial reduction (50%) in friction, supporting the existence of good ordering. NEXAFS measurements revealed an average upright molecular orientation in the film, both before and after heating, with a narrower tilt-angle distribution for the heated fim. Conductance-AFM measurements revealed a 2 orders of magnitude higher conductivity on the ordered islands than on the disordered phase. We propose that the conductance enhancement is a result of a better π-π stacking between the trans-stilbene molecular units as a result of improved ordering in islands.
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Affiliation(s)
- Yabing Qi
- Applied Science and Technology Graduate Group, University of California, Berkeley, California 94720, USA
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Jung U, Filinova O, Kuhn S, Zargarani D, Bornholdt C, Herges R, Magnussen O. Photoswitching behavior of azobenzene-containing alkanethiol self-assembled monolayers on Au surfaces. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:13913-13923. [PMID: 20806964 DOI: 10.1021/la1015109] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The photoisomerization of self-assembled monolayers of azobenzene-containing alkanethiols, as well as of mixed monolayers of these substances with n-alkanethiol spacer molecules on Au surfaces, was studied by photoelectrochemical measurements and surface plasmon resonance spectroscopy. A strong dependence on the molecular structure of the adsorbates was found, specifically on the linker between the azobenzene moiety and the alkanethiol: while molecules with an amide group were photoinactive, those with an ether group exhibited pronounced, reversible photoisomerization in pure and mixed adlayers. Both trans-cis and cis-trans isomerization followed first-order kinetics with time constants that suggest high quantum efficiencies for these processes.
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Affiliation(s)
- Ulrich Jung
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, Leibnizstr. 19, 24118 Kiel, Germany
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13
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Muñoz AG, Lewerenz HJ. Advances in Photoelectrocatalysis with Nanotopographical Photoelectrodes. Chemphyschem 2010; 11:1603-15. [DOI: 10.1002/cphc.200900856] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Krakert S, Terfort A. Preparation of Azobenzenealkanethiols for Self-Assembled Monolayers with Photoswitchable Properties. Aust J Chem 2010. [DOI: 10.1071/ch09308] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
A series of azobenzenealkanethiol compounds with the structure p-RC6H4N=NC6H4(CH2)nSH (n = 3, 4) was synthesized using a divergent strategy with the two anilines H2NC6H4(CH2)nSAc as central compounds. This strategy provides fast access to a broad variety of the respective azobenzenethiols without (note!) an oxygen atom in the alkyl chain, thus permitting the self-assembly of these compounds onto gold in a predictable conformation, also taking advantage of the previously found odd–even effect in aromatic–aliphatic hybrid systems. Initial experiments indicate that all of these molecules indeed form dense monolayers, in which the orientation of the azobenzene unit is determined by the number of methylene groups in the aliphatic part of the molecules.
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15
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Switching behavior and optical absorbance of azobenzene-functionalized alkanethiols in different environments. J Photochem Photobiol A Chem 2009. [DOI: 10.1016/j.jphotochem.2009.02.018] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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16
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Griesser T, Adams J, Wappel J, Kern W, Leggett GJ, Trimmel G. Micrometer and nanometer scale patterning using the photo-fries rearrangement: toward selective execution of molecular transformations with nanoscale spatial resolution. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2008; 24:12420-12425. [PMID: 18837527 DOI: 10.1021/la802382p] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The photolithographic modification of monolayers provides a versatile and powerful means of fabricating functionalized nanostructured surfaces. In this contribution, we present photosensitive thiol-bearing aryl ester groups which are capable of undergoing the so-called photo-Fries rearrangement to yield hydroxyketones. Phenyl 16-mercaptohexadecanoate was prepared by a three-step synthesis. This molecule undergoes a photoisomerization reaction upon illumination with UV light at ca. 250 nm. Subsequently this molecule was applied as a self-assembled monolayer on gold. Following photochemical modification, the adsorbates were selectively derivatized to yield amino-functionalized surfaces using a simple two-step reaction. This reaction was monitored by X-ray photoelectron spectroscopy and contact angle measurements and friction force microscopy. Micrometer-scale patterned surfaces were produced using a contact mask in conjunction with a frequency-doubled argon ion laser (lambda=244 nm). Near-field optical exposure was carried out by coupling the laser to a scanning near-field optical microscope and yielded nanometer-scale resolution. Following derivatization, the resulting structures were analyzed by friction force microscopy. Clear contrast was observed in the friction signal following surface modification.
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Affiliation(s)
- Thomas Griesser
- Institute for Chemistry and Technology of Materials (ICTM), Graz University of Technology, Stremayrgasse 16, 8010 Graz, Austria
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Jung U, Baisch B, Kaminski D, Krug K, Elsen A, Weineisen T, Raffa D, Stettner J, Bornholdt C, Herges R, Magnussen O. Structure and redox behavior of azobenzene-containing monolayers on Au(111): A combined STM, X-ray reflectivity, and voltammetry study. J Electroanal Chem (Lausanne) 2008. [DOI: 10.1016/j.jelechem.2008.04.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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18
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Minisini B, Fayet G, Tsobnang F, Bardeau JF. Density functional theory characterisation of 4-hydroxyazobenzene. J Mol Model 2007; 13:1227-35. [PMID: 17917749 DOI: 10.1007/s00894-007-0244-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2007] [Accepted: 09/13/2007] [Indexed: 10/22/2022]
Abstract
We report the structural properties, infrared (IR) and Raman spectra, dipole moment, polarisability, hardness and chemical potential of the trans and cis configurations of 4-hydroxyazobenzene calculated using the B3LYP functionals. All calculations were performed with the following basis sets: 6-31G, 6-31++G, 6-31G(d,p), 6-31++G(d,p), 6-31G(2d,2p), 6-31++G(2d,2p) and 6-311++G(2d,2p). We observed that 6-31++G(d,p) gives similar results to 6-311++G(2d,2p). Consequently, SVWN and PW91 methods were also used in association with 6-31++G(d,p) to test the influence of the different models of exchange and correlation functionals. A planar structure was obtained for all the optimised trans configuration structures. In both isomers, the presence of the hydroxyl group leads to an asymmetry in certain structural parameters. From these results, two IR or Raman active frequencies can be used to easily distinguish trans and cis configurations. The trans configuration was found to be more stable than the cis configuration by 67 +/- 2 kJ mol(-1) at 0 K. The difference of the dipole moment between trans and cis for 4-hydroxyazobenzene was found to be lower than for trans and cis azobenzene.
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Affiliation(s)
- Benoit Minisini
- Institut Supérieur des Matériaux et Mécaniques Avancés du Mans, 44 Av. Bartholdi, 72000, Le Mans, France.
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Abstract
A most appealing feature of the development of (opto)electronic devices based on conjugated organic materials is the highly visible link between fundamental research and technological advances. Improved understanding of organic material properties can often instantly be implemented in novel device architectures, which results in rapid progress in the performance and functionality of devices. An essential ingredient for this success is the strong interdisciplinary nature of the field of organic electronics, which brings together experts in chemistry, physics, and engineering, thus softening or even removing traditional boundaries between the disciplines. Naturally, a thorough comprehension of all properties of organic insulators, semiconductors, and conductors is the goal of current efforts. Furthermore, interfaces between dissimilar materials-organic/organic and organic/inorganic-are inherent in organic electronic devices. It has been recognized that these interfaces are a key for device function and efficiency, and detailed investigations of interface physics and chemistry are at the focus of research. Ultimately, a comprehensive understanding of phenomena at interfaces with organic materials will improve the rational design of highly functional organic electronic devices.
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Affiliation(s)
- Norbert Koch
- Institut für Physik, Humboldt-Universität zu Berlin, Newtonstr. 15, 12489 Berlin, Germany.
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Chukharev V, Vuorinen T, Efimov A, Tkachenko NV, Kimura M, Fukuzumi S, Imahori H, Lemmetyinen H. Photoinduced electron transfer in self-assembled monolayers of porphyrin-fullerene dyads on ITO. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2005; 21:6385-91. [PMID: 15982045 DOI: 10.1021/la0500833] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Two porphyrin-fullerene dyads were synthesized to form self-assembled monolayers (SAMs) on indium-tin oxide (ITO) electrode, with either ITO-porphyrin-fullerene or ITO-fullerene-porphyrin orientations. The dyads contain two linkers for connecting the porphyrin and fullerene moieties and enforcing them essentially to similar geometries of the donor-acceptor pair, and two linkers to ensure the attachment of the dyads to the ITO surface with two desired opposite orientations. The transient photovoltage responses (Maxwell displacement charge) were measured for the dyad films covered by insulating LB films, thus ensuring that the dyads interact only with the ITO electrode. The direction of the electron transfer was from the photoexcited dyad to ITO independent of the dyad orientation. The response amplitude for the ITO-fullerene-porphyrin structure, where the primary intramolecular electron-transfer direction coincides with the direction of the final electron transfer from the dyad to ITO, was 25 times stronger than that for the opposite ITO-porphyrin-fullerene orientation of the dyad. Static photocurrent measurements in a liquid electrochemical cell, however, show only a minor orientation effect, indicating that the photocurrent generation is controlled by the processes at the SAM-liquid interface.
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Affiliation(s)
- Vladimir Chukharev
- Institute of Materials Chemistry, Tampere University of Technology, P.O. Box 541, 33101 Tampere, Finland.
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Jäckel F, Watson MD, Müllen K, Rabe JP. Prototypical single-molecule chemical-field-effect transistor with nanometer-sized gates. PHYSICAL REVIEW LETTERS 2004; 92:188303. [PMID: 15169538 DOI: 10.1103/physrevlett.92.188303] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2003] [Indexed: 05/24/2023]
Abstract
A prototypical single-molecule chemical-field-effect transistor is presented, in which the current through a hybrid-molecular diode is modified by nanometer-sized charge transfer complexes covalently linked to a molecule in an STM junction. The effect is attributed to an interface dipole which shifts the substrate work function by approximately 120 meV. It is induced by the complexes from electron acceptors covalently bound to the molecule in the gap and electron donors coming from the ambient fluid. This proof of principle is regarded as a major step towards monomolecular electronic devices.
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Affiliation(s)
- F Jäckel
- Department of Physics, Humboldt University Berlin, Newtonstrasse 15, 12489 Berlin, Germany
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