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Pattadar D, Arcidiacono A, Beery D, Hanson K, Saavedra SS. Molecular Orientation and Energy Transfer Dynamics of a Metal Oxide Bound Self-Assembled Trilayer. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023; 39:10670-10679. [PMID: 37466635 DOI: 10.1021/acs.langmuir.3c01323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/20/2023]
Abstract
Self-assembly of molecular multilayers via metal ion linkages has become an important strategy for interfacial engineering of metalloid and metal oxide (MOx) substrates, with applications in numerous areas, including energy harvesting, catalysis, and chemical sensing. An important aspect for the rational design of these multilayers is knowledge of the molecular structure-function relationships. For example, in a multilayer composed of different chromophores in each layer, the molecular orientation of each layer, both relative to the adjacent layers and the substrate, influences the efficiency of vectorial energy and electron transfer. Here, we describe an approach using UV-vis attenuated total reflection (ATR) spectroscopy to determine the mean dipole tilt angle of chromophores in each layer in a metal ion-linked trilayer self-assembled on indium-tin oxide. To our knowledge, this is the first report demonstrating the measurement of the orientation of three different chromophores in a single assembly. The ATR approach allows the adsorption of each layer to be monitored in real-time, and any changes in the orientation of an underlying layer arising from the adsorption of an overlying layer can be detected. We also performed transient absorption spectroscopy to monitor interlayer energy transfer dynamics in order to relate structure to function. We found that near unity efficiency, sub-nanosecond energy transfer between the third and second layer was primarily dictated by the distance between the chromophores. Thus, in this case, the orientation had minimal impact at such proximity.
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Affiliation(s)
- Dhruba Pattadar
- Department of Chemistry, University of Arizona, Tucson, Arizona 85721, United States
| | - Ashley Arcidiacono
- Department of Chemistry & Biochemistry, Florida State University, Tallahassee, Florida 32306, United States
| | - Drake Beery
- Department of Chemistry & Biochemistry, Florida State University, Tallahassee, Florida 32306, United States
| | - Kenneth Hanson
- Department of Chemistry & Biochemistry, Florida State University, Tallahassee, Florida 32306, United States
| | - S Scott Saavedra
- Department of Chemistry, University of Arizona, Tucson, Arizona 85721, United States
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2
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Pattadar D, Zheng L, Robb AJ, Beery D, Yang W, Hanson K, Scott Saavedra S. Molecular Orientation of -PO 3H 2 and -COOH Functionalized Dyes on TiO 2, Al 2O 3, ZrO 2, and ITO: A Comparative Study. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2023; 127:2705-2715. [PMID: 36908684 PMCID: PMC9996377 DOI: 10.1021/acs.jpcc.2c08632] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Modification of transparent metal oxide (MOx) surfaces with organic monolayers is widely employed to tailor the properties of interfaces in organic electronic devices, and MOx substrates modified with light-absorbing chromophores are a key component of dye-sensitized solar cells (DSSCs). The effects of an organic modifier on the performance of a MOx-based device are frequently assessed by performing experiments on model monolayer|MOx interfaces, where an "inert" MOx (e.g., Al2O3) is used as a control for an "active" MOx (e.g., TiO2). An underlying assumption in these studies is that the structure of the MOx-monolayer complex is similar between different metal oxides. The validity of this assumption was examined in the present study. Using UV-Vis attenuated total reflection spectroscopy, we measured the mean dipole tilt angle of 4,4'-(anthracene-9,10-diyl)bis(4,1-phenylene)diphosphonic acid (A1P) adsorbed on indium tin oxide (ITO), TiO2, ZrO2, and Al2O3. When the surface roughness of the MOx substrate and the surface coverage (𝛤) of the A1P film were constant, the molecular orientation of A1P was the same on these substrates. The study was extended to 4,4'-(anthracene-9,10-diyl)bis(4,1-phenylene)dicarboxylic acid (A1C) adsorbed on the same group of MOx substrates. The mean tilt angle of A1C and A1P films on ITO was the same, which is likely due the intermolecular interactions resulting from the high and approximately equal 𝛤 of both films. Comparing A1C films at the same 𝛤 on TiO2 and Al2O3 having the same surface roughness, there was no difference in the mean tilt angle. MD simulations of A1C and A1P on TiO2 produced nearly identical tilt angle distributions, which supports the experimental findings. This study provides first experimental support for the assumption that the structure of the MOx-modifer film is the same on an "active" substrate vs. a "inert" control substrate.
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Affiliation(s)
- Dhruba Pattadar
- Department of Chemistry & Biochemistry, University of Arizona, Tucson, Arizona 85721, USA
| | - Lianqing Zheng
- Institute of Molecular Biophysics, Florida State University, Tallahassee, Florida 32306, USA
| | - Alex J. Robb
- Department of Chemistry & Biochemistry, Florida State University, Tallahassee, Florida 32306, USA
| | - Drake Beery
- Department of Chemistry & Biochemistry, Florida State University, Tallahassee, Florida 32306, USA
| | - Wei Yang
- Institute of Molecular Biophysics, Florida State University, Tallahassee, Florida 32306, USA
- Department of Chemistry & Biochemistry, Florida State University, Tallahassee, Florida 32306, USA
| | - Kenneth Hanson
- Department of Chemistry & Biochemistry, Florida State University, Tallahassee, Florida 32306, USA
| | - S. Scott Saavedra
- Department of Chemistry & Biochemistry, University of Arizona, Tucson, Arizona 85721, USA
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3
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Marcon RO, Bonvent JJ, Brochsztain S. Radical Anions and Dianions of Naphthalenediimides Generated within Layer-by-Layer Zirconium Phosphonate Thin Films. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:2153-2161. [PMID: 35104410 DOI: 10.1021/acs.langmuir.1c03337] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Chemical reduction of N,N'-bis(2-phosphonoethyl)-1,4,5,8-naphthalenediimide (PNDI) with the reducing agent sodium dithionite gave stable colored reduced species, both in homogeneous solutions and in self-assembled thin films. When colorless PNDI aqueous solutions were titrated with the reducing agent, stepwise reduction was observed, giving first the radical anion (PNDI-•) and then the dianion (PNDI2-) species, which were detected by UV-visible-NIR spectroscopy, allowing the unambiguous determination of absorption maxima and molar absorptivities for each species. The radical anion PNDI-• was found to form π-dimers in water, but monomeric PNDI-• was formed in the presence of the cationic surfactant cetyltrimethylammonium bromide, indicating association with the micelles. Thin films of PNDI with 25 layers were grown by the zirconium phosphonate method on quartz substrates. Reduction of the films with sodium dithionite also produced radical anions and dianions of PNDI. However, reduction in the films was much slower than in solution, evidencing the compactness of the films. Moreover, reduction in the films did not proceed to completion, even with excess of the reducing agent, which can be attributed to the repulsion of negative charges within the film.
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Affiliation(s)
- Rodrigo Oliveira Marcon
- Universidade de Mogi das Cruzes, AV. Dr. Candido Xavier de Almeida Souza 200, 08780-911 Mogi das Cruzes, Brazil
| | - Jean-Jacques Bonvent
- Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, 09210-170 Santo André, Brazil
| | - Sergio Brochsztain
- Centro de Engenharia, Modelagem e Ciências Sociais Aplicadas, Universidade Federal do ABC, Avenida dos Estados, 5001, 09210-170 Santo André, Brazil
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4
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Arcidiacono A, Zhou Y, Zhang W, Ellison JO, Ayad S, Knorr ES, Peters AN, Zheng L, Yang W, Saavedra SS, Hanson K. Examining the influence of bilayer structure on energy transfer and molecular photon upconversion in metal ion linked multilayers. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2020; 124:23597-23610. [PMID: 33354274 PMCID: PMC7750814 DOI: 10.1021/acs.jpcc.0c08715] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Metal ion linked multilayers is a unique motif to spatially control and geometrically restrict molecules on a metal oxide surface and is of interest in a number of promising applications. Here we use a bilayer composed of a metal oxide surface, an anthracene annihilator molecule, Zn(II) linking ion, and porphyrin sensitizers to probe the influence of the position of the metal ion binding site on energy transfer, photon upconversion, and photocurrent generation. Despite being energetically similar, varying the position of the carboxy metal ion binding group (i.e. ortho, meta, para) of the Pt(II) tetraphenyl porphyrin sensitizer had a large impact on energy transfer rates and upconverted photocurrent that can be attributed to differences in their geometries. From polarized attenuated total reflectance measurements of the bilayers on ITO, we found that the orientation of the first layer (anthracene) was largely unperturbed by subsequent layers. However, the tilt angle of the porphyrin plane varies dramatically from 41° to 64° to 57° for the para-, meta-, and ortho-COOH substituted porphyrin molecules, which is likely responsible for the variation in energy transfer rates. We go on to show using molecular dynamics simulations that there is considerable flexibility in porphyrin orientation, indicating that an average structure is insufficient to predict the ensemble behavior. Instead, even a small subset of the population with highly favorable energy transfer rates can be the primary driver in increasing the likelihood of energy transfer. Gaining control of the orientation and its distribution will be a critical step in maximizing the potential of the metal ion linked structures.
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Affiliation(s)
- Ashley Arcidiacono
- Department of Chemistry & Biochemistry, Florida State University, Tallahassee, Florida 32306, USA
| | - Yan Zhou
- Department of Chemistry & Biochemistry, Florida State University, Tallahassee, Florida 32306, USA
| | - Wendi Zhang
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona 85721, USA
| | - Jeffrey O. Ellison
- Department of Chemistry & Biochemistry, Florida State University, Tallahassee, Florida 32306, USA
| | - Suliman Ayad
- Department of Chemistry & Biochemistry, Florida State University, Tallahassee, Florida 32306, USA
| | - Erica S. Knorr
- Department of Chemistry & Biochemistry, Florida State University, Tallahassee, Florida 32306, USA
| | - Autumn N. Peters
- Department of Chemistry & Biochemistry, Florida State University, Tallahassee, Florida 32306, USA
| | - Lianqing Zheng
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306, USA
| | - Wei Yang
- Department of Chemistry & Biochemistry, Florida State University, Tallahassee, Florida 32306, USA
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306, USA
| | - S. Scott Saavedra
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona 85721, USA
| | - Kenneth Hanson
- Department of Chemistry & Biochemistry, Florida State University, Tallahassee, Florida 32306, USA
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5
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Zheng Y, Giordano AJ, Marder SR, Saavedra SS. Potential-Modulated Total Internal Reflection Fluorescence for Measurement of the Electron Transfer Kinetics of Submonolayers on Optically Transparent Electrodes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:6728-6735. [PMID: 32453577 DOI: 10.1021/acs.langmuir.0c00817] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
An electroreflectance method to determine the electron transfer rate constant of a film of redox-active chromophores immobilized on an optically transparent electrode when the surface coverage of the film is very low (<0.1 monolayer) is described herein. The method, potential-modulated total internal reflection fluorescence (PM-TIRF) spectroscopy, is a fluorescence version of potential-modulated attenuated total reflection (PM-ATR) spectroscopy that is applicable when the immobilized chromophores are luminescent. The method was tested using perylene diimide (PDI) molecules functionalized with p-phenylene phosphonic acid (PA) moieties that bind strongly to indium-tin oxide (ITO). Conditions to prepare PDI-phenyl-PA films that exhibit absorbance and fluorescence spectra characteristic of monomeric (i.e., nonaggregated) molecules were identified; the electrochemical surface coverage was approximately 0.03 monolayer. The tilt angle of the long axis of the PDI molecular plane is 58° relative to the ITO surface normal, 25° greater than the tilt angle of aggregated PDI-phenyl-PA films, which have a surface coverage of approximately one monolayer. The more in-plane orientation of monomeric films is likely due to the absence of cofacial π-π interactions present in aggregated films and possibly a difference in PA-ITO binding modes. The electron transfer rate constant (ks,opt) of monomeric PDI-phenyl-PA films was determined using PM-TIRF and compared with PM-ATR results obtained for aggregated films. For PDI monomers, ks,opt = 3.8 × 103 s-1, which is about 3.7-fold less than ks,opt for aggregated films. The slower kinetics are attributed to the absence of electron self-exchange between monomeric PDI molecules. Differences in the electroactivity of the binding sites on the ITO electrode surface also may play a role. This is the first demonstration of PM-TIRF for determining electron transfer rate constants at an electrode/organic film interface.
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Affiliation(s)
- Yilong Zheng
- Department of Chemistry & Biochemistry, University of Arizona, Tucson, Arizona 85721, United States
| | - Anthony J Giordano
- School of Chemistry & Biochemistry and the Center for Organic Photonics and Electronics, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Seth R Marder
- School of Chemistry & Biochemistry and the Center for Organic Photonics and Electronics, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - S Scott Saavedra
- Department of Chemistry & Biochemistry, University of Arizona, Tucson, Arizona 85721, United States
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6
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Bertram M, Schuschke C, Waidhas F, Schwarz M, Hohner C, Montero MA, Brummel O, Libuda J. Molecular anchoring to oxide surfaces in ultrahigh vacuum and in aqueous electrolytes: phosphonic acids on atomically-defined cobalt oxide. Phys Chem Chem Phys 2019; 21:23364-23374. [PMID: 31637373 DOI: 10.1039/c9cp03779a] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
In this work, we investigated the interaction of phenylphosphonic acid (PPA, C6H5PO3H2) with atomically-defined Co3O4(111) thin films, grown on Ir(100), under ultrahigh vacuum (UHV) conditions and in the electrochemical environment. In the first step, we employed infrared reflection absorption spectroscopy (IRAS) and followed the formation of a saturated monolayer (380 K) in UHV. We observed that the binding motif changes from a chelating tridentate in the sub-monolayer regime to a chelating bidentate at full monolayer coverages. In the electrochemical environment, we analyzed the interaction of PPA with the same Co3O4(111) surface by electrochemical infrared reflection absorption spectroscopy (EC-IRRAS) (0.3 VRHE-1.3 VRHE). When adsorbed at pH 10 from an ammonia buffered aqueous solution, PPA binds to the surface in form of a fully deprotonated chelating bidentate. With increasing electrode potential, we observed two fully reversible processes. At low buffer concentration, protons are released upon oxidation of surface Co2+ ions and lead to protonation of the anchored phosphonates. At high buffer concentration, most of the protons released are accepted by NH3. Simultaneously, the surface phosphonate changes its adsorption motif from bidentate to tridentate while adopting a more upright geometry.
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Affiliation(s)
- Manon Bertram
- Interface Research and Catalysis, Erlangen Catalysis Resource Center, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstraße 3, D-91058 Erlangen, Germany.
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7
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Ehamparam R, Oquendo LE, Liao MW, Brynnel AK, Ou KL, Armstrong NR, McGrath DV, Saavedra SS. Axially Bound Ruthenium Phthalocyanine Monolayers on Indium Tin Oxide: Structure, Energetics, and Charge Transfer Properties. ACS APPLIED MATERIALS & INTERFACES 2017; 9:29213-29223. [PMID: 28795562 DOI: 10.1021/acsami.7b07394] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The efficiency of charge collection at the organic/transparent conducting oxide (TCO) interface in organic photovoltaic (OPV) devices affects overall device efficiency. Modifying the TCO with an electrochemically active molecule may enhance OPV efficiency by providing a charge-transfer pathway between the electrode and the organic active layer, and may also mitigate surface recombination. The synthesis and characterization of phosphonic acid-ruthenium phthalocyanine (RuPcPA) monolayer films on indium tin oxide (ITO), designed to facilitate charge harvesting at ITO electrodes, is presented in this work. The PA group was installed axially relative to the Pc plane so that upon deposition, RuPcPA molecules were preferentially aligned with the ITO surface plane. The tilt angle of 22° between the normal axes to the Pc plane and the ITO surface plane, measured by attenuated total reflectance (ATR) spectroscopy, is consistent with a predominately in-plane orientation. The effect of surface roughness on RuPcPA orientation was modeled, and a correlation was obtained between experimental and theoretical mean tilt angles. Based on electrochemical and spectroelectrochemical studies, RuPcPA monolayers are composed predominately of monomers. Electrochemical impedance spectroscopy (EIS) and potential modulated-ATR (PM-ATR) spectroscopy were used to characterize the electron-transfer (ET) kinetics of these monolayers. A rate constant of 4.0 × 103 s-1 was measured using EIS, consistent with a short tunneling distance between the chromophore and the electrode surface. Using PM-ATR, ks,opt values of 2.2 × 103 and 2.4 × 103 s-1 were measured using TE and TM polarized light, respectively; the similarity of these values is consistent with a narrow molecular orientation distribution and narrow range of tunneling distances. The ionization potential of RuPcPA-modified ITO was measured using ultraviolet photoelectron spectroscopy and the results indicate favorable energetics for hole collection at the RuPcPA/ITO interface, indicating that this type of TCO modification may be useful for enhancing charge collection efficiency in OPV devices.
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Affiliation(s)
- Ramanan Ehamparam
- Department of Chemistry and Biochemistry, University of Arizona , Tucson, Arizona 85721, United States
| | - Luis E Oquendo
- Department of Chemistry and Biochemistry, University of Arizona , Tucson, Arizona 85721, United States
| | - Michael W Liao
- Department of Chemistry and Biochemistry, University of Arizona , Tucson, Arizona 85721, United States
| | - Ambjorn K Brynnel
- Department of Chemistry and Biochemistry, University of Arizona , Tucson, Arizona 85721, United States
| | - Kai-Lin Ou
- Department of Chemistry and Biochemistry, University of Arizona , Tucson, Arizona 85721, United States
| | - Neal R Armstrong
- Department of Chemistry and Biochemistry, University of Arizona , Tucson, Arizona 85721, United States
| | - Dominic V McGrath
- Department of Chemistry and Biochemistry, University of Arizona , Tucson, Arizona 85721, United States
| | - S Scott Saavedra
- Department of Chemistry and Biochemistry, University of Arizona , Tucson, Arizona 85721, United States
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8
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Shallcross RC, Zheng Y, Saavedra SS, Armstrong NR. Determining Band-Edge Energies and Morphology-Dependent Stability of Formamidinium Lead Perovskite Films Using Spectroelectrochemistry and Photoelectron Spectroscopy. J Am Chem Soc 2017; 139:4866-4878. [DOI: 10.1021/jacs.7b00516] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- R. Clayton Shallcross
- Department of Chemistry and
Biochemistry, University of Arizona, Tucson, Arizona 85721, United States
| | - Yilong Zheng
- Department of Chemistry and
Biochemistry, University of Arizona, Tucson, Arizona 85721, United States
| | - S. Scott Saavedra
- Department of Chemistry and
Biochemistry, University of Arizona, Tucson, Arizona 85721, United States
| | - Neal R. Armstrong
- Department of Chemistry and
Biochemistry, University of Arizona, Tucson, Arizona 85721, United States
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9
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ZHENG Y, SAAVEDRA SS. Characterization of Charge-Transfer Kinetics at Organic/Electrode Interfaces Using Potential-modulated Attenuated Total Reflectance (PM-ATR) Spectroscopy. ANAL SCI 2017; 33:427-433. [DOI: 10.2116/analsci.33.427] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Yilong ZHENG
- Department of Chemistry & Biochemistry, University of Arizona
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10
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Zheng Y, Jradi FM, Parker TC, Barlow S, Marder SR, Saavedra SS. Influence of Molecular Aggregation on Electron Transfer at the Perylene Diimide/Indium-Tin Oxide Interface. ACS APPLIED MATERIALS & INTERFACES 2016; 8:34089-34097. [PMID: 27960436 DOI: 10.1021/acsami.6b10731] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Chemisorption of an organic monolayer to tune the surface properties of a transparent conductive oxide (TCO) electrode can improve the performance of organic electronic devices that rely on efficient charge transfer between an organic active layer and a TCO contact. Here, a series of perylene diimides (PDIs) was synthesized and used to study relationships between monolayer structure/properties and electron transfer kinetics at PDI-modified indium-tin oxide (ITO) electrodes. In these PDI molecules, one of the imide substituents is a benzene ring bearing a phosphonic acid (PA) and the other is a bulky aryl group that is twisted out of the plane of the PDI core. The size of the bulky aryl group and the substitution of the benzene ring bearing the PA were both varied, which altered the extent of aggregation when these molecules were absorbed as monolayer films (MLs) on ITO, as revealed by both attenuated total reflectance (ATR) and total internal reflection fluorescence spectra. Polarized ATR measurements indicate that, in these MLs, the long axis of the PDI core is tilted at an angle of 33-42° relative to the surface normal; the tilt angle increased as the degree of bulky substitution increased. Rate constants for electron transfer (ks,opt) between these redox-active modifiers and ITO were determined by potential-modulated ATR spectroscopy. As the degree of PDI aggregation was reduced, ks,opt declined, which is attributed to a reduction in the lateral electron self-exchange rate between adsorbed PDI molecules, as well as the heterogeneous conductivity of the ITO electrode surface. Photoelectrochemical measurements using a dissolved aluminum phthalocyanine as an electron donor showed that ITO modified with any of these PDIs is a more effective electron-collecting electrode than bare ITO.
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Affiliation(s)
- Yilong Zheng
- Department of Chemistry & Biochemistry, University of Arizona , Tucson, Arizona 85721-00041, United States
| | - Fadi M Jradi
- School of Chemistry & Biochemistry and the Center for Organic Photonics and Electronics, Georgia Institute of Technology , Atlanta, Georgia 30332-0400, United States
| | - Timothy C Parker
- School of Chemistry & Biochemistry and the Center for Organic Photonics and Electronics, Georgia Institute of Technology , Atlanta, Georgia 30332-0400, United States
| | - Stephen Barlow
- School of Chemistry & Biochemistry and the Center for Organic Photonics and Electronics, Georgia Institute of Technology , Atlanta, Georgia 30332-0400, United States
| | - Seth R Marder
- School of Chemistry & Biochemistry and the Center for Organic Photonics and Electronics, Georgia Institute of Technology , Atlanta, Georgia 30332-0400, United States
| | - S Scott Saavedra
- Department of Chemistry & Biochemistry, University of Arizona , Tucson, Arizona 85721-00041, United States
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11
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Peverari CR, David-Parra DN, Barsan MM, Teixeira MF. Mechanistic study of the formation of multiblock π-conjugated metallopolymer. Polyhedron 2016. [DOI: 10.1016/j.poly.2016.06.021] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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12
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Paniagua SA, Giordano AJ, Smith OL, Barlow S, Li H, Armstrong NR, Pemberton JE, Brédas JL, Ginger D, Marder SR. Phosphonic Acids for Interfacial Engineering of Transparent Conductive Oxides. Chem Rev 2016; 116:7117-58. [DOI: 10.1021/acs.chemrev.6b00061] [Citation(s) in RCA: 142] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Sergio A. Paniagua
- School
of Chemistry and Biochemistry and Center for Organic Photonics and
Electronics, Georgia Institute of Technology, Atlanta, Georgia 30332-0400, United States
| | - Anthony J. Giordano
- School
of Chemistry and Biochemistry and Center for Organic Photonics and
Electronics, Georgia Institute of Technology, Atlanta, Georgia 30332-0400, United States
| | - O’Neil L. Smith
- School
of Chemistry and Biochemistry and Center for Organic Photonics and
Electronics, Georgia Institute of Technology, Atlanta, Georgia 30332-0400, United States
| | - Stephen Barlow
- School
of Chemistry and Biochemistry and Center for Organic Photonics and
Electronics, Georgia Institute of Technology, Atlanta, Georgia 30332-0400, United States
| | - Hong Li
- School
of Chemistry and Biochemistry and Center for Organic Photonics and
Electronics, Georgia Institute of Technology, Atlanta, Georgia 30332-0400, United States
- Division
of Physical Sciences and Engineering, King Abdullah University of Science and Technology, KAUST, Thuwal 23955-6900, Kingdom of Saudi Arabia
| | - Neal R. Armstrong
- Department
of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona 85721, United States
| | - Jeanne E. Pemberton
- Department
of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona 85721, United States
| | - Jean-Luc Brédas
- School
of Chemistry and Biochemistry and Center for Organic Photonics and
Electronics, Georgia Institute of Technology, Atlanta, Georgia 30332-0400, United States
- Division
of Physical Sciences and Engineering, King Abdullah University of Science and Technology, KAUST, Thuwal 23955-6900, Kingdom of Saudi Arabia
| | - David Ginger
- Department
of Chemistry, University of Washington, Seattle, Washington 98195, United States
| | - Seth R. Marder
- School
of Chemistry and Biochemistry and Center for Organic Photonics and
Electronics, Georgia Institute of Technology, Atlanta, Georgia 30332-0400, United States
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13
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Modification of alkyne-functionalized asymmetric phthalocyanines by CuI-catalyzed azide-alkyne cycloaddition. Tetrahedron 2015. [DOI: 10.1016/j.tet.2015.09.074] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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14
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Ehamparam R, Pavlopoulos NG, Liao MW, Hill LJ, Armstrong NR, Pyun J, Saavedra SS. Band Edge Energetics of Heterostructured Nanorods: Photoemission Spectroscopy and Waveguide Spectroelectrochemistry of Au-Tipped CdSe Nanorod Monolayers. ACS NANO 2015; 9:8786-800. [PMID: 26291717 DOI: 10.1021/acsnano.5b01720] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Conduction and valence band energies (ECB, EVB) for CdSe nanorods (NRs) functionalized with Au nanoparticle (NP) tips are reported here, referenced to the vacuum scale. We use (a) UV photoemission spectroscopy (UPS) to measure EVB for NR films, utilizing advanced approaches to secondary electron background correction, satellite removal to enhance spectral contrast, and correction for shifts in local vacuum levels; and (b) waveguide-based spectroelectrochemistry to measure ECB from onset potentials for electron injection into NR films tethered to ITO. For untipped CdSe NRs, both approaches show EVB = 5.9-6.1 eV and ECB = 4.1-4.3 eV. Addition of Au tips alters the NR band edge energies and introduces midgap states, in ways that are predicted to influence the efficiency of these nanomaterials as photoelectrocatalysts. UPS results show that Au tipping shifts EVB closer to vacuum by up to 0.4 eV, shifts the apparent Fermi energy toward the middle of the band gap, and introduces additional states above EVB. Spectroelectrochemical results confirm these trends: Au tipping shifts ECB closer to vacuum, by 0.4-0.6 eV, and introduces midgap states below ECB, which are assigned as metal-semiconductor interface (MSI) states. Characterization of these band edge energies and understanding the origins of MSI states is needed to design energy conversion systems with proper band alignment between the light absorbing NR, the NP catalyst, and solution electron donors and acceptors. The complementary characterization protocols presented here should be applicable to a wide variety of thin films of heterogeneous photoactive nanomaterials, aiding in the identification of the most promising material combinations for photoelectrochemical energy conversion.
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Affiliation(s)
- Ramanan Ehamparam
- Department of Chemistry and Biochemistry, University of Arizona , Tucson, Arizona 85721, United States
| | - Nicholas G Pavlopoulos
- Department of Chemistry and Biochemistry, University of Arizona , Tucson, Arizona 85721, United States
| | - Michael W Liao
- Department of Chemistry and Biochemistry, University of Arizona , Tucson, Arizona 85721, United States
| | - Lawrence J Hill
- Department of Chemistry and Biochemistry, University of Arizona , Tucson, Arizona 85721, United States
| | - Neal R Armstrong
- Department of Chemistry and Biochemistry, University of Arizona , Tucson, Arizona 85721, United States
| | - Jeffrey Pyun
- Department of Chemistry and Biochemistry, University of Arizona , Tucson, Arizona 85721, United States
- World Class University Program for Chemical Convergence for Energy and Environment, School of Chemical and Biological Engineering, Seoul National University , Seoul 151-744, Korea
| | - S Scott Saavedra
- Department of Chemistry and Biochemistry, University of Arizona , Tucson, Arizona 85721, United States
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Morlanés N, Joya KS, Takanabe K, Rodionov V. Perfluorinated Cobalt Phthalocyanine Effectively Catalyzes Water Electrooxidation. Eur J Inorg Chem 2014. [DOI: 10.1002/ejic.201403015] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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16
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Çakır V, Kantekin H, Bıyıklıoğlu Z, Koca A. Synthesis, electrochemistry, spectroelectrochemistry and electropolymerization of metal-free and metallophthalocyanines. Polyhedron 2014. [DOI: 10.1016/j.poly.2014.07.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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17
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Si L, He H. Porphyrin Dyes on TiO2 Surfaces with Different Orientations: A Photophysical, Photovoltaic, and Theoretical Investigation. J Phys Chem A 2014; 118:3410-8. [DOI: 10.1021/jp412609k] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- Liping Si
- Department of Chemistry, Eastern Illinois University, Charleston, Illinois 61920, United States
- Center for Advanced Photovoltaics, South Dakota State University, Brookings, South Dakota 57006, United States
| | - Hongshan He
- Department of Chemistry, Eastern Illinois University, Charleston, Illinois 61920, United States
- Center for Advanced Photovoltaics, South Dakota State University, Brookings, South Dakota 57006, United States
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Negrimovsky V, Komissarov A, Perepukhov A, Suponitsky K, Perevalov V, Lukyanets E. Phthalocyanines with phosphonate moiety viaC-nucleophilic substitution in phthalonitriles. J PORPHYR PHTHALOCYA 2013. [DOI: 10.1142/s108842461350051x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Interaction of isomeric 4-nitro- or 3-nitrophthalonitrile with triethyl phosphonoacetate, diethyl cyanomethylphosphonate or tetraethyl methylenediphosphonate in basic conditions resulted in regioselective C -nucleophilic oxidative substitution of hydrogen ortho-located to nitro group, new phthalonitriles with diethoxyphosphorylmethyl or bis(diethoxyphosphoryl)methyl group were isolated in modest yields. In the same conditions one chlorine atom of tetrachlorophthalonitrile was regioselectively substituted with triethyl phosphonoacetate. In basic conditions, both parent phthalonitriles and corresponding zinc phthalocyanines with ortho-located nitro and diethoxyphosphoryl substituted methyl groups are involved in reversible acid-base interaction accompanied with large bathochromic shift of their long wavelength absorption maxima in visible or NIR region, correspondingly. Formation of tetraazachlorin- and tetraaza(iso)bacteriochlorin-like anions is proposed for explanation of this unprecedent bathochromic shift for phthalocyanines.
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Affiliation(s)
- Vladimir Negrimovsky
- Organic Intermediates and Dyes Institute, B. Sadovaya 1/4, Moscow 123995, Russia
| | - Aleksey Komissarov
- Organic Intermediates and Dyes Institute, B. Sadovaya 1/4, Moscow 123995, Russia
| | - Alexandr Perepukhov
- Moscow Institute of Physics and Technology, Institutskii pereulok 9, Dolgoprudny 141700, Russia
| | - Kyrill Suponitsky
- A.N. Nesmeyanov Institute of Organoelement Compounds, Vavilov str. 28, Moscow 119991, Russia
| | - Valery Perevalov
- Mendeleev University of Chemical Technology of Russia, Miusskaya sq. 9, Moscow 125047, Russia
| | - Evgeny Lukyanets
- Organic Intermediates and Dyes Institute, B. Sadovaya 1/4, Moscow 123995, Russia
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Guerrero G, Alauzun JG, Granier M, Laurencin D, Mutin PH. Phosphonate coupling molecules for the control of surface/interface properties and the synthesis of nanomaterials. Dalton Trans 2013; 42:12569-85. [DOI: 10.1039/c3dt51193f] [Citation(s) in RCA: 172] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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