1
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Qi L, Mayall RM, Lee DS, Smith C, Woods A, Narouz MR, Hyla A, Bhattacharjee H, She Z, Crudden CM, Birss VI. Energetics and Redox Kinetics of Pure Ferrocene-Terminated N-Heterocyclic Carbene Self-Assembled Monolayers on Gold. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2024; 40:17367-17377. [PMID: 39106183 DOI: 10.1021/acs.langmuir.4c01446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/09/2024]
Abstract
N-heterocyclic carbene (NHC) self-assembled monolayers (SAMs) on gold have received considerable attention, but little is known about the lateral interactions between neighboring NHC molecules, their stability when subjected to aggressive oxidizing/reducing conditions, and their interactions with solution ions, all of which are essential for their use in a wide range of applications. To address these deficiencies, we present a comprehensive investigation of two different ferrocene (Fc)-terminated NHC SAMs with different chain lengths and linking groups. Pure monolayers of Fc-terminated NHCs display only a single, symmetrical pair of redox peaks, implying the formation of a homogeneous SAM structure with uniformly distributed Fc/Fc+ redox centers. By comparison, pure Fc-alkylthiol SAMs exhibit complex and impractical redox chemistry and require surface dilution in order to achieve reproducible properties. The NHC SAMs examined in this study exhibit very fast Fc redox kinetics and comparable or even superior stability against the application of multiple potential cycles or long-time holding at constant potential compared to alkylthiol SAMs. Furthermore, ion pairing of Fc+ and hydrophobic perchlorate and other hydrophilic anions is observed with Fc-NHC SAMs, highlighting conditions favorable for future applications of these monolayers. This study should therefore shed light on the very promising characteristics of redox-active NHC SAMs as an alternative to traditional Fc-alkylthiol SAMs for multiple practical applications, including in sensors and electrocatalysis.
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Affiliation(s)
- Lin Qi
- Department of Chemistry, University of Calgary, Calgary, Alberta T2N1N4, Canada
| | - Robert M Mayall
- Department of Chemistry, University of Calgary, Calgary, Alberta T2N1N4, Canada
| | - Dianne S Lee
- Department of Chemistry, Queen's University, Kingston, Ontario K7L3N6, Canada
| | - Christene Smith
- Department of Chemistry, Queen's University, Kingston, Ontario K7L3N6, Canada
| | - April Woods
- Department of Chemistry, University of Calgary, Calgary, Alberta T2N1N4, Canada
| | - Mina R Narouz
- Department of Chemistry, Queen's University, Kingston, Ontario K7L3N6, Canada
| | - Alexander Hyla
- Department of Chemistry, University of Calgary, Calgary, Alberta T2N1N4, Canada
| | | | - Zhe She
- Department of Chemistry, Queen's University, Kingston, Ontario K7L3N6, Canada
| | - Cathleen M Crudden
- Department of Chemistry, Queen's University, Kingston, Ontario K7L3N6, Canada
| | - Viola Ingrid Birss
- Department of Chemistry, University of Calgary, Calgary, Alberta T2N1N4, Canada
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2
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Cegiełka D, Frey M, Kozieł K, Neumann C, Turchanin A, Cyganik P. Electron-Beam-Induced Modification of N-Heterocyclic Carbenes: Carbon Nanomembrane Formation. J Phys Chem Lett 2024; 15:8196-8204. [PMID: 39094029 PMCID: PMC11331524 DOI: 10.1021/acs.jpclett.4c01705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2024] [Revised: 07/13/2024] [Accepted: 07/30/2024] [Indexed: 08/04/2024]
Abstract
Electron irradiation of self-assembled monolayers (SAMs) is a versatile tool for lithographic methods and the formation of new 2D materials such as carbon nanomembranes (CNMs). While the interaction between the electron beam and standard thiolate SAMs has been well studied, the effect of electron irradiation for chemically and thermally ultrastable N-heterocyclic carbenes (NHCs) remains unknown. Here we analyze electron irradiation of NHC SAMs featuring different numbers of benzene moieties and different sizes of the nitrogen side groups to modify their structure. Our results provide design rules to optimize NHC SAMs for effective electron-beam modification that includes the formation of sulfur-free CNMs, which are more suitable for ultrafiltration applications. Considering that NHC monolayers exhibit up to 100 times higher stability of their bonding with the metal substrate toward electron-irradiation compared to standard SAMs, they offer a new alternative for chemical lithography where structural modification of SAMs should be limited to the functional group.
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Affiliation(s)
- Daria
M. Cegiełka
- Jagiellonian
University, Faculty of Physics,
Astronomy and Applied Computer Science, Smoluchowski Institute of
Physics, Łojasiewicza
11, 30-348 Krakow, Poland
- Jagiellonian
University, Doctoral School of Exact and
Natural Sciences, Łojasiewicza
11, 30-348 Krakow, Poland
| | - Martha Frey
- Institute
of Physical Chemistry, Friedrich Schiller
University Jena, Lessingstraße 10, 07743 Jena, Germany
| | - Krzysztof Kozieł
- Faculty
of Chemistry, Jagiellonian University, 30-387 Krakow, Poland
| | - Christof Neumann
- Institute
of Physical Chemistry, Friedrich Schiller
University Jena, Lessingstraße 10, 07743 Jena, Germany
| | - Andrey Turchanin
- Institute
of Physical Chemistry, Friedrich Schiller
University Jena, Lessingstraße 10, 07743 Jena, Germany
- Jena
Center for Soft Matter, 07743 Jena, Germany
| | - Piotr Cyganik
- Jagiellonian
University, Faculty of Physics,
Astronomy and Applied Computer Science, Smoluchowski Institute of
Physics, Łojasiewicza
11, 30-348 Krakow, Poland
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3
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Palasz JM, Long Z, Meng J, Videla PE, Kelly HR, Lian T, Batista VS, Kubiak CP. A Resilient Platform for the Discrete Functionalization of Gold Surfaces Based on N-Heterocyclic Carbene Self-Assembled Monolayers. J Am Chem Soc 2024; 146:10489-10497. [PMID: 38584354 DOI: 10.1021/jacs.3c14113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/09/2024]
Abstract
We describe the synthesis and characterization of a versatile platform for gold functionalization, based on self-assembled monolayers (SAMs) of distal-pyridine-functionalized N-heterocyclic carbenes (NHC) derived from bis(NHC) Au(I) complexes. The SAMs are characterized using polarization-modulation infrared reflectance-absorption spectroscopy, surface-enhanced Raman spectroscopy, and X-ray photoelectron spectroscopy. The binding mode is examined computationally using density functional theory, including calculations of vibrational spectra and direct comparisons to the experimental spectroscopic signatures of the monolayers. Our joint computational and experimental analyses provide structural information about the SAM binding geometries under ambient conditions. Additionally, we examine the reactivity of the pyridine-functionalized SAMs toward H2SO4 and W(CO)5(THF) and verify the preservation of the introduced functionality at the interface. Our results demonstrate the versatility of N-heterocyclic carbenes as robust platforms for on-surface acid-base and ligand exchange reactions.
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Affiliation(s)
- Joseph M Palasz
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, MC 0358, La Jolla, California 92093, United States
| | - Zhuoran Long
- Department of Chemistry and Energy Sciences Institute, Yale University, 225 Prospect Street, New Haven, Connecticut 06520, United States
| | - Jinhui Meng
- Department of Chemistry, Emory University, 1515 Dickey Drive Northeast, Atlanta, Georgia 30322, United States
| | - Pablo E Videla
- Department of Chemistry and Energy Sciences Institute, Yale University, 225 Prospect Street, New Haven, Connecticut 06520, United States
| | - H Ray Kelly
- Department of Chemistry and Energy Sciences Institute, Yale University, 225 Prospect Street, New Haven, Connecticut 06520, United States
| | - Tianquan Lian
- Department of Chemistry, Emory University, 1515 Dickey Drive Northeast, Atlanta, Georgia 30322, United States
| | - Victor S Batista
- Department of Chemistry and Energy Sciences Institute, Yale University, 225 Prospect Street, New Haven, Connecticut 06520, United States
| | - Clifford P Kubiak
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, MC 0358, La Jolla, California 92093, United States
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4
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Ren J, Das M, Osthues H, Nyenhuis M, Schulze Lammers B, Kolodzeiski E, Mönig H, Amirjalayer S, Fuchs H, Doltsinis NL, Glorius F. The Electron-Rich and Nucleophilic N-Heterocyclic Imines on Metal Surfaces: Binding Modes and Interfacial Charge Transfer. J Am Chem Soc 2024; 146:7288-7294. [PMID: 38456796 DOI: 10.1021/jacs.3c11738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/09/2024]
Abstract
The strongly electron-donating N-heterocyclic imines (NHIs) have been employed as excellent surface anchors for the thermodynamic stabilization of electron-deficient species due to their enhanced nucleophilicity. However, the binding mode and interfacial property of these new ligands are still unclear, representing a bottleneck for advanced applications in surface functionalization and catalysis. Here, NHIs with different side groups have been rationally designed, synthesized, and analyzed on various metal surfaces (Cu, Ag). Our results reveal different binding modes depending on the molecular structure and metal surface. The molecular design enables us to achieve a flat-lying or upright configuration and even a transition between these two binding modes depending on the coverage and time. Importantly, the two binding modes exhibit different degrees of interfacial charge transfer between the molecule and the surface. This study provides essential microscopic insight into the NHI adsorption geometry and interfacial charge transfer for the optimization of heterogeneous catalysts in coordination chemistry.
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Affiliation(s)
- Jindong Ren
- CAS Key Laboratory of Nanophotonic Materials and Devices, CAS Key Laboratory of Standardization and Measurement for Nanotechnology, National Center for Nanoscience and Technology, Beijing 100190, P.R. China
- University of Chinese Academy of Sciences, Beijing 100190, P.R. China
| | - Mowpriya Das
- Organisch-Chemisches Institut, Universität Münster, Corrensstraße 40, 48149 Münster, Germany
| | - Helena Osthues
- Institute for Solid State Theory and Center for Multiscale Theory and Computation, Universität Münster, Wilhelm-Klemm-Straße 10, 48149 Münster, Germany
| | - Marvin Nyenhuis
- Institute for Solid State Theory and Center for Multiscale Theory and Computation, Universität Münster, Wilhelm-Klemm-Straße 10, 48149 Münster, Germany
| | - Bertram Schulze Lammers
- Physikalisches Institut, Universität Münster, Wilhelm-Klemm-Straße 10, 48149 Münster, Germany
- Center for Nanotechnology, Heisenbergstraße 11, 48149 Münster, Germany
| | - Elena Kolodzeiski
- Physikalisches Institut, Universität Münster, Wilhelm-Klemm-Straße 10, 48149 Münster, Germany
- Center for Nanotechnology, Heisenbergstraße 11, 48149 Münster, Germany
| | - Harry Mönig
- Physikalisches Institut, Universität Münster, Wilhelm-Klemm-Straße 10, 48149 Münster, Germany
- Center for Nanotechnology, Heisenbergstraße 11, 48149 Münster, Germany
| | - Saeed Amirjalayer
- Institute for Solid State Theory and Center for Multiscale Theory and Computation, Universität Münster, Wilhelm-Klemm-Straße 10, 48149 Münster, Germany
| | - Harald Fuchs
- Physikalisches Institut, Universität Münster, Wilhelm-Klemm-Straße 10, 48149 Münster, Germany
- Center for Nanotechnology, Heisenbergstraße 11, 48149 Münster, Germany
| | - Nikos L Doltsinis
- Institute for Solid State Theory and Center for Multiscale Theory and Computation, Universität Münster, Wilhelm-Klemm-Straße 10, 48149 Münster, Germany
| | - Frank Glorius
- Organisch-Chemisches Institut, Universität Münster, Corrensstraße 40, 48149 Münster, Germany
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5
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Lee DS, Singh I, Veinot AJ, Aloisio MD, Lomax JT, Ragogna PJ, Crudden CM. Mesoionic carbene-based self-assembled monolayers on gold. Chem Sci 2024; 15:2480-2485. [PMID: 38362421 PMCID: PMC10866350 DOI: 10.1039/d3sc04720b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Accepted: 12/10/2023] [Indexed: 02/17/2024] Open
Abstract
N-Heterocyclic carbenes (NHC) have been widely studied as ligands for surface chemistry, and have shown advantages compared to existing ligands (e.g. thiols). Herein, we introduce mesoionic carbenes (MICs) as a new type of surface ligand. MICs exhibit higher σ-donor ability compared to typical NHCs, yet they have received little attention in the area of surface chemistry. The synthesis of MICs derived from imidazo[1,2-a]pyridine was established and fully characterized by spectroscopic methods. The self-assembly of these MICs on gold was analyzed by X-ray photoelectron spectroscopy (XPS). Additionally, XPS was used to compare bonding ability in MICs compared to the typical NHCs. These results show that MIC overlayers on gold are robust, resistant to replacement by NHCs, and may be superior to NHCs for applications that require even greater levels of robustness.
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Affiliation(s)
- Dianne S Lee
- Department of Chemistry, Queen's University 90 Bader Lane Kingston Ontario K7L 3N6 Canada
- Carbon to Metal Coating Institute, C2MCI, Queen's University 90 Bader Lane Kingston Ontario K7L 4V1 Canada
| | - Ishwar Singh
- Department of Chemistry, Queen's University 90 Bader Lane Kingston Ontario K7L 3N6 Canada
- Carbon to Metal Coating Institute, C2MCI, Queen's University 90 Bader Lane Kingston Ontario K7L 4V1 Canada
| | - Alex J Veinot
- Carbon to Metal Coating Institute, C2MCI, Queen's University 90 Bader Lane Kingston Ontario K7L 4V1 Canada
- Department of Chemistry, Western University London Ontario N6A 3K7 Canada
- Surface Science Western 999 Collip Cir London Ontario N6G 0J3 Canada
| | - Mark D Aloisio
- Department of Chemistry, Queen's University 90 Bader Lane Kingston Ontario K7L 3N6 Canada
- Carbon to Metal Coating Institute, C2MCI, Queen's University 90 Bader Lane Kingston Ontario K7L 4V1 Canada
| | - Justin T Lomax
- Carbon to Metal Coating Institute, C2MCI, Queen's University 90 Bader Lane Kingston Ontario K7L 4V1 Canada
- Department of Chemistry, Western University London Ontario N6A 3K7 Canada
- Surface Science Western 999 Collip Cir London Ontario N6G 0J3 Canada
| | - Paul J Ragogna
- Carbon to Metal Coating Institute, C2MCI, Queen's University 90 Bader Lane Kingston Ontario K7L 4V1 Canada
- Department of Chemistry, Western University London Ontario N6A 3K7 Canada
| | - Cathleen M Crudden
- Department of Chemistry, Queen's University 90 Bader Lane Kingston Ontario K7L 3N6 Canada
- Carbon to Metal Coating Institute, C2MCI, Queen's University 90 Bader Lane Kingston Ontario K7L 4V1 Canada
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6
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Zhang T, Khomane SB, Singh I, Crudden CM, McBreen PH. N-heterocyclic carbene adsorption states on Pt(111) and Ru(0001). Phys Chem Chem Phys 2024; 26:4083-4090. [PMID: 38226886 DOI: 10.1039/d3cp03539e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2024]
Abstract
N-heterocyclic carbene ligands (NHCs) are increasingly used to tune the properties of metal surfaces. The generally greater chemical and thermal robustness of NHCs on gold, as compared to thiolate surface ligands, underscores their potential for a range of applications. While much is now known about the adsorption geometry, overlayer structure, dynamics, and stability of NHCs on coinage elements, especially gold and copper, much less is known about their interaction with the surfaces of Pt-group metals, despite the importance of such metals in catalysis and electrochemistry. In this study, reflection absorption infrared spectroscopy (RAIRS) is used to probe the structure of benzimidazolylidene NHC ligands on Pt(111) and Ru(0001). The experiments exploit the intense absorption peaks of a CF3 substituent on the phenyl ring of the NHC backbone to provide unprecedented insight into adsorption geometry and chemical stability. The results also permit comparison with literature data for NHC ligands on Au(111) and to DFT predictions for NHCs on Pt(111) and Ru(0001), thereby greatly extending the known surface chemistry of NHCs and providing much needed molecular information for the design of metal-organic hybrid materials involving strongly reactive metals.
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Affiliation(s)
- Tianchi Zhang
- Département de chimie et CCVC, Université Laval, Québec (Que), Canada, G1K OA6.
| | - Sonali B Khomane
- Département de chimie et CCVC, Université Laval, Québec (Que), Canada, G1K OA6.
| | - Ishwar Singh
- Department of Chemistry, Queen's University, 90 Bader Lane, Kingston, Ontario, Canada, K7L 3N6.
| | - Cathleen M Crudden
- Department of Chemistry, Queen's University, 90 Bader Lane, Kingston, Ontario, Canada, K7L 3N6.
| | - Peter H McBreen
- Département de chimie et CCVC, Université Laval, Québec (Que), Canada, G1K OA6.
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7
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Das M, Hogan C, Zielinski R, Kubicki M, Koy M, Kosbab C, Brozzesi S, Das A, Nehring MT, Balfanz V, Brühne J, Dähne M, Franz M, Esser N, Glorius F. N-Heterocyclic Olefins on a Silicon Surface. Angew Chem Int Ed Engl 2023; 62:e202314663. [PMID: 37849449 DOI: 10.1002/anie.202314663] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Revised: 10/13/2023] [Accepted: 10/17/2023] [Indexed: 10/19/2023]
Abstract
The adsorption of N-heterocyclic olefins (NHOs) on silicon is investigated in a combined scanning tunneling microscopy, X-ray photoelectron spectroscopy, and density functional theory study. We find that both of the studied NHOs bind covalently, with ylidic character, to the silicon adatoms of the substrate and exhibit good thermal stability. The adsorption geometry strongly depends on the N-substituents: for large N-substituents, an upright adsorption geometry is favored, while a flat-lying geometry is found for the NHO with smaller wingtips. These different geometries strongly influence the quality and properties of the obtained monolayers. The upright geometry leads to the formation of ordered monolayers, whereas the flat-lying NHOs yield a mostly disordered, but denser, monolayer. The obtained monolayers both show large work function reductions, as the higher density of the flat-lying monolayer is found to compensate for the smaller vertical dipole moments. Our findings offer new prospects in the design of tailor-made ligand structures in organic electronics and optoelectronics, catalysis, and material science.
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Affiliation(s)
- Mowpriya Das
- Westfälische Wilhelms-Universität Münster, Organisch-Chemisches Institut, Corrensstrasse 40, 48149, Münster, Germany
| | - Conor Hogan
- Istituto di Struttura della Materia-CNR (ISM-CNR), Via del Fosso del Cavaliere 100, 00133, Rome, Italy
- Dipartimento di Fisica, Università di Roma 'Tor Vergata', Via della Ricerca Scientifica 1, 00133, Rome, Italy
| | - Robert Zielinski
- Technische Universität Berlin, Institut für Festkörperphysik, Hardenbergstrasse 36, D-10623, Berlin, Germany
| | - Milan Kubicki
- Technische Universität Berlin, Institut für Festkörperphysik, Hardenbergstrasse 36, D-10623, Berlin, Germany
| | - Maximilian Koy
- Westfälische Wilhelms-Universität Münster, Organisch-Chemisches Institut, Corrensstrasse 40, 48149, Münster, Germany
| | - Canan Kosbab
- Technische Universität Berlin, Institut für Festkörperphysik, Hardenbergstrasse 36, D-10623, Berlin, Germany
| | - Simone Brozzesi
- Dipartimento di Fisica, Università di Roma 'Tor Vergata', Via della Ricerca Scientifica 1, 00133, Rome, Italy
| | - Ankita Das
- Westfälische Wilhelms-Universität Münster, Organisch-Chemisches Institut, Corrensstrasse 40, 48149, Münster, Germany
| | - Mike Thomas Nehring
- Technische Universität Berlin, Institut für Festkörperphysik, Hardenbergstrasse 36, D-10623, Berlin, Germany
| | - Viktoria Balfanz
- Technische Universität Berlin, Institut für Festkörperphysik, Hardenbergstrasse 36, D-10623, Berlin, Germany
| | - Juls Brühne
- Technische Universität Berlin, Institut für Festkörperphysik, Hardenbergstrasse 36, D-10623, Berlin, Germany
| | - Mario Dähne
- Technische Universität Berlin, Institut für Festkörperphysik, Hardenbergstrasse 36, D-10623, Berlin, Germany
| | - Martin Franz
- Technische Universität Berlin, Institut für Festkörperphysik, Hardenbergstrasse 36, D-10623, Berlin, Germany
| | - Norbert Esser
- Technische Universität Berlin, Institut für Festkörperphysik, Hardenbergstrasse 36, D-10623, Berlin, Germany
- Leibniz-Institut für Analytische Wissenschaften - ISAS e.V., Schwarzschildstrasse 8, 12489, Berlin, Germany
| | - Frank Glorius
- Westfälische Wilhelms-Universität Münster, Organisch-Chemisches Institut, Corrensstrasse 40, 48149, Münster, Germany
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8
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Pellitero M, Jensen IM, Dominique NL, Ekowo LC, Camden JP, Jenkins DM, Arroyo-Currás N. Stability of N-Heterocyclic Carbene Monolayers under Continuous Voltammetric Interrogation. ACS APPLIED MATERIALS & INTERFACES 2023; 15:35701-35709. [PMID: 37449918 PMCID: PMC10377464 DOI: 10.1021/acsami.3c06148] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Accepted: 06/28/2023] [Indexed: 07/18/2023]
Abstract
N-Heterocyclic carbenes (NHCs) are promising monolayer-forming ligands that can overcome limitations of thiol-based monolayers in terms of stability, surface functionality, and reactivity across a variety of transition-metal surfaces. Recent publications have reported the ability of NHCs to support biomolecular receptors on gold substrates for sensing applications and improved tolerance to prolonged biofluid exposure relative to thiols. However, important questions remain regarding the stability of these monolayers when subjected to voltage perturbations, which is needed for applications with electrochemical platforms. Here, we investigate the ability of two NHCs, 1,3-diisopropylbenzimidazole and 5-(ethoxycarbonyl)-1,3-diisopropylbenzimidazole, to form monolayers via self-assembly from methanolic solutions of their trifluoromethanesulfonate salts. We compare the electrochemical behavior of the resulting monolayers relative to that of benchmark mercaptohexanol monolayers in phosphate-buffered saline. Within the -0.15 to 0.25 V vs Ag|AgCl voltage window, NHC monolayers are stable on gold surfaces, wherein they electrochemically perform like thiol-based monolayers and undergo similar reorganization kinetics, displaying long-term stability under incubation in buffered media and under continuous voltammetric interrogation. At negative voltages, NHC monolayers cathodically desorb from the electrode surface at lower bias (-0.1 V) than thiol-based monolayers (-0.5 V). At voltages more positive than 0.25 V, NHC monolayers anodically desorb from electrode surfaces at similar voltages to thiol-based monolayers. These results highlight new limitations to NHC monolayer stability imposed by electrochemical interrogation of the underlying gold electrodes. Our results serve as a framework for future optimization of NHC monolayers on gold for electrochemical applications, as well as structure-functionality studies of NHCs on gold.
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Affiliation(s)
- Miguel
Aller Pellitero
- Department
of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States
| | - Isabel M. Jensen
- Department
of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Nathaniel L. Dominique
- Department
of Chemistry and Biochemistry, University
of Notre Dame, Notre
Dame, Indiana 46556, United States
| | - Lilian Chinenye Ekowo
- Department
of Chemistry and Biochemistry, University
of Notre Dame, Notre
Dame, Indiana 46556, United States
| | - Jon P. Camden
- Department
of Chemistry and Biochemistry, University
of Notre Dame, Notre
Dame, Indiana 46556, United States
| | - David M. Jenkins
- Department
of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Netzahualcóyotl Arroyo-Currás
- Department
of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States
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9
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Dominique NL, Jensen IM, Kaur G, Kotseos CQ, Boggess WC, Jenkins DM, Camden JP. Giving Gold Wings: Ultrabright and Fragmentation Free Mass Spectrometry Reporters for Barcoding, Bioconjugation Monitoring, and Data Storage. Angew Chem Int Ed Engl 2023; 62:e202219182. [PMID: 36853583 DOI: 10.1002/anie.202219182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Revised: 02/24/2023] [Accepted: 02/27/2023] [Indexed: 03/01/2023]
Abstract
The widespread application of laser desorption/ionization mass spectrometry (LDI-MS) highlights the need for a bright and multiplexable labeling platform. While ligand-capped Au nanoparticles (AuNPs) have emerged as a promising LDI-MS contrast agent, the predominant thiol ligands suffer from low ion yields and extensive fragmentation. In this work, we develop a N-heterocyclic carbene (NHC) ligand platform that enhances AuNP LDI-MS performance. NHC scaffolds are tuned to generate barcoded AuNPs which, when benchmarked against thiol-AuNPs, are bright mass tags and form unfragmented ions in high yield. To illustrate the transformative potential of NHC ligands, the mass tags were employed in three orthogonal applications: monitoring a bioconjugation reaction, performing multiplexed imaging, and storing and reading encoded information. These results demonstrate that NHC-nanoparticle systems are an ideal platform for LDI-MS and greatly broaden the scope of nanoparticle contrast agents.
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Affiliation(s)
- Nathaniel L Dominique
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, 46556, USA
| | - Isabel M Jensen
- Department of Chemistry, University of Tennessee, Knoxville, Knoxville, TN, 37996, USA
| | - Gurkiran Kaur
- Department of Chemistry, University of Tennessee, Knoxville, Knoxville, TN, 37996, USA
| | - Chandler Q Kotseos
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, 46556, USA
| | - William C Boggess
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, 46556, USA
| | - David M Jenkins
- Department of Chemistry, University of Tennessee, Knoxville, Knoxville, TN, 37996, USA
| | - Jon P Camden
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, 46556, USA
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10
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Knecht P, Meier D, Reichert J, Duncan DA, Schwarz M, Küchle JT, Lee T, Deimel PS, Feulner P, Allegretti F, Auwärter W, Médard G, Seitsonen AP, Barth JV, Papageorgiou AC. N‐Heterocyclic Carbenes: Molecular Porters of Surface Mounted Ru‐Porphyrins. Angew Chem Int Ed Engl 2022; 61:e202211877. [PMID: 36200438 PMCID: PMC10092334 DOI: 10.1002/anie.202211877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Indexed: 11/30/2022]
Abstract
Ru-porphyrins act as convenient pedestals for the assembly of N-heterocyclic carbenes (NHCs) on solid surfaces. Upon deposition of a simple NHC ligand on a close packed Ru-porphyrin monolayer, an extraordinary phenomenon can be observed: Ru-porphyrin molecules are transferred from the silver surface to the next molecular layer. We have investigated the structural features and dynamics of this portering process and analysed the associated binding strengths and work function changes. A rearrangement of the molecular layer is induced by the NHC uptake: the NHC selective binding to the Ru causes the ejection of whole porphyrin molecules from the molecular layer on silver to the layer on top. This reorganisation can be reversed by thermally induced desorption of the NHC ligand. We anticipate that the understanding of such mass transport processes will have crucial implications for the functionalisation of surfaces with carbenes.
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Affiliation(s)
- Peter Knecht
- Physics Department E20 Technical University of Munich James Franck Straße 1 85748 Garching Germany
| | - Dennis Meier
- Physics Department E20 Technical University of Munich James Franck Straße 1 85748 Garching Germany
| | - Joachim Reichert
- Physics Department E20 Technical University of Munich James Franck Straße 1 85748 Garching Germany
| | - David A. Duncan
- Diamond Light Source Harwell Science and Innovation Campus Didcot OX11 0QX UK
| | - Martin Schwarz
- Physics Department E20 Technical University of Munich James Franck Straße 1 85748 Garching Germany
| | - Johannes T. Küchle
- Physics Department E20 Technical University of Munich James Franck Straße 1 85748 Garching Germany
| | - Tien‐Lin Lee
- Diamond Light Source Harwell Science and Innovation Campus Didcot OX11 0QX UK
| | - Peter S. Deimel
- Physics Department E20 Technical University of Munich James Franck Straße 1 85748 Garching Germany
| | - Peter Feulner
- Physics Department E20 Technical University of Munich James Franck Straße 1 85748 Garching Germany
| | - Francesco Allegretti
- Physics Department E20 Technical University of Munich James Franck Straße 1 85748 Garching Germany
| | - Willi Auwärter
- Physics Department E20 Technical University of Munich James Franck Straße 1 85748 Garching Germany
| | - Guillaume Médard
- Chair of Proteomics and Bioanalytics Technical University of Munich Emil Erlenmeyer Forum 5 85354 Freising Germany
| | - Ari Paavo Seitsonen
- Département de Chimie École Normale Supérieure 24 rue Lhomond 75005 Paris France
- Université de recherche Paris-Sciences-et-Lettres Sorbonne Université Centre National de la Recherche Scientifique 75005 Paris France
| | - Johannes V. Barth
- Physics Department E20 Technical University of Munich James Franck Straße 1 85748 Garching Germany
| | - Anthoula C. Papageorgiou
- Physics Department E20 Technical University of Munich James Franck Straße 1 85748 Garching Germany
- Department of Chemistry Laboratory of Physical Chemistry National and Kapodistrian University of Athens Panepistimiopolis 157 71 Athens Greece
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