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Peters EH, Mayor M. Alkyne‐Monofunctionalized Gold Nanoparticles as Massive Molecular Building Blocks. Eur J Inorg Chem 2020. [DOI: 10.1002/ejic.202000273] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Erich Henrik Peters
- Departement of Chemistry University of Basel St. Johanns‐Ring 19 4056 Basel Switzerland
| | - Marcel Mayor
- Departement of Chemistry University of Basel St. Johanns‐Ring 19 4056 Basel Switzerland
- Institute for Nanotechnology (INT) Karlsruhe Institute of Technology (KIT) P. O. Box 3640 76021 Karlsruhe Germany
- Lehn Institute of Functional Materials (LIFM) Sun Yat‐Sen University (SYSU) Xingang Xi Rd. 135 510275 Guangzhou P. R. China
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Kitagawa T, Kawano T, Hase T, Hayakawa I, Hirai K, Okazaki T. Electron-Transfer Properties of Phenyleneethynylene Linkers Bound to Gold via a Self-Assembled Monolayer of Molecular Tripod. Molecules 2018; 23:molecules23112893. [PMID: 30404166 PMCID: PMC6278298 DOI: 10.3390/molecules23112893] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2018] [Revised: 10/20/2018] [Accepted: 10/30/2018] [Indexed: 11/16/2022] Open
Abstract
The three-point adsorption of tripod-shaped molecules enables the formation of robust self-assembled monolayers (SAMs) on solid surfaces, where the component molecules are fixed in a strictly upright orientation. In the present study, SAMs of a rigid molecular tripod consisting of an adamantane core and three CH₂SH groups were employed to arrange ferrocene on a gold surface through oligo(p-phenyleneethynylene) linkers. Cyclic voltammetry of the monolayers demonstrated high surface coverage of ferrocene, yet the molecular interaction among adjacent ferrocene units was negligible. This was because of the extended intermolecular distance caused by the bulky tripod framework. The rates of electron transfer from the ferrocene to the gold surface through different linker lengths were determined by electrochemical measurements, from which the decay factor for oligo(p-phenyleneethynylene) wire was evaluated.
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Affiliation(s)
- Toshikazu Kitagawa
- Department of Chemistry for Materials, Graduate School of Engineering, Mie University, Tsu, Mie 514-8507, Japan.
| | - Takashi Kawano
- Department of Chemistry for Materials, Graduate School of Engineering, Mie University, Tsu, Mie 514-8507, Japan.
| | - Takahiro Hase
- Department of Chemistry for Materials, Graduate School of Engineering, Mie University, Tsu, Mie 514-8507, Japan.
| | - Ikuma Hayakawa
- Department of Chemistry for Materials, Graduate School of Engineering, Mie University, Tsu, Mie 514-8507, Japan.
| | - Katsuyuki Hirai
- Organization for the Promotion of Regional Innovation, Mie University, Tsu, Mie 514-8507, Japan.
| | - Takao Okazaki
- Department of Chemistry for Materials, Graduate School of Engineering, Mie University, Tsu, Mie 514-8507, Japan.
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Investigation of the geometrical arrangement and single molecule charge transport in self-assembled monolayers of molecular towers based on tetraphenylmethane tripod. Electrochim Acta 2017. [DOI: 10.1016/j.electacta.2017.11.174] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Valášek M, Mayor M. Spatial and Lateral Control of Functionality by Rigid Molecular Platforms. Chemistry 2017; 23:13538-13548. [PMID: 28766790 DOI: 10.1002/chem.201703349] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Indexed: 11/11/2022]
Abstract
Surface mounted molecular devices have received significant attention in the scientific community because of their unique ability to construct functional materials. The key involves the platform on which the molecular device works on solid substrates, such as in solid-liquid or solid-vacuum interfaces. Here, we outline the concept of rigid molecular platforms to immobilize active functionality atop flat surfaces in a controllable manner. Most of these (multipodal) platforms have at least three anchoring groups to control the spatial arrangement of the protruding functional moieties and form mechanically stable and electronically tuned contacts to the underlying substrate. Another approach is based on employing of flat aromatic scaffolds bearing perpendicular functionalities that form stable lateral assemblies on various surfaces. Emphasis is placed on the need for controllable assembly and separation of these tailor-made molecules that expose functionalities at the molecular scale. The discussions are focused on the different molecular designs realizing functional 3D architectures on surfaces, the role of various anchoring strategies to control the spatial arrangement, and structural considerations controlling physical features like the coupling to the surface or the available space for sterically demanding molecular operations.
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Affiliation(s)
- Michal Valášek
- Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany
| | - Marcel Mayor
- Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany.,Lehn Institute of Functional Materials (LIFM), Sun Yat-Sen University (SYSU), Xingang Rd. W., Guangzhou, P. R. China.,Department of Chemistry, University of Basel, St. Johannsring 19, 4056, Basel, Switzerland
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Sahu P, Shimpi J, Lee HJ, Lee TR, Prasad BLV. Digestive Ripening of Au Nanoparticles Using Multidentate Ligands. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:1943-1950. [PMID: 28127959 DOI: 10.1021/acs.langmuir.6b03998] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The efficiency of multidentate ligands as digestive ripening (DR) agents for the preparation of monodisperse Au nanoparticles (NPs) was investigated. This systematic investigation was performed using ligands possessing one, two, or three thiol moieties as ligands/DR agents. Our results clearly establish that among the different ligands, monodentate ligands and the use of temperature in the range of 60-120 °C offer the best conditions for DR. In addition, when DR was carried out at lower temperatures (e.g., 60 °C), the NP size increased as the number of thiol groups per ligand increased. However, in the case of ligands possessing two and three thiol moieties, when they were heated with polydispersed particles at higher temperatures (120 or 180 °C), the etching process dominated, which affected the quality of the NPs in terms of their monodispersity. We conclude that the temperature-dependent strength of the interaction between the ligand headgroup and the NP surface plays a vital role in controlling the final particle sizes.
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Affiliation(s)
- Puspanjali Sahu
- Materials Chemistry Division, National Chemical Laboratory , Dr. Homi Bhabha Road, Pune 411008, India
| | - Jayesh Shimpi
- Materials Chemistry Division, National Chemical Laboratory , Dr. Homi Bhabha Road, Pune 411008, India
| | - Han Ju Lee
- Department of Chemistry, University of Houston , Houston, Texas 77204-5003, United States
| | - T Randall Lee
- Department of Chemistry, University of Houston , Houston, Texas 77204-5003, United States
| | - Bhagavatula L V Prasad
- Materials Chemistry Division, National Chemical Laboratory , Dr. Homi Bhabha Road, Pune 411008, India
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Valášek M, Lindner M, Mayor M. Rigid multipodal platforms for metal surfaces. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2016; 7:374-405. [PMID: 27335731 PMCID: PMC4901557 DOI: 10.3762/bjnano.7.34] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2015] [Accepted: 02/17/2016] [Indexed: 06/05/2023]
Abstract
In this review the recent progress in molecular platforms that form rigid and well-defined contact to a metal surface are discussed. Most of the presented examples have at least three anchoring units in order to control the spatial arrangement of the protruding molecular subunit. Another interesting feature is the lateral orientation of these foot structures which, depending on the particular application, is equally important as the spatial arrangement of the molecules. The numerous approaches towards assembling and organizing functional molecules into specific architectures on metal substrates are reviewed here. Particular attention is paid to variations of both, the core structures and the anchoring groups. Furthermore, the analytical methods enabling the investigation of individual molecules as well as monomolecular layers of ordered platform structures are summarized. The presented multipodal platforms bearing several anchoring groups form considerably more stable molecule-metal contacts than corresponding monopodal analogues and exhibit an enlarged separation of the functional molecules due to the increased footprint, as well as restrict tilting of the functional termini with respect to the metal surface. These platforms are thus ideally suited to tune important properties of the molecule-metal interface. On a single-molecule level, several of these platforms enable the control over the arrangement of the protruding rod-type molecular structures (e.g., molecular wires, switches, rotors, sensors) with respect to the surface of the substrate.
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Affiliation(s)
- Michal Valášek
- Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen, Germany
| | - Marcin Lindner
- Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen, Germany
| | - Marcel Mayor
- Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen, Germany
- Lehn Institute of Functional Materials (LIFM), Sun Yat-Sen University (SYSU), Xingang Rd. W., Guangzhou, China
- Department of Chemistry, University of Basel, St. Johannsring 19, CH-4056 Basel, Switzerland
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Mezour MA, Perepichka II, Ivasenko O, Lennox RB, Perepichka DF. Tridentate benzylthiols on Au(111): control of self-assembly geometry. NANOSCALE 2015; 7:5014-5022. [PMID: 25695677 DOI: 10.1039/c4nr07207c] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
A set of hexasubstituted benzene derivatives with three thiol groups in the 1, 3, 5 positions and varied aliphatic substituents in the 2, 4, 6 positions (Me3-BTMT, Et3-BTMT, ODe3-BTMT) has been synthesized and self-assembled on Au(111). The resulting self-assembled monolayers (SAMs) are characterized by scanning tunneling microscopy (STM), X-ray photoelectron spectroscopy (XPS), and electrochemistry. The molecular orientation and long-range order are affected by the “gear effect” of the hexasubstituted benzene ring and van der Waals interactions between the physisorbed alkyl chains drive. Me3-BTMT adopts a standing up orientation which results in the highest molecular surface density but also the lowest degree of chemisorption (1 to 2 Au–S bonds per molecule). In contrast, Et3-BTMT favors a lying down orientation with a greater number of surface-bonded thiol groups (2 to 3) per molecule, associated with the peculiar geometry of this molecule. Finally, ODe3-BTMT adsorbs mainly in a lying down orientation, forming the SAM with the highest degree of chemisorption (all thiol groups are gold-bonded) and the lowest molecular areal density.
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Affiliation(s)
- Mohamed A Mezour
- Department of Chemistry and Centre for Self-Assembled Chemical Structures, McGill University, 801 Sherbrooke St. West, Montreal (QC) H3A 0B8, Canada.
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Kitagawa T, Matsubara H, Okazaki T, Komatsu K. Electrochemistry of the self-assembled monolayers of dyads consisting of tripod-shaped trithiol and bithiophene on gold. Molecules 2014; 19:15298-313. [PMID: 25255246 PMCID: PMC6271350 DOI: 10.3390/molecules190915298] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2014] [Revised: 09/02/2014] [Accepted: 09/17/2014] [Indexed: 11/16/2022] Open
Abstract
Self-assembled monolayers (SAMs) of tripod-shaped trithiols, consisting of an adamantane core with three CH2SH legs and a bithiophene group, were prepared on a Au(111) surface. Adsorption in a tripod-like fashion was supported by polarization modulation-infrared reflection absorption spectroscopy (PM-IRRAS) of the SAMs, which indicated the absence of free SH groups. Cyclic voltammetry showed an irreversible cathodic wave due to reductive desorption. The SAM also showed an anodic wave due to the single-electron oxidation of the bithiophene moiety without concomitant desorption of the molecules. Although oxidation was irreversible in the absence of a protecting group, it became reversible with the introduction of a terminal phenyl group. The charge of the oxidation was one-third that of the reductive desorption, confirming a three-point adsorption. The surface coverage was ca. 50% of that expected for the anti bithiophene conformation, which suggested that an increase in the surface area per molecule had been caused by the presence of an energetically high-lying syn conformer. In accordance with this, the line shape of the oxidation wave suggested an electrostatic repulsive interaction between neighboring molecules.
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Affiliation(s)
- Toshikazu Kitagawa
- Department of Chemistry for Materials, Graduate School of Engineering, Mie University, Tsu, Mie 514-8507, Japan.
| | - Hiroaki Matsubara
- Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan
| | - Takao Okazaki
- Department of Chemistry for Materials, Graduate School of Engineering, Mie University, Tsu, Mie 514-8507, Japan
| | - Koichi Komatsu
- Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan
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Totaro P, Poggini L, Favre A, Mannini M, Sainctavit P, Cornia A, Magnani A, Sessoli R. Tetrairon(III) single-molecule magnet monolayers on gold: insights from ToF-SIMS and isotopic labeling. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:8645-8649. [PMID: 25000391 DOI: 10.1021/la500846a] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
To work as magnetic components in molecular electronics and spintronics, single-molecule magnets (SMMs) must be reliably interfaced with metals. The organization on gold of a Fe4 SMM carrying two acetyl-protected thiol groups has been studied by exploiting the surface sensitivity of time-of-flight secondary ion mass spectrometry (ToF-SIMS), additionally powered by the use of an isotopic labeling strategy. Deposition from millimolar dichloromethane solutions results in a higher surface coverage and better packed monolayers as compared with previous protocols based on more diluted solutions. Fe4 complexes are chemically tethered to the surface via a single Au-S bond while they still contain an intact SAc group.
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Affiliation(s)
- Pasquale Totaro
- Laboratory of Molecular Magnetism (LaMM), Dipartimento di Chimica "Ugo Schiff", Università degli Studi di Firenze & INSTM RU of Firenze , via della Lastruccia 3-13, 50019 Sesto Fiorentino, Florence, Italy
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Valášek M, Edelmann K, Gerhard L, Fuhr O, Lukas M, Mayor M. Synthesis of Molecular Tripods Based on a Rigid 9,9′-Spirobifluorene Scaffold. J Org Chem 2014; 79:7342-57. [DOI: 10.1021/jo501029t] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Affiliation(s)
- Michal Valášek
- Institute
of Nanotechnology, Karlsruhe Institute of Technology (KIT), P.O. Box 3640, D-76021 Karlsruhe, Germany
- DFG
Center for Functional Nanostructures (CFN), Karlsruhe Institute of Technology (KIT), Wolfgang-Gaede-Str. 1a, D-76131 Karlsruhe, Germany
| | - Kevin Edelmann
- Institute
of Nanotechnology, Karlsruhe Institute of Technology (KIT), P.O. Box 3640, D-76021 Karlsruhe, Germany
| | - Lukas Gerhard
- Institute
of Nanotechnology, Karlsruhe Institute of Technology (KIT), P.O. Box 3640, D-76021 Karlsruhe, Germany
| | - Olaf Fuhr
- Institute
of Nanotechnology, Karlsruhe Institute of Technology (KIT), P.O. Box 3640, D-76021 Karlsruhe, Germany
| | - Maya Lukas
- Institute
of Nanotechnology, Karlsruhe Institute of Technology (KIT), P.O. Box 3640, D-76021 Karlsruhe, Germany
| | - Marcel Mayor
- Institute
of Nanotechnology, Karlsruhe Institute of Technology (KIT), P.O. Box 3640, D-76021 Karlsruhe, Germany
- DFG
Center for Functional Nanostructures (CFN), Karlsruhe Institute of Technology (KIT), Wolfgang-Gaede-Str. 1a, D-76131 Karlsruhe, Germany
- Department
of Chemistry, University of Basel, St. Johannsring 19, CH-4056 Basel, Switzerland
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Kitagawa T, Matsubara H, Komatsu K, Hirai K, Okazaki T, Hase T. Ideal redox behavior of the high-density self-assembled monolayer of a molecular tripod on a Au(111) surface with a terminal ferrocene group. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:4275-4282. [PMID: 23470152 DOI: 10.1021/la305092g] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
A dyad consisting of a tripod-shaped trithiol with an adamantane core and a terminal ferrocenyl group linked through ap-phenyleneethynylene bridge was synthesized. The trithiol formed a stable self-assembled monolayer (SAM) on Au(111), wherein each molecule is bound to the surface by three-point adsorption using all sulfur atoms, with confirmation by PM-IRRAS and XPS analyses. Cyclic voltammetry of the SAM showed a line shape typical of an ideal adsorbed system, that is, a monolayer with negligible electrostatic interaction among the terminal ferrocenyl groups. Thus, a rare SAM was achieved, in which the component molecules were isolated from adjacent molecules without the coadsorption of nonelectroactive molecules.
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Affiliation(s)
- Toshikazu Kitagawa
- Department of Chemistry for Materials, Graduate School of Engineering, Mie University, Tsu, Mie, Japan.
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Sakamoto R, Ohirabaru Y, Matsuoka R, Maeda H, Katagiri S, Nishihara H. Orthogonal bis(terpyridine)–Fe(ii) metal complex oligomer wires on a tripodal scaffold: rapid electron transport. Chem Commun (Camb) 2013; 49:7108-10. [DOI: 10.1039/c3cc42478b] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Schramm A, Stroh C, Dössel K, Lukas M, Fischer M, Schramm F, Fuhr O, Löhneysen HV, Mayor M. Tripodal MIIIComplexes on Au(111) Surfaces: Towards Molecular “Lunar Modules”. Eur J Inorg Chem 2012. [DOI: 10.1002/ejic.201200928] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Weidner T, Baio JE, Seibel J, Siemeling U. Dithienylcyclopentene-functionalised subphthalocyaninatoboron complexes: photochromism, luminescence modulation and formation of self-assembled monolayers on gold. Dalton Trans 2012; 41:1553-61. [PMID: 22138955 DOI: 10.1039/c1dt11644d] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Subphthalocyaninatoboron (SubPc) complexes bearing six peripheral n-dodecylthio substituents and an apical photochromic dithienylperfluorocyclopentene unit were prepared. The photoinduced isomerisation of the apical substituent from the open to the ring-closed form significantly influences the photoluminescence of the covalently attached SubPc unit, which is more efficiently quenched by the ring-closed form. Films on gold were fabricated from these multifunctional conjugates and characterised by near-edge X-ray absorption fine structure (NEXAFS) and X-ray photoelectron spectroscopy (XPS). The results are in accord with the formation of self-assembled monolayers based on dome-shaped SubPc-based anchor groups. Their chemisorption is primarily due to the peripheral n-dodecylthio substituents, giving rise to covalently attached thiolate as well as coordinatively bound thioether units, whose alkyl chains are in an almost parallel orientation to the surface.
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Affiliation(s)
- Tobias Weidner
- National ESCA and Surface Analysis Center for Biomedical Problems (NESAC/BIO), Department of Bioengineering, University of Washington, Seattle, Washington 98195, USA
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Krawicz A, Palazzo J, Wang GC, Dinolfo PH. Layer-by-layer assembly of Zn(ii) and Ni(ii) 5,10,15,20-tetra(4-ethynylphenyl)porphyrin multilayers on Au using copper catalyzed azide-alkyne cycloaddition. RSC Adv 2012. [DOI: 10.1039/c2ra20440a] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
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Abstract
The inexorable drive to miniaturize information storage and processing devices has fueled the dreams of scientists pursuing molecular electronics: researchers in the field envisage exquisitely tailored molecular materials fulfilling the functions now carried out by semiconductors. A bottom-up assembly of such all-molecular devices would complement, if not supplant, the present top-down lithographic procedures of modern semiconductor fabrication. Short of these grand aspirations, a more near-term objective is to construct hybrid architectures wherein molecules are incorporated in semiconductor-based devices. Such a combined approach exploits the advantages of molecules for selected device functions while retaining the well-developed lithographic approaches for fabrication of the overall chip. In this Account, we survey more than a decade of results from our research programs to employ porphyrin molecules as charge-storage elements in hybrid semiconductor-molecular dynamic random access memory. Porphyrins are attractive for a variety of reasons: they meet the stability criteria for use in real-world applications, they are readily prepared and tailored synthetically, they undergo read-write processes at low potential, and they store charge for extended periods (up to minutes) in the absence of applied potential. Porphyrins typically exhibit two cationic redox states. Molecular architectures with greater than two cationic redox states are achieved by combinations of porphyrins in a variety of structures (for example, dyads, wherein the porphyrins have distinct potentials, triple deckers, and dyads of triple deckers). The incorporation of porphyrins in hybrid architectures has also required diverse tethers (alkyl, alkenyl, alkynyl, aryl, and combinations thereof) and attachment groups (alcohol, thiol, selenol, phosphonate, and hydrocarbon) for linkage to a variety of surfaces (Au, Si, SiO(2), TiN, Ge, and so forth). The porphyrins as monolayers exhibit high charge density and are robust to high-temperature excursions (400 °C for 30 min) under inert atmosphere conditions. Even higher charge densities, which are invaluable for device applications, were achieved by in situ formation of porphyrin polymers or by stepwise growth of porphyrin-imide oligomers. The various molecular architectures have been investigated by diverse surface characterization methods, including ellipsometry, atomic force microscopy, FTIR spectroscopy, and X-ray photoelectron spectroscopy, as well as a variety of electrochemical methods. These studies have further revealed that the porphyrin layers are robust under conditions of deposition of a top metal contact. The results to date indicate the superior features of selected molecular architectures for molecular electronics applications. The near-term utilization of such materials depends on further work for appropriate integration in semiconductor-based devices, whereas ultimate adoption may depend on advances that remain far afield, such as the development of fully bottom-up assembly processes.
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Affiliation(s)
- Jonathan S. Lindsey
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204, United States
| | - David F. Bocian
- Department of Chemistry, University of California, Riverside, California 92521-0403, United States
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Siemeling U, Schirrmacher C, Glebe U, Bruhn C, Baio JE, Árnadóttir L, Castner DG, Weidner T. Phthalocyaninato complexes with peripheral alkylthio chains: disk-like adsorbate species for the vertical anchoring of ligands on gold surfaces. Inorganica Chim Acta 2011; 374:302-312. [PMID: 21857743 PMCID: PMC3156452 DOI: 10.1016/j.ica.2011.02.048] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Thin metalorganic films were prepared on gold by self-assembly of thioether-functionalised phthalocyaninato complexes from solution. The phthalocyaninato ligands used contain eight peripheral, β-positioned, alkylthio substituents SR (1a: R = n-C(8)H(17), 1b: R = n-C(12)H(25)), which serve as headgroups for surface binding and promote lateral assembly, while the disk-like phthalocyaninato core offers the scope for the attachment of axial ligands to the adsorbed molecules. This process was mimicked by coordination of pyridine (Py) to [Zn(1a)] and [Zn(1b)], respectively. The crystal structures of the products [Zn(1a)(Py)] and [Zn(1b)(Py)] were determined. The crystal structures of 4,5-bis(octylthio)phthalodinitrile and 4,5-bis(dodecylthio)phthalodinitrile were also determined. The films fabricated from [Mn(1a)Cl] and [Mn(1b)Cl] on gold were characterised by XPS, ToF-SIMS and NEXAFS spectroscopy, which revealed the presence of well-defined and homogeneous self-assembled monolayers (SAMs), whose constituents are bound to the substrate by thioether-gold linkages. The orientation of the macrocycles is predominantly parallel to the surface. Strong electronic interaction of the manganese(III) centre with the substrate leads to Cl loss upon adsorption and its reduction to Mn(II).
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Affiliation(s)
- Ulrich Siemeling
- Institute of Chemistry, University of Kassel, 34109 Kassel, Germany
- Center for Interdisciplinary Nanostructure Science and Technology (CINSaT), University of Kassel, 34109 Kassel, Germany
| | - Christian Schirrmacher
- Institute of Chemistry, University of Kassel, 34109 Kassel, Germany
- Center for Interdisciplinary Nanostructure Science and Technology (CINSaT), University of Kassel, 34109 Kassel, Germany
| | - Ulrich Glebe
- Institute of Chemistry, University of Kassel, 34109 Kassel, Germany
- Center for Interdisciplinary Nanostructure Science and Technology (CINSaT), University of Kassel, 34109 Kassel, Germany
| | - Clemens Bruhn
- Institute of Chemistry, University of Kassel, 34109 Kassel, Germany
| | - Joe E. Baio
- National ESCA and Surface Analysis Center for Biomedical Problems (NESAC/BIO), Departments of Bioengineering and Chemical Engineering, University of Washington, Seattle, Washington 98195, USA
| | - Líney Árnadóttir
- National ESCA and Surface Analysis Center for Biomedical Problems (NESAC/BIO), Departments of Bioengineering and Chemical Engineering, University of Washington, Seattle, Washington 98195, USA
| | - David G. Castner
- National ESCA and Surface Analysis Center for Biomedical Problems (NESAC/BIO), Departments of Bioengineering and Chemical Engineering, University of Washington, Seattle, Washington 98195, USA
| | - Tobias Weidner
- National ESCA and Surface Analysis Center for Biomedical Problems (NESAC/BIO), Departments of Bioengineering and Chemical Engineering, University of Washington, Seattle, Washington 98195, USA
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Pietrangeli D, Ricciardi G. Synthesis of porphyrazines bearing thioalkylthiol tethers: useful building blocks for supramolecular chemistry. Tetrahedron Lett 2011. [DOI: 10.1016/j.tetlet.2010.12.103] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Ie Y, Hirose T, Nakamura H, Kiguchi M, Takagi N, Kawai M, Aso Y. Nature of Electron Transport by Pyridine-Based Tripodal Anchors: Potential for Robust and Conductive Single-Molecule Junctions with Gold Electrodes. J Am Chem Soc 2011; 133:3014-22. [DOI: 10.1021/ja109577f] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Yutaka Ie
- The Institute of Scientific
and Industrial Research (ISIR), Osaka University, 8-1, Mihogaoka, Ibaraki, Osaka 567-0047, Japan
- PRESTO-JST, 4-1-8, Honcho, Kawaguchi, Saitama 333-0012, Japan
| | - Tomoya Hirose
- The Institute of Scientific
and Industrial Research (ISIR), Osaka University, 8-1, Mihogaoka, Ibaraki, Osaka 567-0047, Japan
| | - Hisao Nakamura
- Nanosystem Research Institute (NRI)
“RICS”, National Institute of Advanced Industrial Science and Technology (AIST), Central 2,
Umezono 1-1-1, Tsukuba, Ibaraki 305-8568, Japan
| | - Manabu Kiguchi
- Department of Chemistry, Graduate
School of Science and Engineering, Tokyo Institute of Technology, 2-12-1 W4-10, Ookayama, Meguro-ku, Tokyo
152-8551, Japan
| | - Noriaki Takagi
- Department of Advanced Materials
Science, The University of Tokyo, Kashiwa,
Chiba 277-8561, Japan
| | - Maki Kawai
- Department of Advanced Materials
Science, The University of Tokyo, Kashiwa,
Chiba 277-8561, Japan
- Surface Chemistry Laboratory, RIKEN, Wako, Saitama 351-0198, Japan
| | - Yoshio Aso
- The Institute of Scientific
and Industrial Research (ISIR), Osaka University, 8-1, Mihogaoka, Ibaraki, Osaka 567-0047, Japan
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20
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Amatatsu Y. Theoretical study on the photochemical behavior of 4-dimethylamino-4'-cyanodiphenylacetylene. J Phys Chem A 2010; 114:543-51. [PMID: 19894701 DOI: 10.1021/jp907492r] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The photochemical behavior of 4-dimethylamino-4'-cyanodiphenylacetylene (DCDPA) has been examined by ab initio complete active space self-consistent field (CASSCF) and its second-order multireference Moller-Plesset perturbation (MRMP2) methods. DCDPA is mainly excited into an internal charge-transfer (ICT) state where the charge transfers from the dimethylanilino group into the benzonitrile part. In S(1), there are two stable geometries. One is an ICT state where DCDPA is skeletally relaxed from the stable geometry in S(0) upon electronic excitation. The other is a diradical state where DCDPA takes a trans-bent form and the acetylenic C identical withC triple bond turns to be an ethylenic C horizontal lineC double bond, as already confirmed in the case of parent diphenylacetylene. On the way to the globally stable trans-bent form in S(1), a conical intersection between the charge-transfer and the diradical state is located. The photochemical behavior of DCDPA in polar solvent has been also examined by CASSCF combined with the polarized continuum model. Thereby, it was found that a twisted ICT (TICT) state where the dimethylanilino group is perpendicularly twisted against the remaining part is formed in polar solvent.
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Affiliation(s)
- Yoshiaki Amatatsu
- Faculty of Engineering and Resource Science, Akita University, Tegata Gakuen-cho, Akita 010-8502, Japan.
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Matino F, Schull G, Jana U, Köhler F, Berndt R, Herges R. Single azopyridine-substituted porphyrin molecules for configurational and electronic switching. Chem Commun (Camb) 2010; 46:6780-2. [DOI: 10.1039/c0cc00959h] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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22
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Ha JM, Solovyov A, Katz A. Synthesis and characterization of accessible metal surfaces in calixarene-bound gold nanoparticles. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:10548-10553. [PMID: 19645476 DOI: 10.1021/la9013174] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Use of organic ligands to partially passivate nanoparticles against sintering yet retain a degree of small molecule accessibility to the metal surface has been a lofty goal in functional materials synthesis, which in principle also enables the design of preferred electronic and steric environments on a nanoparticle surface. Catalysis using gold in particular requires donor ligands that facilitate an electron-rich metal surface and generalizable strategies for dealing with deactivation due to sintering. Here, synthesis and characterization of gold nanoparticles postsynthetically modified with the chelating ligand cone-5,11,17,23,29,35-hexa(tert-butyl)-37,39,41-tris(diphenylphosphinomethoxy)-38,40,42-trimethoxycalix[6]arene (1) is reported. In solution as well as when supported on the surface of TiO2, nanoparticles modified with tripodal calix[6]arene phosphine ligand 1 demonstrate enhanced protection against sintering relative to unmodified, tetraoctylammonium bromide-surfactant-stabilized gold nanoparticles. In between adsorbed calixarene ligands, there is accessible gold surface area in these nanoparticles, and this is measured quantitatively for the first time for a calixarene-modified nanoparticle, using a newly developed fluorescence methodology involving 2-naphthalenethiol as a relevant chemisorption probe molecule. Ligand steric bulk critically influences amount of accessible surface on the metal nanoparticle since the use of a smaller calix[4]arene ligand (MBC) results in a 7-fold lower accessible surface area relative to using 1 under otherwise similar conditions. In addition, surface coverage of 1 controls accessible surface area in an unintuitive fashion: a 4-fold increase in accessible metal surface area is observed upon increasing the surface coverage of 1 to be 1.5-fold higher than the minimum required for surface saturation. This is presumably the result of a more open ligand packing of 1 at higher surface coverages, which allows greater accessibility to 2-napthalenethiol.
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Affiliation(s)
- Jeong-Myeong Ha
- Department of Chemical Engineering, University of California, Berkeley, California 94720-1462, USA
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23
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Baisch B, Raffa D, Jung U, Magnussen OM, Nicolas C, Lacour J, Kubitschke J, Herges R. Mounting freestanding molecular functions onto surfaces: the platform approach. J Am Chem Soc 2009; 131:442-3. [PMID: 19113847 DOI: 10.1021/ja807923f] [Citation(s) in RCA: 144] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A modular system has been developed to mount molecules upright onto metal surfaces in a well controlled geometry. The approach is based on a reactive platform (triazatriangulenium salt) with an electrophilic center. Functional molecules are attached via C-C bond formation. The distance from the surface can be varied by a spacer, and the distance of the functional units from each other by the size of the platform. Self-assembly of the parent triazaangulenium salt as well as the functionalized platforms on Au(111) surfaces results in stable, hexagonally ordered adlayers.
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Affiliation(s)
- Belinda Baisch
- Institute of Experimental and Applied Physics, Christian-Albrechts-University Kiel, 24098 Kiel, Germany
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24
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Ahmed SAM. Photochromism of dihydroindolizines. Part 12: synthesis and photochromism of novel π-conjugated rigid dihydroindolizines as potential molecular electronic devices. Tetrahedron 2009. [DOI: 10.1016/j.tet.2008.12.047] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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25
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Ie Y, Hirose T, Yao A, Yamada T, Takagi N, Kawai M, Aso Y. Synthesis of tripodal anchor units bearing selenium functional groups and their adsorption behaviour on gold. Phys Chem Chem Phys 2009; 11:4949-51. [DOI: 10.1039/b906286f] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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26
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Wagner S, Leyssner F, Kördel C, Zarwell S, Schmidt R, Weinelt M, Rück-Braun K, Wolf M, Tegeder P. Reversible photoisomerization of an azobenzene-functionalized self-assembled monolayer probed by sum-frequency generation vibrational spectroscopy. Phys Chem Chem Phys 2009; 11:6242-8. [DOI: 10.1039/b823330f] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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27
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Shen C, Haryono M, Grohmann A, Buck M, Weidner T, Ballav N, Zharnikov M. Self-assembled monolayers of a bis(pyrazol-1-yl)pyridine-substituted thiol on Au(111). LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2008; 24:12883-12891. [PMID: 18950209 DOI: 10.1021/la8019974] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Self-assembled monolayers (SAMs) of a bis(pyrazol-1-yl)pyridine-substituted thiol (bpp-SH) on Au (111)/mica were studied with scanning tunneling microscopy (STM), X-ray photoelectron spectroscopy (XPS), and near-edge X-ray absorption fine structure spectroscopy (NEXAFS). Using substrates precoated with perylene-3,4,9,10-tetracarboxylic acid dianhydride (PTCDA), preparation at elevated temperatures yields highly ordered layers whose structure is described by a rectangular (5 x radical3) unit cell containing one molecule. The bis(pyrazol-1-yl)pyridine (bpp) units exhibit pi-stacking along the 112 direction, and they are tilted significantly. We conclude the three imine nitrogen atoms in the bpp headgroup adopt a trans,trans arrangement.
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Affiliation(s)
- Cai Shen
- EaStCHEM School of Chemistry, University of St. Andrews, St. Andrews KY16 9ST, United Kingdom
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28
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Jiao J, Schmidt I, Taniguchi M, Lindsey JS, Bocian DF. Comparison of electron-transfer rates for metal- versus ring-centered redox processes of porphyrins in monolayers on Au(111). LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2008; 24:12047-12053. [PMID: 18823081 DOI: 10.1021/la8019843] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The standard electron-transfer rate constants ( k ( 0 )) are measured for redox processes of Fe versus Zn porphyrins in monolayers on Au(111); the former undergoes a metal-centered redox process (conversion between Fe (III) and Fe (II) oxidation states) whereas the latter undergoes a ring-centered redox process (conversion between the neutral porphyrin and the pi-cation radical). Each porphyrin contains three meso-mesityl groups and a benzyl thiol for surface attachment. Under identical solvent (propylene carbonate)/electrolyte (1.0 M Bu 4NCl) conditions, the Zn (II) center has a coordinated Cl (-) ion when the porphyrin is in either the neutral or oxidized state. In the case of the Fe porphyrin, two species are observed a low-potential form ( E l (0) approximately -0.6 V) wherein the metal center has a coordinated Cl (-) ion when it is in either the Fe (II) or Fe (III) state and a high-potential form ( E h (0) approximately +0.2 V) wherein the metal center undergoes ligand exchange upon conversion from the Fe (III) to Fe (II) states. The k ( 0 ) values observed for all of the porphyrins depend on surface concentration, with higher concentrations resulting in slower rates, consistent with previous studies on porphyrin monolayers. The k ( 0 ) values for the ring-centered redox process (Zn chelate) are 10-40 times larger than those for the metal-centered process (Fe chelate); the k ( 0 ) values for the two forms of the Fe porphyrin differ by a factor of 2-4 (depending on surface concentration), the Cl (-) exchanging form generally exhibiting a faster rate. The faster rates for the ring- versus metal-centered redox process are attributed to the participating molecular orbitals and their proximity to the surface (given that the porphyrins are relatively upright on the surface): a pi molecular orbital that has significant electron density at the meso-carbon atoms (one of which is the site of attachment of the linker to the surface anchoring thiol) versus a d-orbital that is relatively well localized on the metal center.
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Affiliation(s)
- Jieying Jiao
- Department of Chemistry, University of California, Riverside, California 92521-0403, USA
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Bertin PA, Georganopoulou D, Liang T, Eckermann AL, Wunder M, Ahrens MJ, Blackburn GF, Meade TJ. Electroactive self-assembled monolayers on gold via bipodal dithiazepane anchoring groups. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2008; 24:9096-9101. [PMID: 18627193 DOI: 10.1021/la801165b] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Novel dithiazepane-functionalized ferrocenyl-phenylethynyl oligomers 1 and 2 have been synthesized. Self-assembled monolayers (SAMs) of these ferrocene derivatives have been studied by X-ray photoelectron spectroscopy, ellipsometry, and cyclic voltammetry. It has been shown by XPS that monolayers of the dithiazepane-anchored molecules on gold electrodes contain gold-thiolate species. Cyclic voltammetry of the SAMs were characteristic of stable electroactive monolayers even for single-component SAMs of 1 and 2, with the more ideal responses recorded for the two-component SAMs diluted with undecanethiol. The small variation in peak splittings at progressively higher scan rates in these SAMs makes dithiazepane-bridged redox species promising candidates for further studies on molecular wires with bipodal anchoring.
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31
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Lestini E, Nikitin K, Müller-Bunz H, Fitzmaurice D. Introducing Negative Charges into Bis-p-phenylene Crown Ethers: A Study of Bipyridinium-Based [2]Pseudorotaxanes and [2]Rotaxanes. Chemistry 2008; 14:1095-106. [DOI: 10.1002/chem.200700387] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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