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Lv L, Wang X, Ren H, Liu J, Zhu Y. Depressing behaviors and mechanism of an eco-friendly depressant on flotation separation of cassiterite and fluorite. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2020.114898] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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2
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Alharbi ARM, Andersson JM, Köper I, Andersson GG. Investigating the Structure of Self-Assembled Monolayers Related to Biological Cell Membranes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:14213-14221. [PMID: 31596586 DOI: 10.1021/acs.langmuir.9b02553] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Tethered bilayer lipid membranes are solid supported lipid membranes, where the inner leaflet is covalently linked to the solid supported substrate through anchorlipids. These anchorlipids form a self-assembled monolayer, which serves as the basis of the membrane and also provides submembrane space. The molecular structure and composition of this monolayer has thus significant influence on the membrane structural and functional properties. The density of the self-assembled monolayer can be tailored by adding small molecules to the monolayer. Here, the structure of fully tethered and sparsely tethered monolayers, where the anchorlipid has been diluted with a small surface-active thiol, has been analyzed using neutral impact collision ion scattering spectroscopy, X-ray photoelectron spectroscopy, and metastable induced electron spectroscopy. Combination of these three techniques allowed description of the self-assembly process in detail. The monolayers have been characterized in terms of layer thickness and orientation of the lipids.
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Affiliation(s)
| | - Jakob M Andersson
- Biosensor Technologies , Austrian Institute of Technology , 1210 Vienna , Austria
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3
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Karnes JJ, Gobrogge EA, Walker RA, Benjamin I. Unusual Structure and Dynamics at Silica/Methanol and Silica/Ethanol Interfaces—A Molecular Dynamics and Nonlinear Optical Study. J Phys Chem B 2015; 120:1569-78. [DOI: 10.1021/acs.jpcb.5b07777] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- John J. Karnes
- Department
of Chemistry and Biochemistry, University of California-Santa Cruz, Santa
Cruz, California 95064, United States
| | - Eric A. Gobrogge
- Department
of Chemistry and Biochemistry, Montana State University, Bozeman, Montana 59715, United States
| | - Robert A. Walker
- Department
of Chemistry and Biochemistry, Montana State University, Bozeman, Montana 59715, United States
| | - Ilan Benjamin
- Department
of Chemistry and Biochemistry, University of California-Santa Cruz, Santa
Cruz, California 95064, United States
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4
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Hintermair U, Sheehan SW, Parent AR, Ess DH, Richens DT, Vaccaro PH, Brudvig GW, Crabtree RH. Precursor Transformation during Molecular Oxidation Catalysis with Organometallic Iridium Complexes. J Am Chem Soc 2013; 135:10837-51. [DOI: 10.1021/ja4048762] [Citation(s) in RCA: 181] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
- Ulrich Hintermair
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United
States
| | - Stafford W. Sheehan
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United
States
| | - Alexander R. Parent
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United
States
| | - Daniel H. Ess
- Department of Chemistry & Biochemistry, Brigham Young University, Provo, Utah 84602, United States
| | - David T. Richens
- Department of Chemistry & Biochemistry, New Mexico State University, Las Cruces, New Mexico 88003, United States
| | - Patrick H. Vaccaro
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United
States
| | - Gary W. Brudvig
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United
States
| | - Robert H. Crabtree
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United
States
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5
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Kubota J, Kusafuka K, Wada A, Domen K, Kano SS. Time-resolved sum-frequency generation spectroscopy of methoxy and deuterated methoxy on Ni(111) using near-infrared laser pulses. J Phys Chem B 2006; 110:10785-91. [PMID: 16771327 DOI: 10.1021/jp060699g] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Methoxy (CH3O-) and deuterated (d-) methoxy (CD3O-) species on Ni(111) are investigated by sum-frequency generation (SFG) spectroscopy. Methoxy adsorbed on the Ni(111) surface is confirmed by SFG spectroscopy to be oriented normal to the surface. Two resonant peaks produced by methoxy, at 2921 and 2821 cm(-1), are assigned to Fermi resonance between the CH symmetric stretching and overtone modes. Deuterated methoxy exhibits a single strong peak at 2051 cm(-1) assigned to the CD symmetric stretching mode. Investigation of the sub-nanosecond transient behavior of methoxy and d-methoxy species on Ni(111) under short-pulse laser pumping at 1064 nm reveals a clear weakening and recovery of the SFG peaks upon heating. The observed temporal profile is reproduced by simulation assuming that the original methoxy in the ground state is in chemical equilibrium with a new state produced by instantaneous heating. The dependence of the SFG spectra on the initial substrate temperature is also reproduced by the simulation. The simulation suggests a temperature jump of 250 K upon laser pumping, inducing a change in the molecular orientation or adsorption site of methoxy on the Ni(111) surface without decomposition of methoxy to adsorbed CO and hydrogen, which occurs under normal heating at 200 K.
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Affiliation(s)
- Jun Kubota
- Chemical Resources Laboratory, Tokyo Institute of Technology, 4259 Nagatsuda, Midori-ku, Yokohama 226-8503, Japan.
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Barros RB, Garcia AR, Ilharco LM. Adsorption of [D2]Methanol on Ru(001)O Surfaces: The Influence of Preadsorbed Oxygen on the Methoxide Geometry. Chemphyschem 2005; 6:1299-306. [PMID: 15968697 DOI: 10.1002/cphc.200400546] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The influence of oxygen precoverage on the bonding geometry of methoxide on Ru(001) was studied using the isotopically labeled molecule CHD2OH by reflection-absorption infrared spectroscopy (RAIRS). This molecule is an excellent model because the vibrational spectra of CHD2O- may be unambiguously correlated with the adsorption configuration. For Ru(001)--O layers with an effective oxygen coverage (theta0) between 0.25 and 0.6 ML (ML=monolayer), the influence of the oxygen precoverage was shown to vary with the initial methanol exposure. For an extremely low dose of [D2]methanol (0.01 L; L=Langmuir, 1 L=10(-6) torr s), at 90 K, no oxygen-coverage effects were detected on the geometry of [D2]methoxide: it adsorbs in an upright orientation (pseudo-C(3v) local symmetry), just as on clean Ru(001). An increase in the methanol exposure to 0.1 L, at the same temperature, results in the formation of a disordered layer of tilted methoxide: for theta(O)=0.25 ML, C(s)/C1 and intrinsic C1 configurations are present on the surface, whereas for theta(O)> or =0.5 ML, only the former species were identified. The thermal activation of these tilted layers to 105 K results in a lower coverage of upright methoxide for any oxygen precoverage, coadsorbed with decomposition products, as confirmed by the detection of adsorbed formaldehyde and, on the denser oxygen layer (theta(O)=0.6 ML), formate. The influence of the oxygen precoverage becomes determinant when annealing a [D2]methanol multilayer to 105 K: for theta(O)=0.25 ML, the RAIR spectrum correlates with a disordered layer of tilted methoxide and formaldehyde, whereas for theta(O)=0.6 ML upright methoxide, formate, and carbon monoxide were identified. On clean Ru(001), for methanol exposures > or =0.1 L, the C(3v) methoxide configuration was never attained upon thermal activation.
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Affiliation(s)
- Ricardo B Barros
- Centro de Química-Física Molecular, Complexo I, Instituto Superior Técnico, Av. Rovisco Pais 1, 1049-001 Lisboa, Portugal
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7
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Vinod CP, Niemantsverdriet JW, Nieuwenhuys BE. Decomposition of methanol on Au(310). Phys Chem Chem Phys 2005; 7:1824-9. [DOI: 10.1039/b500094g] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Kang DH, Friend CM. Sensitivity of methyl thiolate desulfurization selectivity to reaction temperature and hydroxyl coverage. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2004; 20:11443-11449. [PMID: 15595768 DOI: 10.1021/la048822n] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The adsorption and reaction of methanethiol (CH3SH) and dimethyl disulfide (CH3SSCH3) on Mo(110)-(1 x 6)-O have been studied using temperature-programmed reaction spectroscopy and reflection-absorption infrared spectroscopy over the temperature range of 110-550 K. The S-H bond is broken upon adsorption to form adsorbed OH, water, and methyl thiolate (CH3S-) at low temperature. Water is evolved at 210 and 310 K via molecular desorption and disproportionation of OH, respectively. Some hydroxyl remains on the surface up to 350 K. Methyl thiolate is also formed from CH3SSCH3 on Mo(110)-(1 x 6)-O. Methyl thiolate undergoes C-S cleavage above 300 K, yielding methane and methyl radicals. There is also a minor amount of nonselective decomposition leading to the formation of carbon and hydrogen. Methane production is promoted by adsorbed hydroxyl. As the hydroxyl coverage increases, the yield of methyl radicals relative to methane diminishes. Accordingly, there is more methane produced from methanethiol reaction than from dimethyl disulfide, since S-H dissociation in CH3SH produces OH. The maximum coverage of the thiolate is approximately 0.5 monolayers, based on the amount of sulfur remaining after reaction measured by Auger electron spectroscopy. In contrast to cyclopropylmethanethiol (c-C3H5CH2SH), for which alkyl transfer from sulfur to oxygen is observed, there is no evidence for transfer of the methyl group of methyl thiolate to oxygen on the surface. Specifically, there is no evidence for methoxy (CH3O-) in infrared spectroscopy or temperature-programmed reaction experiments.
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Affiliation(s)
- D H Kang
- Department of Chemistry & Division of Engineering & Applied Sciences, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, USA
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Barros RB, Garcia AR, Ilharco LM. Effect of Oxygen Precoverage on the Reactivity of Methanol on Ru(001) Surfaces. J Phys Chem B 2004. [DOI: 10.1021/jp049688i] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Ricardo B. Barros
- Centro de Química-Física Molecular, Complexo I, Instituto Superior Técnico, Av. Rovisco Pais 1, 1049−001 Lisboa, Portugal
| | - Ana Rosa Garcia
- Centro de Química-Física Molecular, Complexo I, Instituto Superior Técnico, Av. Rovisco Pais 1, 1049−001 Lisboa, Portugal
| | - Laura M. Ilharco
- Centro de Química-Física Molecular, Complexo I, Instituto Superior Técnico, Av. Rovisco Pais 1, 1049−001 Lisboa, Portugal
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10
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Pratt SJ, Escott DK, King DA. Multilayer growth and chemisorbate reactivity of methanol on Pd{110}. J Chem Phys 2003. [DOI: 10.1063/1.1620993] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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11
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Kretzschmar I, Friend CM. Kinetic Control of Surface Reactions: Regioselectivity in the Reaction of 2-Methylcyclopropylmethanol on Mo(110)−(6×1)−O. J Phys Chem B 2002. [DOI: 10.1021/jp020937h] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Ilona Kretzschmar
- Department of Chemistry, Harvard University, Cambridge, Massachusetts 02138
| | - C. M. Friend
- Department of Chemistry, Harvard University, Cambridge, Massachusetts 02138
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12
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Jakob P. Investigation of one- and two-dimensional vibrational density of states using two-phonon infrared absorption spectroscopy. J Chem Phys 2001. [DOI: 10.1063/1.1343837] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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14
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Comparative study of geometry and bonding character for methoxy radical adsorption on noble metals. ACTA ACUST UNITED AC 2000. [DOI: 10.1016/s0166-1280(99)00286-9] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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15
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Mudalige K, Warren S, Trenary M. Vibrational Analysis of a Chemisorbed Polyatomic Molecule: Methoxy on Cu(100). J Phys Chem B 2000. [DOI: 10.1021/jp9933121] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Kanchana Mudalige
- Department of Chemistry, University of Illinois at Chicago, 845 W. Taylor Street, Chicago, Illinois 60607-7061
| | - Samantha Warren
- Department of Chemistry, University of Illinois at Chicago, 845 W. Taylor Street, Chicago, Illinois 60607-7061
| | - Michael Trenary
- Department of Chemistry, University of Illinois at Chicago, 845 W. Taylor Street, Chicago, Illinois 60607-7061
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Ásmundsson R, Uvdal P. Fermi resonance coupling in a surface adsorbate: The C–H stretch in methoxy adsorbed on Cu(100) calculations and experiments. J Chem Phys 2000. [DOI: 10.1063/1.480635] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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17
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Queeney KT, Friend CM. Site-Selective Surface Reactions: Hydrocarbon Oxidation Processes on Oxidized Mo(110). J Phys Chem B 1999. [DOI: 10.1021/jp991994m] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- K. T. Queeney
- Harvard University, Department of Chemistry, 12 Oxford Street, Cambridge, Massachusetts 02138
| | - C. M. Friend
- Harvard University, Department of Chemistry, 12 Oxford Street, Cambridge, Massachusetts 02138
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18
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Queeney KT, Friend CM. Competing pathways for methoxy decomposition on oxygen-covered Mo(110). J Chem Phys 1998. [DOI: 10.1063/1.477232] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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19
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Chen DA, Friend CM. Changing Reactivity of a Bimetallic Surface via Oxidation: Reactions of Methanol on Oxygen-Covered Co Thin Films. J Phys Chem B 1998. [DOI: 10.1021/jp971127m] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- D. A. Chen
- Department of Chemistry, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138
| | - C. M. Friend
- Department of Chemistry, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138
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Queeney KT, Chen DA, Friend CM. Probing the Role of Oxygen Coordination in Hydrocarbon Oxidation: Methyl Radical Addition to Oxygen on Mo(110). J Am Chem Soc 1997. [DOI: 10.1021/ja9707771] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- K. T. Queeney
- Department of Chemistry, Harvard University Cambridge, Massachusetts 02138
| | - D. A. Chen
- Department of Chemistry, Harvard University Cambridge, Massachusetts 02138
| | - C. M. Friend
- Department of Chemistry, Harvard University Cambridge, Massachusetts 02138
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21
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Chen DA, Friend CM. Competition between C−O Bond Scission and Retention in Methanol Reaction on Co-Covered Mo(110). J Phys Chem B 1997. [DOI: 10.1021/jp9709417] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- D. A. Chen
- Department of Chemistry, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138
| | - C. M. Friend
- Department of Chemistry, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138
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Chen DA, Friend CM. Alcohol Chemistry as a Probe of Mixed-Metal Phases: Reactions of 2-Propanol on Cobalt-Covered Mo(110). ACTA ACUST UNITED AC 1996. [DOI: 10.1021/jp9621989] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- D. A. Chen
- Department of Chemistry, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138
| | - C. M. Friend
- Department of Chemistry, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138
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Weldon MK, Friend CM. Probing Surface Reaction Mechanisms Using Chemical and Vibrational Methods: Alkyl Oxidation and Reactivity of Alcohols on Transitions Metal Surfaces. Chem Rev 1996; 96:1391-1412. [PMID: 11848795 DOI: 10.1021/cr950224d] [Citation(s) in RCA: 92] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Marcus K. Weldon
- Department of Chemistry, Harvard University, Cambridge, Massachusetts 02138Department of Chemistry
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Queeney KT, Arumainayagam CR, Weldon MK, Friend CM, Blumberg MQ. Differential Reactivity and Structure of Mono- and Dialkoxides: The Reactions of Ethylene Glycol on Mo(110). J Am Chem Soc 1996. [DOI: 10.1021/ja953987r] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- K. T. Queeney
- Contribution from the Departments of Chemistry, Harvard University, Cambridge, Massachusetts 02138, and Wellesley College, Wellesley, Massachusetts 02181
| | - C. R. Arumainayagam
- Contribution from the Departments of Chemistry, Harvard University, Cambridge, Massachusetts 02138, and Wellesley College, Wellesley, Massachusetts 02181
| | - M. K. Weldon
- Contribution from the Departments of Chemistry, Harvard University, Cambridge, Massachusetts 02138, and Wellesley College, Wellesley, Massachusetts 02181
| | - C. M. Friend
- Contribution from the Departments of Chemistry, Harvard University, Cambridge, Massachusetts 02138, and Wellesley College, Wellesley, Massachusetts 02181
| | - M. Q. Blumberg
- Contribution from the Departments of Chemistry, Harvard University, Cambridge, Massachusetts 02138, and Wellesley College, Wellesley, Massachusetts 02181
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Uvdal P, Weldon MK, Friend CM. Surface-induced bond anharmonicity probed through a two-phonon bound state: Methoxide adsorbed on Mo(110). PHYSICAL REVIEW. B, CONDENSED MATTER 1996; 53:5007-5010. [PMID: 9984063 DOI: 10.1103/physrevb.53.5007] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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