201
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Pradzynski CC, Forck RM, Zeuch T, Slavicek P, Buck U. A Fully Size-Resolved Perspective on the Crystallization of Water Clusters. Science 2012; 337:1529-32. [DOI: 10.1126/science.1225468] [Citation(s) in RCA: 154] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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202
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Ebben CJ, Shrestha M, Martinez IS, Corrigan AL, Frossard AA, Song WW, Worton DR, Petäjä T, Williams J, Russell LM, Kulmala M, Goldstein AH, Artaxo P, Martin ST, Thomson RJ, Geiger FM. Organic constituents on the surfaces of aerosol particles from Southern Finland, Amazonia, and California studied by vibrational sum frequency generation. J Phys Chem A 2012; 116:8271-90. [PMID: 22734593 DOI: 10.1021/jp302631z] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
This article summarizes and compares the analysis of the surfaces of natural aerosol particles from three different forest environments by vibrational sum frequency generation. The experiments were carried out directly on filter and impactor substrates, without the need for sample preconcentration, manipulation, or destruction. We discuss the important first steps leading to secondary organic aerosol (SOA) particle nucleation and growth from terpene oxidation by showing that, as viewed by coherent vibrational spectroscopy, the chemical composition of the surface region of aerosol particles having sizes of 1 μm and lower appears to be close to size-invariant. We also discuss the concept of molecular chirality as a chemical marker that could be useful for quantifying how chemical constituents in the SOA gas phase and the SOA particle phase are related in time. Finally, we describe how the combination of multiple disciplines, such as aerosol science, advanced vibrational spectroscopy, meteorology, and chemistry can be highly informative when studying particles collected during atmospheric chemistry field campaigns, such as those carried out during HUMPPA-COPEC-2010, AMAZE-08, or BEARPEX-2009, and when they are compared to results from synthetic model systems such as particles from the Harvard Environmental Chamber (HEC). Discussions regarding the future of SOA chemical analysis approaches are given in the context of providing a path toward detailed spectroscopic assignments of SOA particle precursors and constituents and to fast-forward, in terms of mechanistic studies, through the SOA particle formation process.
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Affiliation(s)
- Carlena J Ebben
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
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203
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Diehl A, dos Santos AP, Levin Y. Surface tension of an electrolyte-air interface: a Monte Carlo study. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2012; 24:284115. [PMID: 22739036 DOI: 10.1088/0953-8984/24/28/284115] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We present a new method for calculating the surface tension of an electrolyte-air interface using Monte Carlo (MC) simulations with an implicit solvent in a spherical drop geometry. The boundary conditions for the electric field at the interface are accounted for using image and counter-image charges. The density profiles obtained from the simulations are used to calculate the excess surface tension of the electrolyte-air interface using the Gibbs adsorption isotherm equation. The results are found to be in good agreement with experiments and the earlier theoretical calculations.
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Affiliation(s)
- Alexandre Diehl
- Departamento de Física, Instituto de Física e Matemática, Universidade Federal de Pelotas, Caixa Postal 354, CEP 96010-900, Pelotas, RS, Brazil
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204
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Martins-Costa MTC, Anglada JM, Francisco JS, Ruiz-Lopez MF. Reactivity of Volatile Organic Compounds at the Surface of a Water Droplet. J Am Chem Soc 2012; 134:11821-7. [DOI: 10.1021/ja304971e] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- Marilia T. C. Martins-Costa
- Theoretical Chemistry and Biochemistry
group, SRSMC, CNRS, University of Lorraine, BP 70239, 54506, Vandoeuvre-les-Nancy, France
| | - Josep M. Anglada
- Departament de Química
Biològica i Modelització Molecular, IQAC-CSIC, c/Jordi Girona 18, 08034 Barcelona, Spain
| | - Joseph S. Francisco
- Department of Chemistry and Department
of Earth and Atmospheric Science, Purdue University, West Lafayette, Indiana 47907-2084, United States
| | - Manuel F. Ruiz-Lopez
- Theoretical Chemistry and Biochemistry
group, SRSMC, CNRS, University of Lorraine, BP 70239, 54506, Vandoeuvre-les-Nancy, France
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205
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Abstract
For more than two decades a cadre of physical chemists has focused on understanding the formation processes, chemical composition, and chemical kinetics of atmospheric aerosol particles and droplets with diameters ranging from a few nanometers to ∼10,000 nm. They have adapted or invented a range of fundamental experimental and theoretical tools to investigate the thermochemistry, mass transport, and chemical kinetics of processes occurring at nanoscale gas-liquid and gas-solid interfaces for a wide range of nonideal, real-world substances. State-of-the-art laboratory methods devised to study molecular spectroscopy, chemical kinetics, and molecular dynamics also have been incorporated into field measurement instruments that are deployed routinely on research aircraft, ships, and mobile laboratories as well as at field sites from megacities to the most remote jungle, desert, and polar locations. These instruments can now provide real-time, size-resolved aerosol particle physical property and chemical composition data anywhere in Earth's troposphere and lower stratosphere.
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Affiliation(s)
| | - Douglas R. Worsnop
- Center for Aerosol and Cloud Chemistry, Aerodyne Research, Inc., Billerica, Massachusetts 01821-3976
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206
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Enami S, Mishra H, Hoffmann MR, Colussi AJ. Hofmeister effects in micromolar electrolyte solutions. J Chem Phys 2012; 136:154707. [PMID: 22519343 DOI: 10.1063/1.4704752] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Affiliation(s)
- Shinichi Enami
- The Hakubi Center, Kyoto University, Kyoto 606-8302, Japan.
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207
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Ciuraru R, Gosselin S, Visez N, Petitprez D. Heterogeneous reactivity of chlorine atoms with ammonium sulfate and ammonium nitrate particles. Phys Chem Chem Phys 2012; 14:4527-37. [PMID: 22374517 DOI: 10.1039/c2cp23455f] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
In this laboratory study, model particles of ammonium sulfate (AS) and ammonium nitrate (AN) were exposed to chlorine atoms and uptake experiments were performed in a coated wall flow tube reactor coupled to a molecular beam mass spectrometer. The reactive surfaces were prepared by coating the inner surface of the reactor using two different methods: either by depositing size-selected particles on the halocarbon wax or by spray depositing thin films using a constant output atomizer. The observed uptake coefficients vary for (NH(4))(2)SO(4), ranging from γ(Cl)(AS)≈ 1 × 10(-3) for size-selected particles to γ(Cl)(AS)≈ 6 × 10(-2) for thin films prepared by spray. An uptake coefficient of γ(Cl)(AN)≈ 2.5 × 10(-3) of Cl˙ on size-selected NH(4)NO(3) particles was measured. A heterogeneous recombination of Cl atoms to from Cl(2) molecules was observed for the two surfaces. Furthermore, an ageing process was observed for AS particles, this phenomenon leading to the formation of new chlorine species on the solid substrate.
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Affiliation(s)
- Raluca Ciuraru
- Laboratoire de Physico-Chimie des Processus de Combustion et de l'Atmosphère, UMR CNRS Lille, Université Lille1-Sciences et Technologies, France
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208
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209
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Liu XY, Mu XR, Liu Y, Liu HJ, Chen Y, Cheng F, Jiang SC. Hyperbranched polymers with thermoresponsive property highly sensitive to ions. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:4867-4876. [PMID: 22356606 DOI: 10.1021/la300046w] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The salt effects on the water solubility of thermoresponsive hyperbranched polyethylenimine and polyamidoamine possessing large amounts of isobutyramide terminal groups (HPEI-IBAm and HPAMAM-IBAm) were studied systematically. Eight anions with sodium as the counterion and ten cations with chloride as the counterion were used to measure the anion and cation effects on the cloud point temperature (T(cp)) of these dendritic polymers in water. It was found that the T(cp) of these dendritic polymers was much more sensitive to the addition of salts than that of the traditional thermoresponsive linear polymers. At low anion concentration, the electrostatic interaction between anions and the positively charged groups of these polymers was dominant, resulting in the unusual anion effect on the T(cp) of these polymers in water, including (1) T(cp) of these dendritic polymers decreasing nonlinearly with the increase of kosmotropic anion concentration; (2) the chaotropic anions showing abnormal salting-out property at low salt concentration and the stronger chaotropes having much pronounced salting-out ability; (3) anti-Hofmeister ordering at low salt concentration. At moderate to high salt concentration, the specific ranking of these anions in reducing the T(cp) of HPEI-IBAm and HPAMAM-IBAm polymers was PO(4)(3-) > CO(3)(2-) > SO(4)(2-) > S(2)O(3)(2-) > F(-) > Cl(-) > Br(-) > I(-), in accordance with the well-known Hofmeister series. At moderate to high salt concentration, the specific ranking order of inorganic cations in reducing the T(cp) of HPEI-IBAm polymer was Sr(2+) ≈ Ba(2+) > Na(+) ≈ K(+) ≈ Rb(+) > Cs(+) > NH(4)(+) ≈ Ca(2+) > Li(+) ≈ Mg(2+). This sequence was only partially similar to the typical Hofmeister cation series, whereas at low salt concentration the cation effect on T(cp) of the dendritic polymer was insignificant and no obvious specific ranking order could be found.
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Affiliation(s)
- Xun-Yong Liu
- School of Chemistry and Materials Science, Ludong University, Yantai, Shandong, People's Republic of China
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210
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Peng T, Nguyen AV, Peng H, Dang LX. Quantitative Analysis of Aqueous Nanofilm Rupture by Molecular Dynamic Simulation. J Phys Chem B 2012; 116:1035-42. [DOI: 10.1021/jp208896y] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Tiefeng Peng
- School of Chemical Engineering, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Anh V. Nguyen
- School of Chemical Engineering, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Hong Peng
- School of Chemical Engineering, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Liem X. Dang
- Pacific Northwest National Laboratory, Richland, Washington 99352, United States
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211
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Elucidating the mechanism of selective ion adsorption to the liquid water surface. Proc Natl Acad Sci U S A 2012; 109:701-5. [PMID: 22233805 DOI: 10.1073/pnas.1116169109] [Citation(s) in RCA: 148] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Adsorption of aqueous thiocyanate ions from bulk solution to the liquid/vapor interface was measured as a function of temperature by resonant UV second harmonic generation spectroscopy. The resulting adsorption enthalpy and entropy changes of this prototypical chaotrope were both determined to be negative. This surprising result is supported by molecular simulations, which clarify the microscopic origins of observed thermodynamic changes. Calculations reveal energetic influences of adsorbed ions on their surroundings to be remarkably local. Negative adsorption enthalpies thus reflect a simple repartitioning of solvent density among surface, bulk, and coordination regions. A different, and much less spatially local, mechanism underlies the concomitant loss of entropy. Simulations indicate that ions at the interface can significantly bias surface height fluctuations even several molecular diameters away, imposing restrictions consistent with the scale of measured and computed adsorption entropies. Based on these results, we expect an ion's position in the Hofmeister lyotropic series to be determined by a combination of driving forces associated with the pinning of capillary waves and with a competition between ion hydration energy and the neat liquid's surface tension.
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212
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Goncharuk VV, Lapshin VB, Chichaeva MA, Syroezhkin AV. The atmosphere as a colloid system. J WATER CHEM TECHNO+ 2012. [DOI: 10.3103/s1063455x11060014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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213
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Valsaraj KT. A Review of the Aqueous Aerosol Surface Chemistry in the Atmospheric Context. ACTA ACUST UNITED AC 2012. [DOI: 10.4236/ojpc.2012.21008] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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214
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Otten D, Onorato R, Michaels R, Goodknight J, Saykally R. Strong surface adsorption of aqueous sodium nitrite as an ion pair. Chem Phys Lett 2012. [DOI: 10.1016/j.cplett.2011.10.056] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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215
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Bunkin NF, Yurchenko SO, Suyazov NV, Shkirin AV. Structure of the nanobubble clusters of dissolved air in liquid media. J Biol Phys 2012; 38:121-52. [PMID: 23277675 PMCID: PMC3285720 DOI: 10.1007/s10867-011-9242-8] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2011] [Accepted: 09/27/2011] [Indexed: 11/26/2022] Open
Abstract
A qualitative model of the nucleation of stable bubbles in water at room temperature is suggested. This model is completely based on the property of the affinity of water at the nanometer scale; it is shown that under certain conditions the extent of disorder in a liquid starts growing, which results in a spontaneous decrease of the local density of the liquid and in the formation of nanometer-sized voids. These voids can serve as nuclei for the following generation of the so-called bubstons (the abbreviation for bubbles, stabilized by ions). The model of charging the bubstons by the ions, which are capable of adsorption, and the screening by a cloud of counter-ions, which are incapable of adsorption, is analyzed. It was shown that, subject to the charge of bubston, two regimes of such screening can be realized. At low charge of bubston the screening is described in the framework of the known linearized Debye-Huckel approach, when the sign of the counter-ion cloud preserves its sign everywhere in the liquid surrounding the bubston, whereas at large charge this sign is changed at some distance from the bubston surface. This effect provides the mechanism of the emergence of two types of compound particles having the opposite polarity, which leads to the aggregation of such compound particles by a ballistic kinetics.
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Affiliation(s)
- Nikolai F. Bunkin
- A.M.Prokhorov General Physics Institute of Russian Academy of Sciences, Vavilova str. 38, Moscow, 119991 Russia
| | - Stanislav O. Yurchenko
- Bauman Moscow State Technical University, 2-nd Baumanskaya str. 5, Moscow, 105005 Russia
| | - Nikolai V. Suyazov
- A.M.Prokhorov General Physics Institute of Russian Academy of Sciences, Vavilova str. 38, Moscow, 119991 Russia
| | - Alexey V. Shkirin
- A.M.Prokhorov General Physics Institute of Russian Academy of Sciences, Vavilova str. 38, Moscow, 119991 Russia
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216
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Funkner S, Niehues G, Schmidt DA, Heyden M, Schwaab G, Callahan KM, Tobias DJ, Havenith M. Watching the low-frequency motions in aqueous salt solutions: the terahertz vibrational signatures of hydrated ions. J Am Chem Soc 2011; 134:1030-5. [PMID: 22124334 DOI: 10.1021/ja207929u] [Citation(s) in RCA: 154] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The details of ion hydration still raise fundamental questions relevant to a large variety of problems in chemistry and biology. The concept of water "structure breaking" and "structure making" by ions in aqueous solutions has been invoked to explain the Hofmeister series introduced over 100 years ago, which still provides the basis for the interpretation of experimental observations, in particular the stabilization/destabilization of biomolecules. Recent studies, using state-of-the-art experiments and molecular dynamics simulations, either challenge or support some key points of the structure maker/breaker concept, specifically regarding long-ranged ordering/disordering effects. Here, we report a systematic terahertz absorption spectroscopy and molecular dynamics simulation study of a series of aqueous solutions of divalent salts, which adds a new piece to the puzzle. The picture that emerges from the concentration dependence and assignment of the observed absorption features is one of a limited range of ion effects that is confined to the first solvation shell.
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Affiliation(s)
- Stefan Funkner
- Department of Physical Chemistry II, Ruhr-University Bochum, 44780 Bochum, Germany
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217
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Willow SY, Singh NJ, Kim KS. NH4+ Resides Inside the Water 20-mer Cage As Opposed to H3O+, Which Resides on the Surface: A First Principles Molecular Dynamics Simulation Study. J Chem Theory Comput 2011; 7:3461-5. [DOI: 10.1021/ct200486c] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Soohaeng Yoo Willow
- Center for Superfunctional Materials, Department of Chemistry, Pohang University of Science and Technology, San 31, Hyojadong, Namgu, Pohang 790-784, Korea
| | - N. Jiten Singh
- Center for Superfunctional Materials, Department of Chemistry, Pohang University of Science and Technology, San 31, Hyojadong, Namgu, Pohang 790-784, Korea
| | - Kwang S. Kim
- Center for Superfunctional Materials, Department of Chemistry, Pohang University of Science and Technology, San 31, Hyojadong, Namgu, Pohang 790-784, Korea
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218
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Park SW, Kim CW, Lee JH, Shim G, Kim KS. Comparison of Arsenic Acid with Phosphoric Acid in the Interaction with a Water Molecule and an Alkali/Alkaline-Earth Metal Cation. J Phys Chem A 2011; 115:11355-61. [DOI: 10.1021/jp2051245] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- Sung Woo Park
- Center for Superfunctional Materials, Department of Chemistry, Pohang University of Science and Technology, San 31, Hyojadong, Namgu, Pohang 790-784, Korea
| | - Chang Woo Kim
- Center for Superfunctional Materials, Department of Chemistry, Pohang University of Science and Technology, San 31, Hyojadong, Namgu, Pohang 790-784, Korea
| | - Ji Hyun Lee
- Center for Superfunctional Materials, Department of Chemistry, Pohang University of Science and Technology, San 31, Hyojadong, Namgu, Pohang 790-784, Korea
| | - Giwoong Shim
- Center for Superfunctional Materials, Department of Chemistry, Pohang University of Science and Technology, San 31, Hyojadong, Namgu, Pohang 790-784, Korea
| | - Kwang S. Kim
- Center for Superfunctional Materials, Department of Chemistry, Pohang University of Science and Technology, San 31, Hyojadong, Namgu, Pohang 790-784, Korea
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219
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220
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Hiranuma Y, Kaniwa K, Shoji M, Mafuné F. Solvation structures of iodide on and below a surface of aqueous solution studied by photodetachment spectroscopy. J Phys Chem A 2011; 115:8493-7. [PMID: 21721573 DOI: 10.1021/jp204195t] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We investigated solvation structures of I(-) on and below a surface of an aqueous solution by photodetachment spectroscopy. An aqueous solution of an alkali halide was introduced to the vacuum as a continuous liquid flow (liquid beam), and the liquid beam was irradiated with a UV laser pulse. The intensity of electrons emitted from the surface by the laser excitation was measured as a function of wavelength (photodetachment spectroscopy), and we obtained absorption spectrum of I(-) on and below the solution surface. From the absorption spectrum, we found that I(-) starts to appear on the solution surface as the bulk NaI concentration increases. Similar concentration dependence was observed for the KI solution. We also found that I(-) located inside the solution is pushed to the surface, when NaCl is added to the solution. These changes are explained in terms of the difference in the polarizability of halide ions.
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Affiliation(s)
- Yojiro Hiranuma
- Department of Basic Science, Graduate School of Arts and Sciences, The University of Tokyo, Komaba, Tokyo 153-8902, Japan
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221
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Hua W, Chen X, Allen HC. Phase-Sensitive Sum Frequency Revealing Accommodation of Bicarbonate Ions, and Charge Separation of Sodium and Carbonate Ions within the Air/Water Interface. J Phys Chem A 2011; 115:6233-8. [DOI: 10.1021/jp111552f] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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222
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Ahadi E, Konermann L. Ejection of Solvated Ions from Electrosprayed Methanol/Water Nanodroplets Studied by Molecular Dynamics Simulations. J Am Chem Soc 2011; 133:9354-63. [DOI: 10.1021/ja111492s] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Elias Ahadi
- Department of Chemistry, The University of Western Ontario, London, Ontario N6A 5B7, Canada
| | - Lars Konermann
- Department of Chemistry, The University of Western Ontario, London, Ontario N6A 5B7, Canada
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223
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Siefermann KR, Abel B. The Hydrated Electron: A Seemingly Familiar Chemical and Biological Transient. Angew Chem Int Ed Engl 2011; 50:5264-72. [DOI: 10.1002/anie.201006521] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2010] [Revised: 02/15/2011] [Indexed: 11/05/2022]
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224
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Siefermann KR, Abel B. Das hydratisierte Elektron - eine scheinbar vertraute transiente Spezies in chemischen und biologischen Systemen. Angew Chem Int Ed Engl 2011. [DOI: 10.1002/ange.201006521] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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225
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Ota ST, Richmond GL. Chilling out: a cool aqueous environment promotes the formation of gas-surface complexes. J Am Chem Soc 2011; 133:7497-508. [PMID: 21520889 DOI: 10.1021/ja201027k] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
SO(2), an important atmospheric pollutant, has been implicated in environmental phenomena such as acid rain, climate change, and cloud formation. In addition, SO(2) is fundamentally interesting because it forms spectroscopically identifiable complexes with water at aqueous surfaces. Vibrational sum frequency spectroscopy (VSFS) is used here to further investigate the mechanism by which SO(2) adsorbs to water at tropospherically relevant temperatures (0-23 °C). The spectral results lead to two important conclusions. SO(2) surface affinity is enhanced at colder temperatures, with nearly all of the topmost water molecules showing evidence of binding to SO(2) at 0 °C as compared to a much lower fraction at room temperature. This surface adsorption results in significant changes in water orientation at the surface, but is reversible at the temperatures examined here. Second, the SO(2) complex formation at aqueous surfaces is independent of aqueous solution acidity. One challenge in previous uptake studies was the ability to distinguish between the effects of surface adsorption as compared to bulk accommodation. The surface and vibrational specificity of these studies make this distinction possible, allowing a selective study of how the aqueous properties temperature and pH influence SO(2) surface affinity.
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Affiliation(s)
- Stephanie T Ota
- Department of Chemistry, University of Oregon, Eugene, Oregon 97403, USA
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226
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Caleman C, Hub JS, van Maaren PJ, van der Spoel D. Atomistic simulation of ion solvation in water explains surface preference of halides. Proc Natl Acad Sci U S A 2011; 108:6838-6842. [PMCID: PMC3084043 DOI: 10.1073/pnas.1017903108] [Citation(s) in RCA: 163] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2024] Open
Abstract
Water is a demanding partner. It strongly attracts ions, yet some halide anions—chloride, bromide, and iodide—are expelled to the air/water interface. This has important implications for chemistry in the atmosphere, including the ozone cycle. We present a quantitative analysis of the energetics of ion solvation based on molecular simulations of all stable alkali and halide ions in water droplets. The potentials of mean force for Cl-, Br-, and I- have shallow minima near the surface. We demonstrate that these minima derive from more favorable water–water interaction energy when the ions are partially desolvated. Alkali cations are on the inside because of the favorable ion–water energy, whereas F- is driven inside by entropy. Models attempting to explain the surface preference based on one or more ion properties such as polarizability or size are shown to lead to qualitative and quantitative errors, prompting a paradigm shift in chemistry away from such simplifications.
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Affiliation(s)
- Carl Caleman
- Center for Free-Electron Laser Science, Deutsches Elektronen-Synchrotron, Notkestraße 85, DE-22607 Hamburg, Germany; and
| | - Jochen S. Hub
- Department of Cell and Molecular Biology, Biomedical Center, Box 596, Uppsala University, SE-75 124 Uppsala, Sweden
| | - Paul J. van Maaren
- Department of Cell and Molecular Biology, Biomedical Center, Box 596, Uppsala University, SE-75 124 Uppsala, Sweden
| | - David van der Spoel
- Department of Cell and Molecular Biology, Biomedical Center, Box 596, Uppsala University, SE-75 124 Uppsala, Sweden
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227
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Hayase S, Yabushita A, Kawasaki M, Enami S, Hoffmann MR, Colussi AJ. Weak Acids Enhance Halogen Activation on Atmospheric Water’s Surfaces. J Phys Chem A 2011; 115:4935-40. [DOI: 10.1021/jp2021775] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Sayaka Hayase
- Department of Molecular Engineering, Kyoto University, Kyoto 615-8510, Japan
| | - Akihiro Yabushita
- Department of Molecular Engineering, Kyoto University, Kyoto 615-8510, Japan
| | - Masahiro Kawasaki
- Department of Molecular Engineering, Kyoto University, Kyoto 615-8510, Japan
| | - Shinichi Enami
- W. M. Keck Laboratories, California Institute of Technology, Pasadena, California 91125, United States
| | - Michael R. Hoffmann
- W. M. Keck Laboratories, California Institute of Technology, Pasadena, California 91125, United States
| | - Agustín J. Colussi
- W. M. Keck Laboratories, California Institute of Technology, Pasadena, California 91125, United States
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228
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Davidovits P, Kolb CE, Williams LR, Jayne JT, Worsnop DR. Update 1 of: Mass Accommodation and Chemical Reactions at Gas−Liquid Interfaces. Chem Rev 2011; 111:PR76-109. [DOI: 10.1021/cr100360b] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Paul Davidovits
- Chemistry Department, 2609 Beacon Street, Boston College, Chestnut Hill, Massachusetts 02467, United States
| | - Charles E. Kolb
- Center for Aerosol and Cloud Chemistry, Aerodyne Research, Inc., 45 Manning Road, Billerica, Massachusetts 01821, United States
- This is a Chemical Reviews Perennial Review. The root paper of this title was published in Chem. Rev.2006, 106 (4), 1323−1354, DOI: 10.1021.cr040366k; Published (Web) March 16, 2006. Updates to the text appear in red type
| | - Leah R. Williams
- Center for Aerosol and Cloud Chemistry, Aerodyne Research, Inc., 45 Manning Road, Billerica, Massachusetts 01821, United States
- This is a Chemical Reviews Perennial Review. The root paper of this title was published in Chem. Rev.2006, 106 (4), 1323−1354, DOI: 10.1021.cr040366k; Published (Web) March 16, 2006. Updates to the text appear in red type
| | - John T. Jayne
- Center for Aerosol and Cloud Chemistry, Aerodyne Research, Inc., 45 Manning Road, Billerica, Massachusetts 01821, United States
- This is a Chemical Reviews Perennial Review. The root paper of this title was published in Chem. Rev.2006, 106 (4), 1323−1354, DOI: 10.1021.cr040366k; Published (Web) March 16, 2006. Updates to the text appear in red type
| | - Douglas R. Worsnop
- Center for Aerosol and Cloud Chemistry, Aerodyne Research, Inc., 45 Manning Road, Billerica, Massachusetts 01821, United States
- This is a Chemical Reviews Perennial Review. The root paper of this title was published in Chem. Rev.2006, 106 (4), 1323−1354, DOI: 10.1021.cr040366k; Published (Web) March 16, 2006. Updates to the text appear in red type
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229
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Shoji M, Kaniwa K, Hiranuma Y, Maselli O, Mafuné F. Solvation Structure of I− and Na+ on the Surface of NaI Aqueous Solution Studied by Photodetachment Spectroscopy in Combination with Mass Spectrometry. J Phys Chem A 2011; 115:2148-54. [DOI: 10.1021/jp109685d] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Makoto Shoji
- Department of Basic Science, Graduate School of Arts and Sciences, The University of Tokyo, Komaba, Meguro-ku, Tokyo 153-8902, Japan
| | - Keisuke Kaniwa
- Department of Basic Science, Graduate School of Arts and Sciences, The University of Tokyo, Komaba, Meguro-ku, Tokyo 153-8902, Japan
| | - Yojiro Hiranuma
- Department of Basic Science, Graduate School of Arts and Sciences, The University of Tokyo, Komaba, Meguro-ku, Tokyo 153-8902, Japan
| | - Olivia Maselli
- Department of Basic Science, Graduate School of Arts and Sciences, The University of Tokyo, Komaba, Meguro-ku, Tokyo 153-8902, Japan
| | - Fumitaka Mafuné
- Department of Basic Science, Graduate School of Arts and Sciences, The University of Tokyo, Komaba, Meguro-ku, Tokyo 153-8902, Japan
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230
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Saha R, Biswas S, Steele IM, Dey K, Mostafa G. A supramolecular spin crossover Fe(III) complex and its Cr(III) isomer: stabilization of water-chloride cluster within supramolecular host. Dalton Trans 2011; 40:3166-75. [PMID: 21340091 DOI: 10.1039/c0dt01256d] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The metal complexes, [M(Hdammthiol)(2)]Cl·3H(2)O [M = Cr(III) (1), Fe(III) (2)] [where H(2)dammthiol is the thiol form of the ligand, diacetylmonoxime morpholine N-thiohydrazone] were synthesized by metal template reactions of diacetylemonoxime with morpholine N-thiohydrazide in the presence of CrCl(3)·6H(2)O and FeCl(3)·6H(2)O. Both the complexes (1 and 2) were characterized by single crystal X-ray crystallography, spectroscopic (IR and UV-vis), Mössbauer and TGA analyses. The single crystal X-ray studies of both complexes show that the supramolecular hosts, constructed by the discrete mononuclear complexes, form supramolecular channels along the c-axis which are filled up by water-chloride clusters. In both complexes, the 1D water-chloride chain with chair-like architecture within the supramolecular hosts presents novelty. The magnetic measurement study of Fe(III) complex shows a spin crossover from S = 1/2 at 2.5 K to S = 5/2 at 300 K. At very low temperature, the presence of strong cooperative hydrogen bonding interactions stabilizes the S = 1/2 state.
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Affiliation(s)
- Rajat Saha
- Department of Physics, Jadavpur University, Jadavpur, Kolkata-700032, India
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231
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Feng RR, Guo Y, Lü R, Velarde L, Wang HF. Consistency in the Sum Frequency Generation Intensity and Phase Vibrational Spectra of the Air/Neat Water Interface. J Phys Chem A 2011; 115:6015-27. [DOI: 10.1021/jp110404h] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Ran-ran Feng
- Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, the Chinese Academy of Sciences, Beijing 100190, China
| | - Yuan Guo
- Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, the Chinese Academy of Sciences, Beijing 100190, China
| | - Rong Lü
- Department of Chemistry, Renmin University of China, Beijing 100872, China
| | - Luis Velarde
- William R. Wiley Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, P.O. Box 999, Richland, Washington 99352, United States
| | - Hong-fei Wang
- William R. Wiley Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, P.O. Box 999, Richland, Washington 99352, United States
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232
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Richards NK, Wingen LM, Callahan KM, Nishino N, Kleinman MT, Tobias DJ, Finlayson-Pitts BJ. Nitrate Ion Photolysis in Thin Water Films in the Presence of Bromide Ions. J Phys Chem A 2011; 115:5810-21. [DOI: 10.1021/jp109560j] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Nicole K. Richards
- Department of Chemistry, University of California, Irvine, California 92697-2025, United States
| | - Lisa M. Wingen
- Department of Chemistry, University of California, Irvine, California 92697-2025, United States
| | - Karen M. Callahan
- Department of Chemistry, University of California, Irvine, California 92697-2025, United States
| | - Noriko Nishino
- Department of Chemistry, University of California, Irvine, California 92697-2025, United States
| | - Michael T. Kleinman
- Department of Medicine, University of California, Irvine, California 92697-1825, United States
| | - Douglas J. Tobias
- Department of Chemistry, University of California, Irvine, California 92697-2025, United States
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233
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Ciuraru R, Gosselin S, Visez N, Petitprez D. Heterogeneous reactivity of chlorine atoms with sodium chloride and synthetic sea salt particles. Phys Chem Chem Phys 2011; 13:19460-70. [DOI: 10.1039/c1cp22170a] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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234
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235
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Feng Y, Cheng M, Kong XY, Xu HG, Zheng WJ. Microscopic solvation of NaBO2 in water: anion photoelectron spectroscopy and ab initio calculations. Phys Chem Chem Phys 2011; 13:15865-72. [PMID: 21814667 DOI: 10.1039/c1cp20831d] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Affiliation(s)
- Yuan Feng
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory of Molecular Reaction Dynamics, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
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236
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Callahan KM, Casillas-Ituarte NN, Xu M, Roeselová M, Allen HC, Tobias DJ. Effect of magnesium cation on the interfacial properties of aqueous salt solutions. J Phys Chem A 2010; 114:8359-68. [PMID: 20701343 DOI: 10.1021/jp103485t] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Sodium chloride solutions have been used extensively as a model of seawater in both theoretical and experimental studies of the chemistry of sea salt aerosol. Many groups have found that chloride anions are present at the air-solution interface. This observation has been important for the development of a mechanism for the heterogeneous production of molecular chlorine from chloride in sea salt aerosol. However, while sodium chloride is a major constituent of seawater, it is by no means the only salt present. Seawater contains one Mg(2+) for every eight Na(+). Mg(2+) is naturally occurring in ocean waters from mineral deposits in the Earth's crust and biological sources. Mg(2+) forms a hexahydrate structure, rather than contact ion pairs with chloride anion, and this impacts the ordering of water in solution. In this study, we use molecular dynamics simulations, ab initio calculations, and vibrational sum frequency generation (SFG) spectroscopy to explore the effect of the Mg(2+) cation and its tightly bound solvation shell on the surface propensity of chloride, ion-ion interactions, and water structure of the air-solution interface of concentrated chloride salt solutions. In addition, we provide molecular level details that may be relevant to the heterogeneous reactions of chloride in deliquesced sea salt aerosols. In particular, we show that the presence of the divalent Mg(2+) cation does not modify the surface propensity of chloride compared to Na(+) and hence, its availability to interfacial reaction, although some differences in the behavior of chloride may occur due to specific ion interactions. In this work, we also discuss the SFG free OH band at the surface of salt solutions and conclude that it is often not straightforward to interpret.
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Affiliation(s)
- Karen M Callahan
- AirUCI Environmental Molecular Science Institute and Department of Chemistry, University of California, Irvine, California 92697, USA
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237
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Chen X, Flores SC, Lim SM, Zhang Y, Yang T, Kherb J, Cremer PS. Specific anion effects on water structure adjacent to protein monolayers. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:16447-16454. [PMID: 20560589 DOI: 10.1021/la1015862] [Citation(s) in RCA: 94] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Vibrational sum frequency spectroscopy (VSFS) was used to explore specific ion effects on interfacial water structure adjacent to a bovine serum albumin (BSA) monolayer adsorbed at the air/water interface. The subphase conditions were varied by the use of six different sodium salts and four different pH values. At pH 2 and 3, the protein layer was positively charged and it was found that the most chaotropic anions caused the greatest attenuation of water structure. The order of the salts followed an inverse Hofmeister series. On the other hand, when the protein layer was near its isoelectric point (pH 5), the most chaotropic anions caused the greatest increase in water structure, although the effect was weak. In this case, a direct Hofmeister series was obeyed. Finally, virtually no effect was observed when the protein layer was negatively charged with a subphase pH of 9. For comparison, similar experiments were run with positively charged, negatively charged, and zwitterionic surfactant monolayers. These experiments gave rise to nearly the identical results as the protein monolayer which suggested that specific anion effects are dominated by the charge state of the interfacial layer rather than its detailed chemical structure. In a final set of experiments, salt effects were examined with a monolayer made from an elastin-like polypeptide (ELP). The peptide consisted of 120 pentameric repeats of the sequence Val-Pro-Gly-Val-Gly. Data from this net neutral biopolymer followed a very weak, but direct Hofmeister series. This suggested that direct anion binding to the amide groups in the backbone of a polypeptide is quite weak in agreement with the BSA data. The results from the variously charged protein, surfactant, and polymer monolayers were compared with a modified Gouy-Chapman-Stern model. The agreement with this simple model was quite good.
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Affiliation(s)
- Xin Chen
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, USA
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238
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Sun X, Wick CD, Dang LX. Computational Study of Ion Distributions at the Air/Liquid Methanol Interface. J Phys Chem A 2010; 115:5767-73. [DOI: 10.1021/jp107563e] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Xiuquan Sun
- Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Collin D. Wick
- Louisiana Tech University, Ruston, Louisiana 71270, United States
| | - Liem X. Dang
- Pacific Northwest National Laboratory, Richland, Washington 99352, United States
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239
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Martín-García B, Velázquez MM, Pérez-Hernández JA, Hernández-Toro J. Langmuir and Langmuir-Blodgett films of a maleic anhydride derivative: effect of subphase divalent cations. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:14556-14562. [PMID: 20795708 DOI: 10.1021/la101736e] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
We report the study of the equilibrium and dynamic properties of Langmuir monolayers of poly(styrene-co-maleic anhydride) partial 2-buthoxyethyl ester cumene terminated polymer and the effect of the Mg(NO(3))(2) addition in the water subphase on the film properties. Results show that the polymer monolayer becomes more expanded when the electrolyte concentration in the subphase increases. Dense polymer films aggregate at the interface. The aggregates are transferred onto silicon wafers using the Langmuir-Blodgett methodology and the morphology is observed by AFM. The structure of aggregates depends on the subphase composition of the Langmuir film transferred onto the silicon wafer.
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Affiliation(s)
- B Martín-García
- Departamento de Química Física, Facultad de Ciencias Químicas, Universidad de Salamanca, E-37008-Salamanca, Spain
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240
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Abstract
Atmospheric aerosol particles play pivotal roles in climate and air quality. Just as chemically reduced gases experience oxidation in the atmosphere, it is now apparent that solid and liquid atmospheric particulates are also subject to similar oxidative processes. The most reactive atmospheric gas-phase radicals, in particular the hydroxyl radical, readily promote such chemistry through surficial interactions. This Review looks at progress made in this field, discussing the radical-initiated heterogeneous oxidation of organic and inorganic constituents of atmospheric aerosols. We focus on the kinetics and reaction mechanisms of such processes as well as how they can affect the physico-chemical properties of particles, such as their composition, size, density and hygroscopicity. Potential impacts on the atmosphere include the release of chemically reactive gases such as halogens, aldehydes and organic acids, reactive loss of particle-borne molecular tracer and toxic species, and enhanced hygroscopic properties of aerosols that may improve their ability to form cloud droplets.
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241
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Schlicht F, Entfellner M, Boesl U. Anion ZEKE-Spectroscopy of the Weakly Bound Iodine Water Complex. J Phys Chem A 2010; 114:11125-32. [DOI: 10.1021/jp102508f] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Franz Schlicht
- Technische Universität München, Physical Chemistry, 85748 Garching, Germany
| | | | - Ulrich Boesl
- Technische Universität München, Physical Chemistry, 85748 Garching, Germany
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242
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Feng H, Zhou J, Lu X, Fichthorn KA. Communication: Molecular dynamics simulations of the interfacial structure of alkali metal fluoride solutions. J Chem Phys 2010; 133:061103. [DOI: 10.1063/1.3478520] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
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243
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Ahadi E, Konermann L. Surface Charge of Electrosprayed Water Nanodroplets: A Molecular Dynamics Study. J Am Chem Soc 2010; 132:11270-7. [DOI: 10.1021/ja1041989] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Elias Ahadi
- Department of Chemistry, The University of Western Ontario, London, Ontario N6A 5B7, Canada
| | - Lars Konermann
- Department of Chemistry, The University of Western Ontario, London, Ontario N6A 5B7, Canada
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244
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Callahan KM, Casillas-Ituarte NN, Roeselová M, Allen HC, Tobias DJ. Solvation of magnesium dication: molecular dynamics simulation and vibrational spectroscopic study of magnesium chloride in aqueous solutions. J Phys Chem A 2010; 114:5141-8. [PMID: 20201546 DOI: 10.1021/jp909132a] [Citation(s) in RCA: 102] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Magnesium dication plays many significant roles in biochemistry. While it is available to the environment from both ocean waters and mineral salts on land, its roles in environmental and atmospheric chemistry are still relatively unknown. Several pieces of experimental evidence suggest that contact ion pairing may not exist at ambient conditions in solutions of magnesium chloride up to saturation concentrations. This is not typical of most ions. There has been disagreement in the molecular dynamics literature concerning the existence of ion pairing in magnesium chloride solutions. Using a force field developed during this study, we show that contact ion pairing is not energetically favorable. Additionally, we present a concentration-dependent Raman spectroscopic study of the Mg-O(water) hexaaquo stretch that clearly supports the absence of ion pairing in MgCl(2) solutions, although a transition occurring in the spectrum between 0.06x and 0.09x suggests a change in solution structure. Finally, we compare experimental and calculated observables to validate our force field as well as two other commonly used magnesium force fields, and in the process show that ion pairing of magnesium clearly is not observed at higher concentrations in aqueous solutions of magnesium chloride, independent of the choice of magnesium force field, although some force fields give better agreement to experimental results than others.
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Affiliation(s)
- Karen M Callahan
- Environmental Molecular Science Institute and Department of Chemistry, University of California, Irvine, California 92697, USA
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245
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Bunkin NF, Ninham BW, Babenko VA, Suyazov NV, Sychev AA. Role of dissolved gas in optical breakdown of water: differences between effects due to helium and other gases. J Phys Chem B 2010; 114:7743-52. [PMID: 20496876 DOI: 10.1021/jp101657f] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
It is shown that water contains defects in the form of heterogeneous optical breakdown centers. Long-living complexes composed of gas and liquid molecules may serve as nuclei for such centers. A new technique for removing dissolved gas from water is developed. It is based on a "helium washing" routine. The structure of helium-washed water is very different from that of water containing dissolved atmospheric gas. It is able to withstand higher optical intensities and temperatures of superheating compared with the nonprocessed ones. The characteristics of plasma spark and values of the breakdown thresholds for processed and nonprocessed samples are given.
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Affiliation(s)
- N F Bunkin
- A.M. Prokhorov General Physics Institute, Russian Academy of Sciences, ul. Vavilova, 38, 119991, Moscow, Russia.
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246
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Abstract
The study of the interactions of salts and osmolytes with macromolecules in aqueous solution originated with experiments concerning protein precipitation more than 100 years ago. Today, these solutes are known to display recurring behavior for myriad biological and chemical processes. Such behavior depends both on the nature and concentration of the species in solution. Despite the generality of these effects, our understanding of the molecular-level details of ion and osmolyte specificity is still quite limited. Here, we review recent studies of the interactions between anions and urea with model macromolecular systems. A mechanism for specific ion effects is elucidated for aqueous systems containing charged and uncharged polymers, polypeptides, and proteins. The results clearly show that the effects of the anions are local and involve direct interactions with macromolecules and their first hydration shell. Also, a hydrogen-bonding mechanism is tested for the urea denaturation of proteins with some of these same systems. In that case, direct hydrogen bonding can be largely discounted as the key mechanism for urea stabilization of uncollapsed and/or unfolded structures.
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Affiliation(s)
- Yanjie Zhang
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, USA
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249
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Keasler SJ, Kim H, Chen B. Ion-Induced Nucleation: The Importance of Ionic Polarizability. J Phys Chem A 2010; 114:4595-600. [DOI: 10.1021/jp910727e] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
| | - Hyunmi Kim
- Louisiana State University, Baton Rouge, Louisiana 70803
| | - Bin Chen
- Louisiana State University, Baton Rouge, Louisiana 70803
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250
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Affiliation(s)
- M. N. Tamashiro
- Instituto de Física “Gleb Wataghin”, Universidade Estadual de Campinas, Caixa Postal 6165, 13083-970, Campinas, São Paulo, Brazil
| | - M. A. Constantino
- Instituto de Física “Gleb Wataghin”, Universidade Estadual de Campinas, Caixa Postal 6165, 13083-970, Campinas, São Paulo, Brazil
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