201
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Zhang FQ, Guan W, Zhang YT, Xu MT, Li J, Su ZM. On the Origin of the Inverted Stability Order of the Reverse-Keggin [(MnO4)(CH3)12Sb12O24]6−: A DFT Study of α, β, γ, δ, and ε Isomers. Inorg Chem 2010; 49:5472-81. [DOI: 10.1021/ic100343t] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Fu-Qiang Zhang
- Department of Chemistry, Shangqiu Normal University, Shangqiu 476000, People's Republic of China
| | - Wei Guan
- Institute of Functional Material Chemistry, Department of Chemistry, Northeast Normal University, Changchun 130024, People's Republic of China
| | - Yin-Tang Zhang
- Department of Chemistry, Shangqiu Normal University, Shangqiu 476000, People's Republic of China
| | - Mao-Tian Xu
- Department of Chemistry, Shangqiu Normal University, Shangqiu 476000, People's Republic of China
| | - Jian Li
- Department of Chemistry, Shangqiu Normal University, Shangqiu 476000, People's Republic of China
| | - Zhong-Min Su
- Institute of Functional Material Chemistry, Department of Chemistry, Northeast Normal University, Changchun 130024, People's Republic of China
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202
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Wehr JB, Blamey FPC, Hanna JV, Kopittke PM, Kerven GL, Menzies NW. Hydrolysis and speciation of Al bound to pectin and plant cell wall material and its reaction with the dye chrome azurol S. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2010; 58:5553-5560. [PMID: 20380374 DOI: 10.1021/jf100201x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Hydrolysis of aluminum (Al) in solution increases at pH >or= 4 and with an Al concentration. Pectin, an important anionic polysaccharide of plant cell walls, adsorbs Al, but this phenomenon is poorly understood. This study showed that Al(3+) hydrolysis results in binding of Al to pectin in excess of the stoichiometric equivalent, leading to oversaturation of the pectin with Al. However, the degree of pectin methyl-esterification did not affect the extent of Al hydrolysis. Binding of Al to purified cell wall material also resulted in Al hydrolysis in a pH- and soluble Al concentration-dependent manner, but the source of cell wall material had no effect at fixed pH. Staining of Al-treated pectin and cell wall material from wheat ( Triticum aestivum L.) and sunflower ( Helianthus annuus L.) with the Al-specific dye, chrome azurol S (CAS), resulted in the formation of a purple color, with the intensity related to the extent of Al hydrolysis.
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Affiliation(s)
- J Bernhard Wehr
- School of Land, Crop and Food Sciences, The University of Queensland, St. Lucia, Queensland, Australia.
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203
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Saukkoriipi J, Laasonen K. Theoretical Study of the Hydrolysis of Pentameric Aluminum Complexes. J Chem Theory Comput 2010. [DOI: 10.1021/ct900670a] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jaakko Saukkoriipi
- Department of Chemistry, University of Oulu, P.O. Box 3000, Oulu FI-90014, Finland
| | - Kari Laasonen
- Department of Chemistry, University of Oulu, P.O. Box 3000, Oulu FI-90014, Finland
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204
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Villa EM, Ohlin CA, Casey WH. Oxygen-Isotope Exchange Rates for Three Isostructural Polyoxometalate Ions. J Am Chem Soc 2010; 132:5264-72. [DOI: 10.1021/ja100490n] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- Eric M. Villa
- Departments of Chemistry and Geology, University of California, Davis, California 95616
| | - C. André Ohlin
- Departments of Chemistry and Geology, University of California, Davis, California 95616
| | - William H. Casey
- Departments of Chemistry and Geology, University of California, Davis, California 95616
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205
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Lin YF, Lee DJ. Electrospray Mass Spectrometry Studies of Purified Aluminum Tridecamer in a 50:50 Water/Acetonitrile Mixture. J Phys Chem A 2010; 114:3503-9. [DOI: 10.1021/jp912101g] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Ya-Fan Lin
- Department of Chemical Engineering, National Taiwan University, Taipei, Taiwan 10617
| | - Duu-Jong Lee
- Department of Chemical Engineering, National Taiwan University, Taipei, Taiwan 10617
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206
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Liu J, Zhao F. Structural change and mineralogical transformation mechanism of aluminum hydroxide gels from forced hydrolysis Al(III) solutions containing AlO4Al12(OH)24(H2O)12 7+ polyoxycation during aging. ACTA ACUST UNITED AC 2010. [DOI: 10.1007/s11631-010-0107-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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207
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Ohlin CA, Villa EM, Rustad JR, Casey WH. Dissolution of insulating oxide materials at the molecular scale. NATURE MATERIALS 2010; 9:11-19. [PMID: 20019664 DOI: 10.1038/nmat2585] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Our understanding of mineral and glass dissolution has advanced from simple thermodynamic treatments to models that emphasize adsorbate structures. This evolution was driven by the idea that the best understanding is built at the molecular level. Now, it is clear that the molecular questions cannot be answered uniquely with dissolution experiments. At the surface it is unclear which functional groups are present, how they are arranged, and how they interact with each other and with solutes as the key bonds are activated. An alternative approach has developed whereby reactions are studied with nanometre-sized aqueous oxide ions that serve as models for the more complicated oxide interface. For these ions, establishing the structure is not a research problem in itself, and bond ruptures and dissociations can be followed with much confidence. We review the field from bulk-dissolution kinetics to the new isotope-exchange experiments in large oxide ions.
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Affiliation(s)
- C André Ohlin
- Department of Chemistry, University of California, Davis, California 95616, USA
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208
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Rustad JR. Elementary Reactions in Polynuclear Ions and Aqueous–Mineral Interfaces: A New Geology. ADVANCES IN INORGANIC CHEMISTRY 2010. [DOI: 10.1016/s0898-8838(10)62010-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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209
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Yao K, Huang D, Xu B, Wang N, Wang Y, Bi S. A sensitive electrochemical approach for monitoring the effects of nano-Al2O3on LDH activity by differential pulse voltammetry. Analyst 2010; 135:116-20. [DOI: 10.1039/b910557c] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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210
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Qian Z, Feng H, Jin X, Yang W, Wang Y, Bi S. Density functional investigation of the water exchange reaction on the gibbsite surface. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2009; 43:9281-9286. [PMID: 20000521 DOI: 10.1021/es901583m] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The water exchange reactions on the gibbsite surface have been investigated by density functional calculations (B3LYP/6-31G(d) level) combining the supermolecular model and PCM model in this paper, and the water exchange rate constants on the gibbsite surface have also been predicted. In the proposed reaction pathways, the clusters Al6(OH)18(H2O)6(0) and Al6(OH)12(H2O)12(6+) are used as the models of gibbsite surface and protonated gibbsite surface respectively to examine the effect of protonation of gibbsite surface on the water exchange rate constants. The activation energy barriers DeltaE(s) not equal to (aq) for Al6(OH)18(H2O)6(0) and Al6(OH)12(H2O)12(6+) are 28.6 and 27.2 kJ*mol-1, respectively. The reaction energies DeltaE(s) (aq) for Al6(OH)18(H2O)6(0) and Al6(OH)12(H2O)12(6+) are 2.9 and 14.4 kJ mol-1, respectively, indicating that hexacoordinate aluminum in the gibbsite surface is more stable. The log k(TST) for Al6(OH)18(H2O)6(0) and Al6(OH)12(H2O)12(6+) are 6.5 and 7.5 respectively, and the log k(ex) calculated by the given transmission coefficient for Al6(OH)18-(H2O)6(0) and Al6(OH)12(H2O)12(6+) are 2.4 and 3.4 respectively, indicating that the protonation of gibbsite surface promotes the water exchange reaction of gibbsite surface and accelerates the dissolution rate of gibbsite. The relationship between the calculated free energy and experimental rate constants was explored, and according to this relationship, the log k(ex) for Al6(OH)18(H2O)6(0) and Al6(OH)12(H2O)12(6+) are 2.5 and 3.1 respectively, close to the corresponding values calculated by the given transmission coefficient. The water exchange rate constant of gibbsite surface is close to those of K-MAl(12)(M = Al, Ga, and Ge) polyoxocations, but deviates from that of Al(H2O)6(3+), implying that the same reactions with similar structure have similar water exchange rate constants.
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Affiliation(s)
- Zhaosheng Qian
- School of Chemistry and Chemical Engineering, State Key Laboratory of Coordination Chemistry of China and Key Laboratory of MOE for Life Science, Nanjing University, Nanjing 210093, China
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211
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212
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Geletii YV, Besson C, Hou Y, Yin Q, Musaev DG, Quiñonero D, Cao R, Hardcastle KI, Proust A, Kögerler P, Hill CL. Structural, Physicochemical, and Reactivity Properties of an All-Inorganic, Highly Active Tetraruthenium Homogeneous Catalyst for Water Oxidation. J Am Chem Soc 2009; 131:17360-70. [DOI: 10.1021/ja907277b] [Citation(s) in RCA: 153] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Yurii V. Geletii
- Department of Chemistry, Emory University, Atlanta, Georgia 30322, Institut Parisien de Chimie Moléculaire, UMR CNRS 7201, UPMC Univ Paris 06, 4 Place Jussieu, Case 42, 75252, Paris Cedex 05, France, Cherry L. Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322, Institut für Anorganische Chemie, RWTH Aachen University, D-52074 Aachen, Germany, and Institut Universitaire de France, 103, Boulevard Saint-Michel 75005 Paris, France
| | - Claire Besson
- Department of Chemistry, Emory University, Atlanta, Georgia 30322, Institut Parisien de Chimie Moléculaire, UMR CNRS 7201, UPMC Univ Paris 06, 4 Place Jussieu, Case 42, 75252, Paris Cedex 05, France, Cherry L. Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322, Institut für Anorganische Chemie, RWTH Aachen University, D-52074 Aachen, Germany, and Institut Universitaire de France, 103, Boulevard Saint-Michel 75005 Paris, France
| | - Yu Hou
- Department of Chemistry, Emory University, Atlanta, Georgia 30322, Institut Parisien de Chimie Moléculaire, UMR CNRS 7201, UPMC Univ Paris 06, 4 Place Jussieu, Case 42, 75252, Paris Cedex 05, France, Cherry L. Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322, Institut für Anorganische Chemie, RWTH Aachen University, D-52074 Aachen, Germany, and Institut Universitaire de France, 103, Boulevard Saint-Michel 75005 Paris, France
| | - Qiushi Yin
- Department of Chemistry, Emory University, Atlanta, Georgia 30322, Institut Parisien de Chimie Moléculaire, UMR CNRS 7201, UPMC Univ Paris 06, 4 Place Jussieu, Case 42, 75252, Paris Cedex 05, France, Cherry L. Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322, Institut für Anorganische Chemie, RWTH Aachen University, D-52074 Aachen, Germany, and Institut Universitaire de France, 103, Boulevard Saint-Michel 75005 Paris, France
| | - Djamaladdin G. Musaev
- Department of Chemistry, Emory University, Atlanta, Georgia 30322, Institut Parisien de Chimie Moléculaire, UMR CNRS 7201, UPMC Univ Paris 06, 4 Place Jussieu, Case 42, 75252, Paris Cedex 05, France, Cherry L. Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322, Institut für Anorganische Chemie, RWTH Aachen University, D-52074 Aachen, Germany, and Institut Universitaire de France, 103, Boulevard Saint-Michel 75005 Paris, France
| | - David Quiñonero
- Department of Chemistry, Emory University, Atlanta, Georgia 30322, Institut Parisien de Chimie Moléculaire, UMR CNRS 7201, UPMC Univ Paris 06, 4 Place Jussieu, Case 42, 75252, Paris Cedex 05, France, Cherry L. Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322, Institut für Anorganische Chemie, RWTH Aachen University, D-52074 Aachen, Germany, and Institut Universitaire de France, 103, Boulevard Saint-Michel 75005 Paris, France
| | - Rui Cao
- Department of Chemistry, Emory University, Atlanta, Georgia 30322, Institut Parisien de Chimie Moléculaire, UMR CNRS 7201, UPMC Univ Paris 06, 4 Place Jussieu, Case 42, 75252, Paris Cedex 05, France, Cherry L. Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322, Institut für Anorganische Chemie, RWTH Aachen University, D-52074 Aachen, Germany, and Institut Universitaire de France, 103, Boulevard Saint-Michel 75005 Paris, France
| | - Kenneth I. Hardcastle
- Department of Chemistry, Emory University, Atlanta, Georgia 30322, Institut Parisien de Chimie Moléculaire, UMR CNRS 7201, UPMC Univ Paris 06, 4 Place Jussieu, Case 42, 75252, Paris Cedex 05, France, Cherry L. Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322, Institut für Anorganische Chemie, RWTH Aachen University, D-52074 Aachen, Germany, and Institut Universitaire de France, 103, Boulevard Saint-Michel 75005 Paris, France
| | - Anna Proust
- Department of Chemistry, Emory University, Atlanta, Georgia 30322, Institut Parisien de Chimie Moléculaire, UMR CNRS 7201, UPMC Univ Paris 06, 4 Place Jussieu, Case 42, 75252, Paris Cedex 05, France, Cherry L. Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322, Institut für Anorganische Chemie, RWTH Aachen University, D-52074 Aachen, Germany, and Institut Universitaire de France, 103, Boulevard Saint-Michel 75005 Paris, France
| | - Paul Kögerler
- Department of Chemistry, Emory University, Atlanta, Georgia 30322, Institut Parisien de Chimie Moléculaire, UMR CNRS 7201, UPMC Univ Paris 06, 4 Place Jussieu, Case 42, 75252, Paris Cedex 05, France, Cherry L. Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322, Institut für Anorganische Chemie, RWTH Aachen University, D-52074 Aachen, Germany, and Institut Universitaire de France, 103, Boulevard Saint-Michel 75005 Paris, France
| | - Craig L. Hill
- Department of Chemistry, Emory University, Atlanta, Georgia 30322, Institut Parisien de Chimie Moléculaire, UMR CNRS 7201, UPMC Univ Paris 06, 4 Place Jussieu, Case 42, 75252, Paris Cedex 05, France, Cherry L. Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322, Institut für Anorganische Chemie, RWTH Aachen University, D-52074 Aachen, Germany, and Institut Universitaire de France, 103, Boulevard Saint-Michel 75005 Paris, France
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213
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Rustad JR, Dixon DA. Prediction of Iron-Isotope Fractionation Between Hematite (α-Fe2O3) and Ferric and Ferrous Iron in Aqueous Solution from Density Functional Theory. J Phys Chem A 2009; 113:12249-55. [DOI: 10.1021/jp9065373] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- James R. Rustad
- Department of Geology, University of California, Davis, One Shields Avenue, Davis, California 95616, and Department of Chemistry, University of Alabama, Tuscaloosa, Alabama 35487
| | - David A. Dixon
- Department of Geology, University of California, Davis, One Shields Avenue, Davis, California 95616, and Department of Chemistry, University of Alabama, Tuscaloosa, Alabama 35487
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214
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Lin JL, Huang C, Chin CJM, Pan JR. The origin of Al(OH)(3)-rich and Al(13)-aggregate flocs composition in PACl coagulation. WATER RESEARCH 2009; 43:4285-4295. [PMID: 19592064 DOI: 10.1016/j.watres.2009.06.023] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2009] [Revised: 06/06/2009] [Accepted: 06/10/2009] [Indexed: 05/28/2023]
Abstract
The composition of hydrolyzed Al species is essential for the understanding of coagulation with Al-based coagulants. Surface characteristics of flocs formed by coagulation with two distinct polyaluminum chloride (PACl) coagulants were identified. One commercial coagulant (PACl-C) with voluminous monomeric Al and colloidal Al(OH)(3) and a custom-made PACl (PACl-Al(13)) containing high Al(13) content were applied to destabilize kaolin particles. The flocs formed by PACl-C and PACl-Al(13) at neutral and alkaline pH ranges, respectively, were observed by FE-SEM and HR-TEM. In addition, the Al composition of these flocs was characterized by XPS and HR-XRD, and the imaging of Al(OH)(3) precipitates and Al(13) aggregates were conducted by SEM as well as tapping mode AFM in liquid system. The observations of flocs indicate that the morphology of Al(OH)(3)-rich flocs are fluffy and porous around the edge of flocs, while the Al(13)-aggregate flocs have a glossy contour and irregular structure. Both Al(OH)(3)-rich and Al(13)-aggregate flocs do not possess well-formed crystalline structure except for the Al(13)-like crystal exists in the Al(13)-aggregate flocs. Among Al(OH)(3) precipitates, colloidal Al(OH)(3) is micro-scale in size, while amorphous Al(OH)(3) is nano-scale. During the formation of Al(13) aggregates, some coiled and clustered Al(13) aggregates with smoother surface were observed. The XPS study on floc surface showed that tetrahedral (Al(IV)) /octahedral (Al(VI)) Al ratio on the surfaces of PACl-C and PACl-Al(13) flocs is 1:1.6 and 1:9.9, respectively. Of the in situ formed Al(13), almost half of Al-hydroxide precipitates on the surface of Al(OH)(3)-rich flocs possess the Al(IV) center. It also found that the irregularly aggregated Al(13) with a similar Al(13) crystalline structure subsists on the surface of Al(13)-aggregate flocs.
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Affiliation(s)
- Jr-Lin Lin
- Institute of Environmental Engineering, National Chiao-Tung University, Hsinchu Taiwan
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215
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Villa EM, Ohlin CA, Rustad JR, Casey WH. Isotope-Exchange Dynamics in Isostructural Decametalates with Profound Differences in Reactivity. J Am Chem Soc 2009; 131:16488-92. [DOI: 10.1021/ja905166c] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Eric M. Villa
- Departments of Chemistry and Geology, University of California, Davis, California 95616
| | - C. André Ohlin
- Departments of Chemistry and Geology, University of California, Davis, California 95616
| | - James R. Rustad
- Departments of Chemistry and Geology, University of California, Davis, California 95616
| | - William H. Casey
- Departments of Chemistry and Geology, University of California, Davis, California 95616
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216
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Stewart TA, Trudell DE, Alam TM, Ohlin CA, Lawler C, Casey WH, Jett S, Nyman M. Enhanced water purification: a single atom makes a difference. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2009; 43:5416-5422. [PMID: 19708375 DOI: 10.1021/es803683t] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The aluminum Keggin polycation (Al13) has been identified as an effective specie for neutralization and coagulation of anionic contaminants in water. In this study, we compare efficacy of the aluminum Keggin-ion to the analogues containing a single Ga-atom or single Ge-atom (GaAl12 and GeAl12, respectively) substituted into the center of the polycation in water-treatment studies. We investigated removal of bacteriophage (model viruses), Cryptosporidium, dissolved organic carbon (DOC), and turbidity. In every study, the order of contaminant removal efficacy trends GaAl12 > Al13 > GeAl12. By ESI MS (electrospray ionization mass spectrometry), we noted the GaAl12 deprotonates least of the three aluminum polycations, and thus probably carries the highest charge, and also optimal contaminant-neutralization ability. The ESI MS studies of the aluminum polycation solutions, as well as solid-state characterization of their resulting precipitates both reveal some conversion of Al13 to larger polycations, Al30 for instance. The GaAl12 does not show any evidence for this alteration that is responsible for poor shelf life of commercial prehydrolyzed aluminum coagulants such as polyaluminum chloride. Based on these studies, we conclude that substitution of a single Ga-atom in the center of the aluminum Keggin polycation produces an optimal water-treatment product due to enhanced shelf life and efficacy in neutralization of anionic contaminants.
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Affiliation(s)
- Tom A Stewart
- Sandia National Laboratories, P.O. Box 5800 MS-0750, Albuquerque, New Mexico 87185, USA
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217
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A systematic study for the characterization of a novel coagulant (polyaluminium silicate chloride). Colloids Surf A Physicochem Eng Asp 2009. [DOI: 10.1016/j.colsurfa.2009.03.054] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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218
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Casey W, Rustad J, Spiccia L. Minerals as Molecules-Use of Aqueous Oxide and Hydroxide Clusters to Understand Geochemical Reactions. Chemistry 2009; 15:4496-515. [DOI: 10.1002/chem.200802636] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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219
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Li H, Zhang L, Dai H, He H. Facile Synthesis and Unique Physicochemical Properties of Three-Dimensionally Ordered Macroporous Magnesium Oxide, Gamma-Alumina, and Ceria−Zirconia Solid Solutions with Crystalline Mesoporous Walls. Inorg Chem 2009; 48:4421-34. [DOI: 10.1021/ic900132k] [Citation(s) in RCA: 195] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Huining Li
- Laboratory of Catalysis Chemistry and Nanoscience, Department of Chemistry and Chemical Engineering, College of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100124, China
| | - Lei Zhang
- Laboratory of Catalysis Chemistry and Nanoscience, Department of Chemistry and Chemical Engineering, College of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100124, China
| | - Hongxing Dai
- Laboratory of Catalysis Chemistry and Nanoscience, Department of Chemistry and Chemical Engineering, College of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100124, China
| | - Hong He
- Laboratory of Catalysis Chemistry and Nanoscience, Department of Chemistry and Chemical Engineering, College of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100124, China
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220
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Qian Z, Feng H, He L, Yang W, Bi S. Assessment of the Accuracy of Theoretical Methods for Calculating 27Al Nuclear Magnetic Resonance Shielding Tensors of Aquated Aluminum Species. J Phys Chem A 2009; 113:5138-43. [DOI: 10.1021/jp810632f] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Zhaosheng Qian
- School of Chemistry and Chemical Engineering, State Key Laboratory of Coordination Chemistry of China & Key Laboratory of MOE for Life Science, Nanjing University, Nanjing 210093, China
| | - Hui Feng
- School of Chemistry and Chemical Engineering, State Key Laboratory of Coordination Chemistry of China & Key Laboratory of MOE for Life Science, Nanjing University, Nanjing 210093, China
| | - Lina He
- School of Chemistry and Chemical Engineering, State Key Laboratory of Coordination Chemistry of China & Key Laboratory of MOE for Life Science, Nanjing University, Nanjing 210093, China
| | - Wenjing Yang
- School of Chemistry and Chemical Engineering, State Key Laboratory of Coordination Chemistry of China & Key Laboratory of MOE for Life Science, Nanjing University, Nanjing 210093, China
| | - Shuping Bi
- School of Chemistry and Chemical Engineering, State Key Laboratory of Coordination Chemistry of China & Key Laboratory of MOE for Life Science, Nanjing University, Nanjing 210093, China
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221
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Fournier A, Shafran K, Perry C. A multi-technique study of the effect of aqueous aluminium speciation on hydrolytic gelation of aluminium (oxy)hydroxide. J Colloid Interface Sci 2009; 332:122-9. [DOI: 10.1016/j.jcis.2008.12.042] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2008] [Revised: 12/12/2008] [Accepted: 12/15/2008] [Indexed: 11/25/2022]
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222
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Zhao H, Liu H, Qu J. Effect of pH on the aluminum salts hydrolysis during coagulation process: Formation and decomposition of polymeric aluminum species. J Colloid Interface Sci 2009; 330:105-12. [DOI: 10.1016/j.jcis.2008.10.020] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2008] [Revised: 10/08/2008] [Accepted: 10/10/2008] [Indexed: 11/27/2022]
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223
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Characterization of arsenate adsorption on amorphous Al gels with Keggin structure by Fourier transformed infrared spectroscopy and MAS 27Al NMR. ACTA ACUST UNITED AC 2009. [DOI: 10.1007/s11631-009-0061-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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224
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Yang W, Qian Z, Miao Q, Wang Y, Bi S. Density functional theory study of the aluminium(iii) hydrolysis in aqueous solution. Phys Chem Chem Phys 2009; 11:2396-401. [DOI: 10.1039/b819484j] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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225
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Qian Z, Feng H, Yang W, Zhang Z, Wang Y, Bi S. Theoretical investigation of dehydration of aquated Al(OH)2+ species in aqueous solution. Dalton Trans 2009:1554-8. [DOI: 10.1039/b816081c] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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226
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Qian Z, Feng H, Zhang Z, Yang W, Jin J, Miao Q, He L, Bi S. Theoretical investigation on the dimerization of the deprotonated aquo ion of Al(iii) in water. Dalton Trans 2009:521-9. [DOI: 10.1039/b812485j] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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227
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Zhao C, Zhang J, Luan Z, Peng X, Ren X. Preparation of high concentration polyaluminum chloride with high content of Alb or Alc. J Environ Sci (China) 2009; 21:1342-1346. [PMID: 19999987 DOI: 10.1016/s1001-0742(08)62424-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
A novel membrane distillation concentration method was used to prepare high concentration polyaluminum chloride (PACl) with high content of Alb or Alc. 2.52 mol/L PACl1 with 88% Alb and 2.38 mol/L PACl2 with 61% Alc were successfully prepared. Three coagulants, AlCl3, PACl1 and PACl2 were investigated on their hydrolysis behavior and speciation under different conditions. The effects of pH and dilution ratio on Al species distribution were investigated by ferron assay. Experimental result showed that pH had a significant effect on Al species distribution for the three coagulants. Dilution ratio had little effects on Alb and Alc distribution in whole dilution process except the beginning for PACl1 and PACl2. The results indicated that transformation of Al depends largely on their original composition. AlCl3 was the most unstable coagulant among these three coagulants during hydrolysis process. PACl1 and PACl2 with significant amounts of highly charged and stable polynuclear aluminum hydrolysis products were less affected by the hydrolysis conditions and could maintain high speciation stability under various conditions.
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Affiliation(s)
- Changwei Zhao
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
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228
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Cheng J, Huang D, Zhang J, Yang W, Wang N, Sun Y, Wang K, Mo X, Bi S. Electrochemical behavior of lactate dehydrogenase immobilized on “silica sol–gel/nanometre-sized tridecameric aluminium polycation” modified gold electrode and its application. Analyst 2009; 134:1392-5. [DOI: 10.1039/b823096j] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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229
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Qian Z, Feng H, Yang W, Jin X, Bi S. Density functional study of the water exchange reaction of the polyoxocation GeO4Al12(OH)24(H2O)128+ (K-GeAl12) in aqueous solution. Dalton Trans 2009:8013-7. [DOI: 10.1039/b909278a] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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230
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Mensinger Z, Gatlin J, Meyers S, Zakharov L, Keszler D, Johnson D. Synthesis of Heterometallic Group 13 Nanoclusters and Inks for Oxide Thin-Film Transistors. Angew Chem Int Ed Engl 2008. [DOI: 10.1002/ange.200803514] [Citation(s) in RCA: 14] [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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231
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Mensinger Z, Gatlin J, Meyers S, Zakharov L, Keszler D, Johnson D. Synthesis of Heterometallic Group 13 Nanoclusters and Inks for Oxide Thin-Film Transistors. Angew Chem Int Ed Engl 2008; 47:9484-6. [DOI: 10.1002/anie.200803514] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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232
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Kikukawa Y, Yamaguchi S, Nakagawa Y, Uehara K, Uchida S, Yamaguchi K, Mizuno N. Synthesis of a Dialuminum-Substituted Silicotungstate and the Diastereoselective Cyclization of Citronellal Derivatives. J Am Chem Soc 2008; 130:15872-8. [DOI: 10.1021/ja8014154] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Yuji Kikukawa
- Department of Applied Chemistry, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Syuhei Yamaguchi
- Department of Applied Chemistry, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Yoshinao Nakagawa
- Department of Applied Chemistry, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Kazuhiro Uehara
- Department of Applied Chemistry, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Sayaka Uchida
- Department of Applied Chemistry, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Kazuya Yamaguchi
- Department of Applied Chemistry, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Noritaka Mizuno
- Department of Applied Chemistry, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
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233
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Qian Z, Feng H, Yang W, Bi S. Theoretical Investigation of Water Exchange on the Nanometer-Sized Polyoxocation AlO4Al12(OH)24(H2O)127+ (Keggin-Al13) in Aqueous Solution. J Am Chem Soc 2008; 130:14402-3. [DOI: 10.1021/ja805503t] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Zhaosheng Qian
- School of Chemistry and Chemical Engineering, State Key Laboratory of Coordination Chemistry of China & Key Laboratory of MOE for Life Science, Nanjing University, Nanjing 210093, China
| | - Hui Feng
- School of Chemistry and Chemical Engineering, State Key Laboratory of Coordination Chemistry of China & Key Laboratory of MOE for Life Science, Nanjing University, Nanjing 210093, China
| | - Wenjing Yang
- School of Chemistry and Chemical Engineering, State Key Laboratory of Coordination Chemistry of China & Key Laboratory of MOE for Life Science, Nanjing University, Nanjing 210093, China
| | - Shuping Bi
- School of Chemistry and Chemical Engineering, State Key Laboratory of Coordination Chemistry of China & Key Laboratory of MOE for Life Science, Nanjing University, Nanjing 210093, China
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234
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Saukkoriipi JJ, Laasonen K. Density Functional Studies of the Hydrolysis of Aluminum (Chloro)Hydroxide in Water with CPMD and COSMO. J Phys Chem A 2008; 112:10873-80. [DOI: 10.1021/jp804176v] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | - Kari Laasonen
- Department of Chemistry, University of Oulu, P.O. Box 3000, Oulu FIN-90014, Finland
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235
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236
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Zhao H, Hu C, Liu H, Zhao X, Qu J. Role of aluminum speciation in the removal of disinfection byproduct precursors by a coagulation process. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2008; 42:5752-5758. [PMID: 18754504 DOI: 10.1021/es8006035] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Humic acid (HA) was extracted and separated into different molecular weight (MW) fractions, then coagulated by aluminum chloride and polyaluminum chloride (PACl). The removal of disinfection byproduct (DBP) precursors and the aluminum speciation variation of the coagulants were investigated in detail. In particular, the role of aluminum speciation in the removal of DBP precursors was discussed. During the coagulation process, AlCl3 hydrolyzed into dominating in situ Al13 species at pH 5.5. The in situ Al13 species exhibited better removal ability for haloacetic acid (HAA) precursors than PACl. At pH 7.5, in situ hydrolyzed Al13 species of AlCl3 decomposed into dimeric Al species. In this case, preformed Al13 of PACl had a high removal ability of HAA precursors. Specially, the greatest reduction of HAA precursors with a low MW (<30 kDa) was through charge neutralization at pH 5.5, and that of HAA precursors in high MW (> 30 kDa) fractions was through adsorption at pH 7.5. Different from HAA precursors, the in situ Al13 species did not have a high removal ability of trihalomethane (THM) precursors. Therefore, PACl exhibited a better removal ability of THM precursors than AlCl3 at different pH values. In the different MW fractions, the greatest reduction of THM precursors was through charge neutralization at pH 5.5.
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Affiliation(s)
- He Zhao
- State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
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237
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Yuan Q, Yin AX, Luo C, Sun LD, Zhang YW, Duan WT, Liu HC, Yan CH. Facile synthesis for ordered mesoporous gamma-aluminas with high thermal stability. J Am Chem Soc 2008; 130:3465-72. [PMID: 18284238 DOI: 10.1021/ja0764308] [Citation(s) in RCA: 309] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The facile synthesis of highly ordered mesoporous aluminas with high thermal stability and tunable pore sizes is systematically investigated. The general synthesis strategy is based on a sol-gel process associated with nonionic block copolymer as templates in ethanol solvent. Small-angle XRD, TEM, and nitrogen adsorption and desorption results show that these mesoporous aluminas possess a highly ordered 2D hexagonal mesostructure, which is resistant to high temperature up to 1000 degrees C. Ordered mesoporous structures with tunable pore sizes are obtained with various precursors, different acids as pH adjustors, and different block copolymers as templates. These mesoporous aluminas have large surface areas (ca. 400 m2/g), pore volumes (ca. 0.70 cm3/g), and narrow pore-size distributions. The influence of the complexation ability of anions and hydro-carboxylic acid, acid volatility, and other important synthesis conditions are discussed in detail. Utilizing this simple strategy, we also obtained partly ordered mesoporous alumina with hydrous aluminum nitrate as the precursor. FTIR pyridine adsorption measurements indicate that a large amount of Lewis acid sites exist in these mesoporous aluminas. These materials are expected to be good candidates in catalysis due to the uniform pore structures, large surface areas, tunable pore sizes, and large amounts of surface Lewis acid sites. Loaded with ruthenium, the representative mesoporous alumina exhibits reactant size selectivity in hydrogenation of acetone, D-glucose, and D-(+)-cellobiose as a test reaction, indicating the potential applications in shape-selective catalysis.
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Affiliation(s)
- Quan Yuan
- Beijing National Laboratory for Molecular Sciences, Peking University, Beijing 100871, China
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238
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Gatlin JT, Mensinger ZL, Zakharov LN, MacInnes D, Johnson DW. Facile Synthesis of the Tridecameric Al13 Nanocluster Al13(μ3-OH)6(μ2-OH)18(H2O)24(NO3)15. Inorg Chem 2008; 47:1267-9. [DOI: 10.1021/ic7020808] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Jason T. Gatlin
- Department of Chemistry and Materials Science Institute, University of Oregon, Eugene, Oregon 97403-1253 and the Oregon Nanoscience and Microtechnologies Institute (ONAMI), P.O. Box 2041, Corvallis, Oregon 97339
| | - Zachary L. Mensinger
- Department of Chemistry and Materials Science Institute, University of Oregon, Eugene, Oregon 97403-1253 and the Oregon Nanoscience and Microtechnologies Institute (ONAMI), P.O. Box 2041, Corvallis, Oregon 97339
| | - Lev N. Zakharov
- Department of Chemistry and Materials Science Institute, University of Oregon, Eugene, Oregon 97403-1253 and the Oregon Nanoscience and Microtechnologies Institute (ONAMI), P.O. Box 2041, Corvallis, Oregon 97339
| | - David MacInnes
- Department of Chemistry and Materials Science Institute, University of Oregon, Eugene, Oregon 97403-1253 and the Oregon Nanoscience and Microtechnologies Institute (ONAMI), P.O. Box 2041, Corvallis, Oregon 97339
| | - Darren W. Johnson
- Department of Chemistry and Materials Science Institute, University of Oregon, Eugene, Oregon 97403-1253 and the Oregon Nanoscience and Microtechnologies Institute (ONAMI), P.O. Box 2041, Corvallis, Oregon 97339
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239
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Potentiometric determination of the ‘formal’ hydrolysis ratio of aluminium species in aqueous solutions. Anal Chim Acta 2008; 607:61-73. [DOI: 10.1016/j.aca.2007.11.026] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2007] [Revised: 11/13/2007] [Accepted: 11/13/2007] [Indexed: 11/22/2022]
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240
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Deschaume O, Fournier A, Shafran KL, Perry CC. Interactions of aluminium hydrolytic species with biomolecules. NEW J CHEM 2008. [DOI: 10.1039/b805406c] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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241
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Nyman M, Bieker JM, Thoma SG, Trudell DE. Investigation of inorganic cluster–surfactant flocculants for virion sequestration and removal from aqueous media. J Colloid Interface Sci 2007; 316:968-76. [PMID: 17888936 DOI: 10.1016/j.jcis.2007.08.015] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2007] [Revised: 08/02/2007] [Accepted: 08/06/2007] [Indexed: 10/23/2022]
Abstract
Anionic polyoxometalates or cationic aluminum clusters when combined with a surfactant of an opposite charge form hydrophobic precipitates that are approximately lamellar with alternating layers of interdigitated surfactant tails and inorganic clusters. The charged surfactant heads are associated with the inorganic cluster layers. When these phases self-assemble and precipitate from aqueous media spiked with a virus titer, either bovine enterovirus (BEV) or influenza A, the precipitates effectively sequester the virions via an enmeshment process. These studies were done via precipitation and filtration of the cluster-surfactant floc in the presence of the virus, followed by reverse transcriptase polymerase chain reaction (rRT-PCR) analysis of the filtrate. Efficacy of these cluster-surfactant phases for virion sequestration is variable as a function of their solubility, the size of colloid formed in solution, and their degree of long-range order. Generally less soluble, poorly ordered precipitates that form the largest colloids are the most effective virion sequestering media. Cluster-surfactant phases were characterized in solution by nuclear magnetic resonance (NMR) and dynamic light scattering (DLS); and in the solid-state by powder X-ray diffraction and solid-state magic angle spinning (MAS) NMR.
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Affiliation(s)
- May Nyman
- Sandia National Laboratories, P.O. Box 5800, Albuquerque, NM 87185, USA.
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242
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Feng C, Tang H, Wang D. Differentiation of hydroxyl-aluminum species at lower OH/Al ratios by combination of 27Al NMR and Ferron assay improved with kinetic resolution. Colloids Surf A Physicochem Eng Asp 2007. [DOI: 10.1016/j.colsurfa.2007.04.043] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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243
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Balogh E, Todea AM, Müller A, Casey WH. Rates of Ligand Exchange between >FeIII−OH2 Functional Groups on a Nanometer-Sized Aqueous Cluster and Bulk Solution. Inorg Chem 2007; 46:7087-92. [PMID: 17661461 DOI: 10.1021/ic7009308] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Variable-temperature 17O NMR experiments were conducted on the nanometer-sized Keplerate Mo72Fe30 cluster, with the stoichiometry [Mo72Fe30O252(CH3COO)12[Mo2O7(H2O)]2[H2Mo2O8(H2O)](H2O)91]. approximately 150H2O. This molecule contains on its surface 30 Fe(H2O) groups forming a well-defined icosidodecahedron, and we estimated the rates of exchange of the isolated >FeIII-OH2 waters with bulk aqueous solution. Both longitudinal and transverse 17O-relaxation times were measured, as well as chemical shifts, and these parameters were then fit to the Swift-Connick equations in order to obtain the rate parameters. Correspondingly, we estimate: k(ex)298 = 6.7(+/-0.8) x 106 s-1, which is about a factor of approximately 4 x 104 times larger than the corresponding rate coefficient for the Fe(OH2)63+ ion of k(ex)298 = 1.6 x 102 s-1 (Grant and Jordan, 1981; Inorg. Chem. 20, 55-60) and DeltaH and DeltaS are 26.3 +/- 0.6 kJ mol-1 and -26 +/- 0.9 J mol-1 K-1, respectively. High-pressure 17O NMR experiments were also conducted, but the cluster decomposed slightly under pressure, which precluded confident quantitative estimation of the DeltaV. However, the increase in the reduced transverse-relaxation time with pressure suggests a dissociative character, such as a D or Id mechanism. The enhanced reactivity of waters on the Mo72Fe30 cluster is associated with an increase in the FeIII-OH2 bond length in the solid state of approximately 0.1 A relative to the Fe(OH2)63+ ion, suggesting that a correlation exists between the FeIII-OH2 bond length and k(ex)298. Although there are only few high-spin Fe(III) complexes where both exchange rates and structural data are available, these few seem to support a general correlation.
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Affiliation(s)
- Edina Balogh
- Department of Chemistry, Department of Geology, University of California, Davis, CA 95616, USA
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244
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Balogh E, Anderson TM, Rustad JR, Nyman M, Casey WH. Rates of Oxygen-Isotope Exchange between Sites in the [HxTa6O19](8-x)−(aq) Lindqvist Ion and Aqueous Solutions: Comparisons to [HxNb6O19](8-x)−(aq). Inorg Chem 2007; 46:7032-9. [PMID: 17658746 DOI: 10.1021/ic700845e] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Rates of steady oxygen-isotope exchange differ in interesting ways for two sets of structural oxygens in the [HxTa6O19](8-x)-(aq) Lindqvist ion when compared to published data on the [HxNb6O19]8-x(aq) version. Because of the lanthanide contraction, the [HxTa6O19](8-x)-(aq) and [HxNb6O19](8-x)-(aq) ions are virtually isostructural and differ primarily in a full core (Kr vs Xe) and the 4f14 electrons in the [HxTa6O19](8-x)-(aq) ion. For both molecules, both pH-dependent and -independent pathways are evident in isotopic exchange of the 12 mu2-O(H) and 6 eta=O sites. Rate parameters for eta=O exchange at conditions where there is no pH dependence are, for the Ta(V) and Nb(V) versions respectively, K(298)(0) = 2.72 x 10(-5) s(-1) and 9.7 x 10(-6) s(-1), DeltaH = 83.6 +/- 3.2 and 89.4 kJ.mol(-1), and DeltaS = -51.0 +/- 10.6 and -42.9 J.mol(-1).K-1. For the mu2-O sites, K(298)(0) = 1.23 x 10(-6) s(-1), DeltaH = 70.3 +/- 9.7 and 88.0 kJ.mol(-1), and DeltaS = -116.1 +/- 32.7 and -29.4 J.mol(-1).K-1. Protonation of the 6 eta=O sites is energetically unfavored relative to the 12 mu2-O bridges in both molecules, although not equally so. Experimentally, protonation labilizes both the mu2-O(H) and eta=O sites to isotopic exchange in both molecules. Density-functional electronic-structure calculations indicate that proton affinities of structural oxygens in the two molecules differ with the [HxTa6O19](8-x)-(aq) anion having a smaller affinity to protonate than the [HxNb6O19]8-x(aq) ion. This difference in proton affinities is evident in the solution chemistry as pKa = 11.5 for the [HTa6O19]7-(aq) ion and pKa = 13.6 for the [HNb6O19]7-(aq) ion. Most striking is the observation that eta=O sites isotopically equilibrate faster than the mu2-O sites for the [HxTa6O19](8-x)-(aq) Lindqvist ion but slower for the [HxNb6O19](8-x)-(aq) ion, indicating that predictions about site reactivities in complicated structures, such as the interface of aqueous solutions and oxide solids, should be approached with great caution.
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Affiliation(s)
- Edina Balogh
- Departments of Chemistry and Geology, University of California, Davis, CA 95616, USA
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245
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Michel FM, Ehm L, Antao SM, Lee PL, Chupas PJ, Liu G, Strongin DR, Schoonen MAA, Phillips BL, Parise JB. The Structure of Ferrihydrite, a Nanocrystalline Material. Science 2007; 316:1726-9. [PMID: 17525301 DOI: 10.1126/science.1142525] [Citation(s) in RCA: 370] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Despite the ubiquity of ferrihydrite in natural sediments and its importance as an industrial sorbent, the nanocrystallinity of this iron oxyhydroxide has hampered accurate structure determination by traditional methods that rely on long-range order. We uncovered the atomic arrangement by real-space modeling of the pair distribution function (PDF) derived from direct Fourier transformation of the total x-ray scattering. The PDF for ferrihydrite synthesized with the use of different routes is consistent with a single phase (hexagonal space group P6(3)mc; a = approximately 5.95 angstroms, c = approximately 9.06 angstroms). In its ideal form, this structure contains 20% tetrahedrally and 80% octahedrally coordinated iron and has a basic structural motif closely related to the Baker-Figgis delta-Keggin cluster. Real-space fitting indicates structural relaxation with decreasing particle size and also suggests that second-order effects such as internal strain, stacking faults, and particle shape contribute to the PDFs.
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Affiliation(s)
- F Marc Michel
- Center for Environmental Molecular Science (CEMS), Stony Brook University, Stony Brook, NY 11794, USA.
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246
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Wang J, Rustad JR, Casey WH. Calculation of Water-Exchange Rates on Aqueous Polynuclear Clusters and at Oxide−Water Interfaces. Inorg Chem 2007; 46:2962-4. [PMID: 17355130 DOI: 10.1021/ic070079+] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The rates of a wide variety of reactions in aqueous coordination compounds can be correlated with lifetimes of water molecules in the inner-coordination shell of the metal. For simple octahedral metal ions, these lifetimes span approximately 1020 but are unknown, and experimentally inaccessible, for reactive sites in interfacial environments. Using recent data on nanometer-sized aqueous aluminum clusters, we show that lifetimes can be calculated from reactive-flux molecular dynamics simulations. Rates scale with the calculated metal-water bond lengths. Surprisingly, on all aluminum(III) mineral surface sites investigated, waters have lifetimes in the range of 10-8-10-10 s, making the surface sites as fast as the most reactive ions in the solution.
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Affiliation(s)
- Jianwei Wang
- Department of Geology, University of California, Davis, California 95616, USA
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247
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Hanauer H, Puchta R, Clark T, van Eldik R. Searching for Stable, Five-Coordinate Aquated Al(III) Species. Water Exchange Mechanism and Effect of pH. Inorg Chem 2007; 46:1112-22. [PMID: 17249654 DOI: 10.1021/ic061284c] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Density functional theory calculations have been performed for the water exchange mechanism of aquated Al(III). The effect of pH was considered by studying the exchange processes for [Al(H2O)6]3+ and its conjugated base, [Al(H2O)5OH]2+. Both complexes were found to exchange water in a dissociative way with activation energies (EA) of 15.9 and 10.2 kcal/mol, respectively. The influence of solvent molecules on the gas-phase cluster model was considered by the addition of up to four water molecules to the model system. The stabilizing effect of the solvent on the transition state decreases EA to 8.6 (hexa-aqua complex) and 7.6 (monohydroxo complex) kcal/mol, whereas EA for all hydroxo species is consistently significantly lower than those for the related aqua systems, which indicates a much faster water exchange rate. For the hydroxo complex, all calculated five-coordinate intermediates, nH2O.[Al(H2O)4(OH)]2+ (n = 1, 2, 3, 4, 5), are more stable than the corresponding six-coordinate reactants. Our results therefore suggest the presence of a stable five-coordinate species of aquated Al(III), namely, the [Al(H2O)4(OH)]2+ complex.
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Affiliation(s)
- Hans Hanauer
- Institute for Inorganic Chemistry, University of Erlangen-Nürnberg, Egerlandstrasse 1, 91058 Erlangen, Germany
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248
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Sarpola AT, Saukkoriipi JJ, Hietapelto VK, Jalonen JE, Jokela JT, Joensuu PH, Laasonen KE, Rämö JH. Identification of hydrolysis products of AlCl3·6H2O in the presence of sulfate by electrospray ionizationtime-of-flight mass spectrometry and computational methods. Phys Chem Chem Phys 2007; 9:377-88. [PMID: 17199154 DOI: 10.1039/b614814j] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
ElectroSpray Ionization-Mass Spectrometry (ESI-MS) and computational methods (DFT, MP2, and COSMO) were used to investigate the hydrolysis products of aluminium chloride as a function of sulfate concentration at pH 3.7. With the aid of computational chemistry, structural information was deduced from the chemical compositions observed with ESI-MS. Many novel types of hydrolysis products were noted, revealing that our present understanding of aluminium speciation is too simple. The role of counterions was found to be critical: the speciation of aluminium changed markedly as a function of sulfate concentration. Ab initio calculations were used to reveal the energetically most favoured structures of aluminium sulfate anions and cations selected from the ESI-MS results. Several interesting observations were made. Most importantly, the bonding behaviour of the sulfate group changed as the number of aqua ligands increased. The accompanying structural rearrangement of the clusters revealed the highly active role of sulfate as a ligand. The gas phase calculations were expanded to the aquatic environment using a conductor-like screening model. As expected, the bonding behaviour of the sulfate group in the minimum energy structures was distinctly different in the aquatic environment compared to the gas phase. Together, these methods open a new window for research in the solution chemistry of aluminium species.
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Affiliation(s)
- Arja T Sarpola
- Water Resources and Environmental Engineering Laboratory, University of Oulu, Linnanmaa, Finland.
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Rustad JR, Stack AG. Molecular Dynamics Calculation of the Activation Volume for Water Exchange on Li+. J Am Chem Soc 2006; 128:14778-9. [PMID: 17105267 DOI: 10.1021/ja066022o] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The activation volume of water exchange around Li+ (aq) was determined from reactive flux calculations using molecular dynamics simulations with a classical force field. The barrier height for exchange decreases with pressure, giving a negative activation volume, in agreement with the current paradigm for inferring exchange mechanism from activation volume. However, it is also demonstrated that pressure-dependent transmission effects make a significant contribution to the overall activation volume. These calculations indicate that small activation volumes should not be regarded as mechanistically indicative because of the potential contributions from transmission effects.
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Affiliation(s)
- James R Rustad
- Department of Geology, University of California-Davis, One Shields Avenue, Davis, CA 95616, USA.
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Black JR, Nyman M, Casey WH. Rates of Oxygen Exchange between the [HxNb6O19]8-x(aq) Lindqvist Ion and Aqueous Solutions. J Am Chem Soc 2006; 128:14712-20. [PMID: 17090059 DOI: 10.1021/ja065529w] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Oxygen-isotope-exchange rates were measured between sites in the Lindqvist-type [H(x)()Nb(6)O(19)](8)(-)(x)()((aq)) polyoxoanion and aqueous solution as a function of pH and temperature. The ion has a central mu(6)-O that is inert to exchange, 12 mu(2)-O(H), and 6 eta-O. The potassium salt of this ion is recrystallized in (17)O-enriched water to (17)O-label the anion, which is then redissolved into isotopically normal water so that the (17)O NMR signals from structural oxygens can be followed as a function of time. Because the central mu(6)-O retains its (17)O signal throughout the experiments, it is clear that the polyoxoanion remains intact during isotopic equilibration of the other structural oxygens. At pH conditions where the [HNb(6)O(19)](7)(-) ion predominates, the mu(2)-O(H) sites isotopically exchange with solution about an order of magnitude more rapidly than the eta-O sites. Yet, we observe that the terminal and bridging oxo sites react at nearly the same rates when the ion is coordinated to 2-3 protons and possibly when it is unprotonated. On the basis of molecular models and experimental kinetic data, we propose metastable polymorphs of the hexaniobate structure where four of the mu(2)-O(H) and eta-O sites are temporarily equivalent and bonded to a coordinatively unsaturated Nb(V). This hypothesized intermediate allows facile access to bulk water molecules for exchange but cannot fully explain the kinetic results and additional experiments on other Lindvist ions are required.
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Affiliation(s)
- Jay R Black
- Department of Chemistry and Geology, University of California, Davis, California 95616, USA
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