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Wang Y, Wang G, Bowron DT, Zhu F, Hannon AC, Zhou Y, Liu X, Shi G. Unveiling the structure of aqueous magnesium nitrate solutions by combining X-ray diffraction and theoretical calculations. Phys Chem Chem Phys 2022; 24:22939-22949. [PMID: 36125259 DOI: 10.1039/d2cp01828d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The structure of aqueous magnesium nitrate solution is gaining significant interest among researchers, especially whether contact ion pairs exist in concentrated solutions. Here, combining X-ray diffraction experiments, quantum chemical calculations and ab initio molecular dynamics simulations, we report that the [Mg(NO3)2] molecular structure in solution from the coexistence of a free [Mg(H2O)6]2+ octahedral supramolecular structure with a free [NO3(H2O)n]- (n = 11-13) supramolecular structure to an [Mg2+(H2O)n(NO3-)m] (n = 3, 4, 5; m = 3, 2, 1) associated structure with increasing concentration. Interestingly, two hydration modes of NO3--the nearest neighbor hydration with a hydration distance less than 3.9 Å and the next nearest neighbor hydration with hydration distance ranging from 3.9 to 4.3 Å-were distinguished. With an increase in the solution concentration, the hydrated NO3- ions lost outer layer water molecules, and the hexagonal octahedral hydration structure of [Mg(H2O)62+] was destroyed, resulting in direct contact between Mg2+ and NO3- ions in a monodentate way. As the concentration of the solution further increased, NO3- ions replaced water molecules in the hydration layer of Mg2+ to form three-ion clusters and even more complex chains or linear ion clusters.
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Affiliation(s)
- Yunxia Wang
- Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt Lake Resources, Qinghai Provincial Key Laboratory of Resources Chemistry of Salt Lakes, Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Xining 81008, China. .,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Guangguo Wang
- Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt Lake Resources, Qinghai Provincial Key Laboratory of Resources Chemistry of Salt Lakes, Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Xining 81008, China. .,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Daniel T Bowron
- ISIS Facility, STFC, Rutherford Appleton Laboratory, Chilton, Didcot, Oxon OX11 0QX, UK.
| | - Fayan Zhu
- Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt Lake Resources, Qinghai Provincial Key Laboratory of Resources Chemistry of Salt Lakes, Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Xining 81008, China. .,ISIS Facility, STFC, Rutherford Appleton Laboratory, Chilton, Didcot, Oxon OX11 0QX, UK.
| | - Alex C Hannon
- ISIS Facility, STFC, Rutherford Appleton Laboratory, Chilton, Didcot, Oxon OX11 0QX, UK.
| | - Yongquan Zhou
- Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt Lake Resources, Qinghai Provincial Key Laboratory of Resources Chemistry of Salt Lakes, Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Xining 81008, China.
| | - Xing Liu
- Shanghai Applied Radiation Institute, Shanghai University, Shanghai 200444, China
| | - Guosheng Shi
- Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt Lake Resources, Qinghai Provincial Key Laboratory of Resources Chemistry of Salt Lakes, Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Xining 81008, China. .,Shanghai Applied Radiation Institute, Shanghai University, Shanghai 200444, China.,Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou 325001, China
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Rudolph WW, Fischer D, Irmer G. Hydration and Ion-Pair Formation of NaNO 3(aq): A Vibrational Spectroscopic and Density Functional Theory Study. APPLIED SPECTROSCOPY 2021; 75:395-411. [PMID: 33393351 DOI: 10.1177/0003702820986861] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Qualitative and quantitative Raman and infrared measurements on sodium nitrate (NaNO3) solutions have been carried out over a wide concentration range (5.56 × 10-6-7.946 mol/L) in water and heavy water. The Raman spectra were measured from 4000 cm-1 to low wavenumbers at 45 cm-1. Band fit analysis on the profile of the 1047 cm-1 band, ν1(a1') NO3- measured at high resolution at 0.90 cm-1 produced a small contribution at 1027 cm-1 of the isotopomer N16O218O(aq). The effect of solute concentration on the Raman and infrared bands has been systematically recorded. Extrapolation of the experimental data resulted in values for all the nitrate bands of the "free", i.e., fully hydrated NO3-(aq). However, even in dilute solutions, the vibrational symmetry of the hydrated NO3-(aq) is broken and the antisymmetric N-O stretch, which is degenerate for the isolated anion, is split by 56 cm-1. At concentrations >2.5 mol/L, direct contact between Na+ and NO3- was observed and accompanied by large band parameter changes. DFT calculations on NO3-(H2O)n (n = 1-3) led to optimized geometries and vibrational frequencies which reproduced the measured ones within an accuracy of 1%. A hydrated gas phase species Na+(H2O)10NO3- was optimized resulting in the geometry and symmetry of the nitrate, which is bound in an antisymmetric bidentate fashion with the nitrate possessing C1. The ν1 Na+(OH2) breathing mode in aqueous solution appears at 189 cm-1, whereas in heavy water, ν1 Na+(OD2) is shifted to 175.6 cm-1 due to the isotope effect. DFT calculations on hydrated Na+(OH2)n gas phase clusters provided realistic Na+ hydrate structures with n = 4 and 5, which resembled the measured frequency of ν1 Na+ OH2 mode quite well. Quantitative Raman analysis employing the symmetric stretching band, ν1(a1') NO3-, has been carried out down to concentrations as low as 5.56 × 10-6 mol/L. The in-plane deformation mode ν4(e') in the Raman scattering at higher concentrations has been used as an indicator band for directly coordinated NO3-.
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Affiliation(s)
- Wolfram W Rudolph
- Department of Hospital Infection Control, Technical University Dresden, Universitätsklinikum Carl Gustav Carus Dresden, Dresden, Germany
| | | | - Gert Irmer
- Technische Universität Bergakademie Freiberg, Institut für Theoretische Physik, Freiberg, Germany
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Yadav S, Chandra A. Solvation Shell of the Nitrite Ion in Water: An Ab Initio Molecular Dynamics Study. J Phys Chem B 2020; 124:7194-7204. [PMID: 32706258 DOI: 10.1021/acs.jpcb.0c02221] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We performed ab initio molecular dynamics simulation of a nitrite ion in water to investigate the structural and dynamical properties of its hydration shell. The nitrite ion is found to exhibit strong asymmetry toward hydrogen bonding due to its two different types of hydrogen bond acceptor sites. This difference is better captured through further partitioning of the hydration shell into its proximal and distal regions. The frequency shifts of the stretch modes of hydration shell water reveal that the nitrogen site forms a stronger hydrogen bond than its oxygen sites with the latter forming hydrogen bonds, which are similar in strength to that between a pair of water molecules. The escape dynamics of water from the hydration shell is found to be rather slow, which seems to classify the nitrite ion as a structure-maker. However, the dynamics of orientational and hydrogen bond relaxation reveal a faster mobility of water molecules in the hydration shell than bulk water in spite of strong ion-water interactions. It is found that the nitrite ion can hold water molecules in its solvation shell and still make them rotate fast in its vicinity through switching of their hydrogen bonds between its nitrogen and oxygen acceptor sites. The dipole moment of the solute in water is also calculated in the present study.
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Affiliation(s)
- Sushma Yadav
- Department of Chemistry, Indian Institute of Technology Kanpur, 208016 Kanpur, India
| | - Amalendu Chandra
- Department of Chemistry, Indian Institute of Technology Kanpur, 208016 Kanpur, India
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Wang HW, Vlcek L, Neuefeind JC, Page K, Irle S, Simonson JM, Stack AG. Decoding Oxyanion Aqueous Solvation Structure: A Potassium Nitrate Example at Saturation. J Phys Chem B 2018; 122:7584-7589. [PMID: 29991255 DOI: 10.1021/acs.jpcb.8b05895] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The ability to probe the structure of a salt solution at the atomic scale is fundamentally important for our understanding of many chemical reactions and their mechanisms. The capability of neutron diffraction to "see" hydrogen (or deuterium) and other light isotopes is exceptional for resolving the structural complexity around the dissolved solutes in aqueous electrolytes. We have made measurements using oxygen isotopes on aqueous nitrate to reveal a small hydrogen-bonded water coordination number (3.9 ± 1.2) around a nitrate oxyanion. This is compared to estimates made using the existing method of nitrogen isotope substitution and those of computational simulations (>5-6 water molecules). The low water coordination number, combined with a comparison to classical molecular dynamics simulations, suggests that ion-pair formation is significant. This insight demonstrates the utility of experimental diffraction data for benchmarking atomistic computer simulations, enabling the development of more accurate intermolecular potentials.
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Yadav S, Chandra A. Preferential solvation, ion pairing, and dynamics of concentrated aqueous solutions of divalent metal nitrate salts. J Chem Phys 2017; 147:244503. [DOI: 10.1063/1.4996273] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Sushma Yadav
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208016, India
| | - Amalendu Chandra
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208016, India
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Yadav S, Choudhary A, Chandra A. A First-Principles Molecular Dynamics Study of the Solvation Shell Structure, Vibrational Spectra, Polarity, and Dynamics around a Nitrate Ion in Aqueous Solution. J Phys Chem B 2017; 121:9032-9044. [DOI: 10.1021/acs.jpcb.7b06809] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Sushma Yadav
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur, India 208016
| | - Ashu Choudhary
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur, India 208016
| | - Amalendu Chandra
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur, India 208016
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Chialvo AA, Vlcek L. NO3– Coordination in Aqueous Solutions by 15N/14N and 18O/natO Isotopic Substitution: What Can We Learn from Molecular Simulation? J Phys Chem B 2014; 119:519-31. [DOI: 10.1021/jp510355u] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Ariel A. Chialvo
- Chemical
Sciences Division, Geochemistry and Interfacial Sciences Group, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6110, United States
| | - Lukas Vlcek
- Chemical
Sciences Division, Geochemistry and Interfacial Sciences Group, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6110, United States
- Joint
Institute for Computational Sciences, Oak Ridge National Laboratory, Oak
Ridge, Tennessee 37831-6173, United States
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Mayanovic RA, Anderson AJ, Bajt S. Microbeam XAFS Investigations on Fluid Inclusions. ACTA ACUST UNITED AC 2011. [DOI: 10.1557/proc-437-201] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
AbstractIn this paper, we discuss the use of x-ray absorption fine structure (XAFS) techniques for the determination of structure of metal complexes in fluid inclusions heated to elevated temperatures. Analysis of Zn K-edge XAFS spectra measured from a single hypersaline fluid inclusion in quartz shows that the ZnCl42- complex is dominant at all temperatures up to and including 430 °C. The Zn-Cl bond length was found to decrease uniformly with temperature, up to nearly 2% at 430 °C in comparison to the value at 25 °C. The Zn-Cl mean-square relative displacement increased linearly with temperature, from a value of 0.0043 Å2 at 25 °C to 0.0089 Å2 at 430 °C.
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Megyes T, Bálint S, Peter E, Grósz T, Bakó I, Krienke H, Bellissent-Funel MC. Solution structure of NaNO3 in water: diffraction and molecular dynamics simulation study. J Phys Chem B 2009; 113:4054-64. [PMID: 19231825 DOI: 10.1021/jp806411c] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The structure of a series of aqueous sodium nitrate solutions (1.9-7.6 M) was studied using a combination of experimental and theoretical methods. The results obtained from diffraction (X-ray, neutron) and molecular dynamics simulation have been compared and the capabilities and limitations of the methods in describing solution structure are discussed. For the solutions studied, diffraction methods were found to perform very well in description of hydration spheres of the sodium ion but do not yield detailed structural information on the anion's hydration structure. Molecular dynamics simulations proved to be a suitable tool in the detailed interpretation of the hydration sphere of ions, ion pair formation, and bulk structure of solutions.
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Affiliation(s)
- Tünde Megyes
- Institute of Structural Chemistry, Chemical Research Center of the Hungarian Academy of Sciences, Budapest, Hungary.
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Lu GW, Li YF, Sun W, Li CX. Molecular Dynamics Simulation of Hydration Structure of KNO3Electrolyte Solution. CHINESE J CHEM PHYS 2007. [DOI: 10.1360/cjcp2007.20(1).22.9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Lu GW, Li * CX, Wang WC, Wang ZH. A Monte Carlo simulation on structure and thermodynamics of potassium nitrate electrolyte solution. Mol Phys 2005. [DOI: 10.1080/00268970410001683834] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Bowron DT. Structure and interactions in simple solutions. Philos Trans R Soc Lond B Biol Sci 2004; 359:1167-79; discussion 1179-80. [PMID: 15306374 PMCID: PMC1693403 DOI: 10.1098/rstb.2004.1496] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Neutron scattering with hydrogen/deuterium isotopic substitution techniques has been used to investigate the full range of structural interactions in a dilute 0.02 mol fraction solution of tertiary butanol in water, both in the absence and in the presence of a small amount of sodium chloride. Emphasis is given to the detailed pictures of the intermolecular interactions that have been derived using the empirical potential structure refinement technique. Analysis has been performed to the level of the spatial density distribution functions that illustrate the orientational dependence of the intermolecular interactions between all combinations of molecular and ionic components. The results show the key structural motifs involved in the interactions between the various components in a complex aqueous system. They underline the structural versatility of the water molecule in accommodating a range of different kinds of interactions while retaining its characteristic first-neighbour interaction geometry. Within this framework, the results highlight the complex interplay between the polar, non-polar and charged molecular interactions that exist in the system.
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Affiliation(s)
- D T Bowron
- ISIS Facility, CCLRC Rutherford Appleton Laboratory, Chilton, Didcot OX11 0QX, UK.
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Mason PE, Neilson GW, Dempsey CE, Barnes AC, Cruickshank JM. The hydration structure of guanidinium and thiocyanate ions: implications for protein stability in aqueous solution. Proc Natl Acad Sci U S A 2003; 100:4557-61. [PMID: 12684536 PMCID: PMC404697 DOI: 10.1073/pnas.0735920100] [Citation(s) in RCA: 276] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Neutron diffraction experiments were carried out on aqueous solutions containing either guanidinium or thiocyanate ions. The first-order difference method of neutron diffraction and isotopic substitution was applied, and the hydration structures of two of nature's strongest denaturant ions were determined. Each ion is shown to interact weakly with water: Guanidinium has no recognizable hydration shell and is one of the most weakly hydrated cations yet characterized. Hydration of thiocyanate is characterized by a low coordination number involving around one hydrogen-bonded water molecule and approximately two water molecules weakly interacting through "hydration bonds." The weak hydration of these denaturant ions strongly supports suggestions that a major contribution to the denaturant effect is the preferential interaction of the denaturant with the protein surface. By contrast, solute species such as many sugars and related polyols that stabilize proteins are strongly hydrated and are thus preferentially retained in the bulk solvent and excluded from the protein surface.
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Affiliation(s)
- P E Mason
- Department of Physics, University of Bristol, Tyndall Avenue, Bristol BS8 1TL, United Kingdom
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15
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Naganawa H, Tachimori S. Study of Hydration and Ionization of Nitric Acid in Benzene. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 1994. [DOI: 10.1246/bcsj.67.2690] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Kataoka Y. Molecular Dynamics Simulation of Aqueous MNO3(M = Li, Na, K, Rb, and Cs) Solutions. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 1993. [DOI: 10.1246/bcsj.66.2478] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Kameda Y, Saitoh H, Uemura O. The Hydration Structure of NO3−in Concentrated Aqueous Sodium Nitrate Solutions. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 1993. [DOI: 10.1246/bcsj.66.1919] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Johansson G. Structures of Complexes in Solution Derived from X-Ray Diffraction Measurements. ADVANCES IN INORGANIC CHEMISTRY 1992. [DOI: 10.1016/s0898-8838(08)60260-3] [Citation(s) in RCA: 71] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Adya AK, Neilson GW. Structure of a 50 mol kg–1aqueous solution of ammonium nitrate at 373 K by the isotopic difference method of neutron diffraction. ACTA ACUST UNITED AC 1991. [DOI: 10.1039/ft9918700279] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Rosi B, Fontana MP. Molecular reorientations and local structure in nitrate aqueous solutions. J Chem Phys 1987. [DOI: 10.1063/1.453471] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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