CuCl Complexation in the Vapor Phase: Insights from Ab Initio Molecular Dynamics Simulations
We investigated the hydration of the CuCl0 complex in HCl-bearing water vapor at 350°C and a vapor-like fluid density between 0.02 and 0.09 g/cm3 using ab initio molecular dynamics (MD) simulations. The simulations reveal that one water molecule is strongly bonded to Cu(I) (first coordination shell)...
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| Format: | Article |
| Language: | English |
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Wiley
2018-01-01
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| Series: | Geofluids |
| Online Access: | http://dx.doi.org/10.1155/2018/4279124 |
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| author | Yuan Mei Weihua Liu A. A. Migdiov Joël Brugger A. E. Williams-Jones |
| author_facet | Yuan Mei Weihua Liu A. A. Migdiov Joël Brugger A. E. Williams-Jones |
| author_sort | Yuan Mei |
| collection | DOAJ |
| description | We investigated the hydration of the CuCl0 complex in HCl-bearing water vapor at 350°C and a vapor-like fluid density between 0.02 and 0.09 g/cm3 using ab initio molecular dynamics (MD) simulations. The simulations reveal that one water molecule is strongly bonded to Cu(I) (first coordination shell), forming a linear [H2O-Cu-Cl]0 moiety. The second hydration shell is highly dynamic in nature, and individual configurations have short life-spans in such low-density vapors, resulting in large fluctuations in instantaneous hydration numbers over a timescale of picoseconds. The average hydration number in the second shell (m) increased from ~0.5 to ~3.5 and the calculated number of hydrogen bonds per water molecule increased from 0.09 to 0.25 when fluid density (which is correlated to water activity) increased from 0.02 to 0.09 g/cm3 (fH2O 1.72 to 2.05). These changes of hydration number are qualitatively consistent with previous solubility studies under similar conditions, although the absolute hydration numbers from MD were much lower than the values inferred by correlating experimental Cu fugacity with water fugacity. This could be due to the uncertainties in the MD simulations and uncertainty in the estimation of the fugacity coefficients for these highly nonideal “vapors” in the experiments. Our study provides the first theoretical confirmation that beyond-first-shell hydrated metal complexes play an important role in metal transport in low-density hydrothermal fluids, even if it is highly disordered and dynamic in nature. |
| format | Article |
| id | doaj-art-bf739c89c47145ada1a0ce1c1101d5de |
| institution | Kabale University |
| issn | 1468-8115 1468-8123 |
| language | English |
| publishDate | 2018-01-01 |
| publisher | Wiley |
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| series | Geofluids |
| spelling | doaj-art-bf739c89c47145ada1a0ce1c1101d5de2025-02-03T06:01:35ZengWileyGeofluids1468-81151468-81232018-01-01201810.1155/2018/42791244279124CuCl Complexation in the Vapor Phase: Insights from Ab Initio Molecular Dynamics SimulationsYuan Mei0Weihua Liu1A. A. Migdiov2Joël Brugger3A. E. Williams-Jones4CSIRO Mineral Resources, Clayton, VIC 3168, AustraliaCSIRO Mineral Resources, Clayton, VIC 3168, AustraliaEarth and Environmental Division, Los Alamos National Laboratory, M.S. J535, P.O. Box 1663, Los Alamos, NM 87545, USASchool of Earth, Atmosphere and Environment, Monash University, VIC 3800, AustraliaEarth and Planetary Sciences, McGill University, 3450 University Street, Montreal, QC, H3A 0E8, CanadaWe investigated the hydration of the CuCl0 complex in HCl-bearing water vapor at 350°C and a vapor-like fluid density between 0.02 and 0.09 g/cm3 using ab initio molecular dynamics (MD) simulations. The simulations reveal that one water molecule is strongly bonded to Cu(I) (first coordination shell), forming a linear [H2O-Cu-Cl]0 moiety. The second hydration shell is highly dynamic in nature, and individual configurations have short life-spans in such low-density vapors, resulting in large fluctuations in instantaneous hydration numbers over a timescale of picoseconds. The average hydration number in the second shell (m) increased from ~0.5 to ~3.5 and the calculated number of hydrogen bonds per water molecule increased from 0.09 to 0.25 when fluid density (which is correlated to water activity) increased from 0.02 to 0.09 g/cm3 (fH2O 1.72 to 2.05). These changes of hydration number are qualitatively consistent with previous solubility studies under similar conditions, although the absolute hydration numbers from MD were much lower than the values inferred by correlating experimental Cu fugacity with water fugacity. This could be due to the uncertainties in the MD simulations and uncertainty in the estimation of the fugacity coefficients for these highly nonideal “vapors” in the experiments. Our study provides the first theoretical confirmation that beyond-first-shell hydrated metal complexes play an important role in metal transport in low-density hydrothermal fluids, even if it is highly disordered and dynamic in nature.http://dx.doi.org/10.1155/2018/4279124 |
| spellingShingle | Yuan Mei Weihua Liu A. A. Migdiov Joël Brugger A. E. Williams-Jones CuCl Complexation in the Vapor Phase: Insights from Ab Initio Molecular Dynamics Simulations Geofluids |
| title | CuCl Complexation in the Vapor Phase: Insights from Ab Initio Molecular Dynamics Simulations |
| title_full | CuCl Complexation in the Vapor Phase: Insights from Ab Initio Molecular Dynamics Simulations |
| title_fullStr | CuCl Complexation in the Vapor Phase: Insights from Ab Initio Molecular Dynamics Simulations |
| title_full_unstemmed | CuCl Complexation in the Vapor Phase: Insights from Ab Initio Molecular Dynamics Simulations |
| title_short | CuCl Complexation in the Vapor Phase: Insights from Ab Initio Molecular Dynamics Simulations |
| title_sort | cucl complexation in the vapor phase insights from ab initio molecular dynamics simulations |
| url | http://dx.doi.org/10.1155/2018/4279124 |
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