Al-Madhagi, LH orcid.org/0000-0001-7498-6157, Chang, S-Y, Balasubramanian, M et al. (5 more authors) (2018) X-ray Raman scattering: a new in situ probe of molecular structure during nucleation and crystallization from liquid solutions. CrystEngComm, 20 (43). pp. 6871-6884. ISSN 1466-8033
Abstract
X-ray Raman scattering (XRS) has been used for in situ probing of solute molecule speciation in solution during cooling crystallization. The C and N K-edges of aqueous imidazole were measured as a function of temperature to monitor the transition from the undersaturated state through supersaturation to crystallization. A new jacketed-vessel crystallizer with internal flow was used, which enables thermal control and minimizes radiation damage. We have demonstrated that the C and N K-edges of imidazole are sensitive to changes in local bonding. In line with this, an abrupt change in the N K-edge fine structure indicates the onset of desolvation and crystallization from the supersaturated solution. In contrast, negligible changes are observed in the C and N K-edge spectra acquired during cooling, indicating that the average solvation structure around imidazole molecules does not change significantly while traversing the thermodynamically metastable supersaturated zone. To the best of our knowledge this is the first time X-ray Raman scattering has been used for studying molecular speciation in organic aqueous solutions during crystallization. Time-dependent density functional theory (TD-DFT) calculations of the near-edge spectra were performed using implicit, explicit and combined solvation models to elucidate the likely binding sites of the water molecules. An explicit solvation model with one water molecule coordinating each nitrogen moiety in the imidazole ring accurately reproduces the peak positions and intensities of the XRS spectra of aqueous imidazole solution.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2018, The Royal Society of Chemistry. This article is licensed under a Creative Commons Attribution 3.0 Unported Licence. To view a copy of this license, visit https://creativecommons.org/licenses/by/3.0/. |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Chemical & Process Engineering (Leeds) The University of Leeds > Faculty of Arts, Humanities and Cultures (Leeds) > School of Design (Leeds) |
Funding Information: | Funder Grant number Infineum Ltd PO 4500672762 Royal Academy of Engineering BRAGG Chair Diamond Light Source Ltd BRAGG Chair Astra Zeneca 8300100864 Astra Zeneca n/a EPSRC (Engineering and Physical Sciences Research Council) EP/I013563/1 EPSRC (Engineering and Physical Sciences Research Council) EP/P006965/1 |
Depositing User: | Symplectic Publications |
Date Deposited: | 06 Sep 2018 15:20 |
Last Modified: | 25 Jun 2023 21:29 |
Status: | Published |
Publisher: | Royal Society of Chemistry |
Identification Number: | 10.1039/C8CE00929E |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:135169 |