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      On the influence of water on THz vibrational spectral features of molecular crystals

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          Abstract

          Phase transformation under dehydration of α-lactose monohydrate, experimentally followed with TeraHertz spectroscopy and analyzed by periodic DFT computations.

          Abstract

          The nanoscale structure of molecular assemblies plays a major role in many (μ)-biological mechanisms. Molecular crystals are one of the most simple of these assemblies and are widely used in a variety of applications from pharmaceuticals and agrochemicals, to nutraceuticals and cosmetics. The collective vibrations in such molecular crystals can be probed using terahertz spectroscopy, providing unique characteristic spectral fingerprints. However, the association of the spectral features to the crystal conformation, crystal phase and its environment is a difficult task. We present a combined computational–experimental study on the incorporation of water in lactose molecular crystals, and show how simulations can be used to associate spectral features in the THz region to crystal conformations and phases. Using periodic DFT simulations of lactose molecular crystals, the role of water in the observed lactose THz spectrum is clarified, presenting both direct and indirect contributions. A specific experimental setup is built to allow the controlled heating and corresponding dehydration of the sample, providing the monitoring of the crystal phase transformation dynamics. Besides the observation that lactose phases and phase transformation appear to be more complex than previously thought – including several crystal forms in a single phase and a non-negligible water content in the so-called anhydrous phase – we draw two main conclusions from this study. Firstly, THz modes are spread over more than one molecule and require periodic computation rather than a gas-phase one. Secondly, hydration water does not only play a perturbative role but also participates in the facilitation of the THz vibrations.

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          Most cited references104

          • Record: found
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          • Article: not found

          Generalized Gradient Approximation Made Simple

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            • Record: found
            • Abstract: not found
            • Article: not found

            Projector augmented-wave method

            P. Blöchl (1994)
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              • Record: found
              • Abstract: found
              • Article: not found

              From ultrasoft pseudopotentials to the projector augmented-wave method

              Physical Review B, 59(3), 1758-1775
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                Author and article information

                Contributors
                (View ORCID Profile)
                (View ORCID Profile)
                Journal
                PPCPFQ
                Physical Chemistry Chemical Physics
                Phys. Chem. Chem. Phys.
                Royal Society of Chemistry (RSC)
                1463-9076
                1463-9084
                March 09 2022
                2022
                : 24
                : 10
                : 6107-6125
                Affiliations
                [1 ]Institut d’Electronique de Microélectronique et de Nanotechnologie, Université Lille, CNRS, 59652 Villeneuve d’Ascq, France
                [2 ]IMO, Hasselt University, 3590 Diepenbeek, Belgium./AMIBM, Maastricht University, 6167 Geleen, The Netherlands
                [3 ]Univ. Lille, CNRS, UMR 8576 – UGSF – Unité de Glycobiologie Structurale et Fonctionnelle, F-59000 Lille, France
                Article
                10.1039/D1CP03261E
                a34b7dae-0ad9-489b-a654-0d5556d20b0b
                © 2022

                http://rsc.li/journals-terms-of-use

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