Temperature-induced mobility in octacalcium phosphate impacts crystal symmetry: water dynamics studied by NMR crystallography.

Autor: Nelson A; LCMCP, UMR 7574, Sorbonne Université, CNRS, Paris, France. christel.gervais_stary@sorbonne-universite.fr.; ICGM, Univ Montpellier, CNRS, ENSCM, Montpellier, France. danielle.laurencin@umontpellier.fr., Papawassiliou W; IRIG, MEM, Univ. Grenoble Alpes, CEA, CNRS, 38000 Grenoble, France., Paul S; IRIG, MEM, Univ. Grenoble Alpes, CEA, CNRS, 38000 Grenoble, France., Hediger S; IRIG, MEM, Univ. Grenoble Alpes, CEA, CNRS, 38000 Grenoble, France., Hung I; National High Magnetic Laboratory (NHMFL), Tallahassee, Florida, USA., Gan Z; National High Magnetic Laboratory (NHMFL), Tallahassee, Florida, USA., Venkatesh A; National High Magnetic Laboratory (NHMFL), Tallahassee, Florida, USA., Franks WTT; Department of Physics, University of Warwick, Coventry, CV4 7AL, UK., Smith ME; Department of Physics, University of Warwick, Coventry, CV4 7AL, UK.; Department of Chemistry, University of Southampton, SO17 1BJ, UK., Gajan D; CRMN Lyon, UMR 5082, CNRS, ENS Lyon, Université Lyon 1, Villeurbanne, France., De Paëpe G; IRIG, MEM, Univ. Grenoble Alpes, CEA, CNRS, 38000 Grenoble, France., Bonhomme C; LCMCP, UMR 7574, Sorbonne Université, CNRS, Paris, France. christel.gervais_stary@sorbonne-universite.fr., Laurencin D; ICGM, Univ Montpellier, CNRS, ENSCM, Montpellier, France. danielle.laurencin@umontpellier.fr., Gervais C; LCMCP, UMR 7574, Sorbonne Université, CNRS, Paris, France. christel.gervais_stary@sorbonne-universite.fr.
Jazyk: angličtina
Zdroj: Faraday discussions [Faraday Discuss] 2024 Oct 11. Date of Electronic Publication: 2024 Oct 11.
DOI: 10.1039/d4fd00108g
Abstrakt: Octacalcium phosphate (OCP, Ca 8 (PO 4 ) 4 (HPO 4 ) 2 ·5H 2 O) is a notable calcium phosphate due to its biocompatibility, making it a widely studied material for bone substitution. It is known to be a precursor of bone mineral, but its role in biomineralisation remains unclear. While the structure of OCP has been the subject of thorough investigations (including using Rietveld refinements of X-ray diffraction data, and NMR crystallography studies), important questions regarding the symmetry and H-bonding network in the material remain. In this study, it is shown that OCP undergoes a lowering of symmetry below 200 K, evidenced by 1 H, 17 O, 31 P and 43 Ca solid-state NMR experiments. Using ab initio molecular-dynamics (MD) simulations and gauge including projected augmented wave (GIPAW) DFT calculations of NMR parameters, the presence of rapid motions of the water molecules in the crystal cell at room temperature is proved. This information leads to an improved description of the OCP structure at both low and ambient temperatures, and helps explain long-standing issues of symmetry. Remaining challenges related to the understanding of the structure of OCP are then discussed.
Databáze: MEDLINE
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