Orientation and dynamics of water molecules in beryl

0575359 - FZÚ 2024 RIV US eng J - Journal Article
Chlan, V. - Adamec, Martin - Štěpánková, H. - Thomas, V.G. - Kadlec, Filip
Orientation and dynamics of water molecules in beryl.
Journal of Chemical Physics. Roč. 158, č. 12 (2023), č. článku 124308. ISSN 0021-9606. E-ISSN 1089-7690
R&D Projects: GA ČR(CZ) GA20-01527S; GA MŠMT(CZ) EF16_019/0000760
Grant - others:OP VVV - SOLID21(XE) CZ.02.1.01/0.0/0.0/16_019/0000760
Institutional support: RVO:68378271
Keywords : NMR spectroscopy * beryl * water molecules * dynamical behavior
OECD category: Condensed matter physics (including formerly solid state physics, supercond.)
Impact factor: 4.4, year: 2022
Method of publishing: Open access

Behavior of individual molecules of normal and heavy water in beryl single crystals was studied by 1 H and 2H nuclear magnetic resonance spectroscopy. From temperature dependences of the spectra, we deduce that type-I water molecules embedded in the beryl voids are oriented quite differently from the view established in the literature: Different from the earlier assumptions, their H–H lines deviate by about 18 degrees from the hexagonal axis. We suggest that this is due to the molecules attaching to the oxygen atoms forming the beryl structural voids by a hydrogen bond. Our analysis shows that the molecules perform two types of movement: (i) rapid librations around the axis of the hydrogen bond and (ii) less frequent orientational jumps among the 12 possible binding sites in the beryl voids. The frequencies of the librational motions are evaluated from a simple thermodynamic model, providing good agreement with the frequencies of librations from optical experiments reported earlier.

Permanent Link: https://hdl.handle.net/11104/0345146