新しい分光法で水の量子の秘密が明らかに(A new spectroscopy reveals water’s quantum secrets)

2024-10-26

2024-10-25 スイス連邦工科大学ローザンヌ校(EPFL)

EPFLのSylvie Roke教授らが開発した新しい「相関振動分光法（CVS）」により、水分子間の水素結合を直接観測し、電子および核の量子効果を測定することが初めて可能となりました。CVSは、従来の方法では区別が難しかった結合分子と非結合分子を分けて測定でき、結合強度や電荷共有の詳細を明確に把握できます。この手法は水のみならず、他の液体や溶液中の分子レベルの相互作用の解明にも応用できると期待されています。

＜関連情報＞

水の水素結合ネットワークを解明する電荷移動と核量子効果 Dissecting the hydrogen bond network of water: Charge transfer and nuclear quantum effects

Mischa Flór, David M. Wilkins, Miguel de la Puente, Damien Laage, […], and Sylvie Roke
Science Published:24 Oct 2024
DOI:https://doi.org/10.1126/science.ads4369

Abstract

The molecular structure of water is dynamic, with intermolecular (H)-bond interactions being modified by both electronic charge transfer and nuclear quantum effects (NQEs). Electronic charge transfer and NQEs potentially change under acidic / basic conditions, but such details have not been measured. Here, we developed correlated vibrational spectroscopy, a symmetry-based method that distinctively separates interacting from non-interacting molecules in self- and cross-correlation spectra, giving access to previously inaccessible information. We found that OH⁻ donated ~8% more negative charge to the H-bond network of water and H₃O⁺ accepted ~4% less negative charge from the H-bond network of water. D₂O had ~9% more H-bonds compared to H₂O, and acidic solutions displayed more dominant NQEs than basic ones.