Li Weixing, Quesada-Moreno María Mar, Pinacho Pablo, Schnell Melanie
Deutsches Elektronen-Synchrotron, Notkestrasse 85, 22607, Hamburg, Germany.
Christian-Albrechts-Universität zu Kiel, Institute of Physical Chemistry, Max-Eyth-Str. 1, 24118, Kiel, Germany.
Angew Chem Int Ed Engl. 2021 Mar 1;60(10):5323-5330. doi: 10.1002/anie.202013899. Epub 2021 Jan 25.
Examined here are the structures of complexes of benzophenone microsolvated with up to three water molecules by using broadband rotational spectroscopy and the cold conditions of a molecular jet. The analysis shows that the water molecules dock sideways on benzophenone for the water monomer and dimer moieties, and they move above one of the aromatic rings when the water cluster grows to the trimer. The rotational spectra shows that the water trimer moiety in the complex adopts an open-loop arrangement. Ab initio calculations face a dilemma of identifying the global minimum between the open loop and the closed loop, which is only solved when zero-point vibrational energy correction is applied. An OH⋅⋅⋅π bond and a Bürgi-Dunitz interaction between benzophenone and the water trimer are present in the cluster. This work shows the subtle balance between water-water and water-solute interactions when the solute molecule offers several different anchor sites for water molecules.
本文利用宽带转动光谱和分子束的低温条件，研究了二苯甲酮与多达三个水分子形成的微溶剂化配合物的结构。分析表明，对于水单体和二聚体部分，水分子以侧向方式停靠在二苯甲酮上，而当水簇增长到三聚体时，它们会移动到其中一个芳环上方。转动光谱表明，配合物中的水三聚体部分采用开环排列。从头算面临着在开环和闭环之间确定全局最小值的困境，只有在应用零点振动能校正时才能解决这一困境。该簇中存在二苯甲酮与水三聚体之间的OH⋅⋅⋅π键和 Bürgi-Dunitz相互作用。这项工作表明，当溶质分子为水分子提供几个不同的锚定位点时，水-水和水-溶质相互作用之间存在微妙的平衡。
