Li Weixing, Pérez Cristóbal, Steber Amanda L, Schnell Melanie, Lv Dingding, Wang Guanjun, Zeng Xiaoqing, Zhou Mingfei
Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Songhu Rd. 2005, 200438 Shanghai, China.
Deutsches Elektronen-Synchrotron DESY, Notkestraße 85, 22607 Hamburg, Germany.
J Am Chem Soc. 2023 Feb 10. doi: 10.1021/jacs.2c11732.
The investigation on the preferred arrangement and intermolecular interactions of gas phase solute-water clusters gives insights into the intermolecular potentials that govern the structure and dynamics of the aqueous solutions. Here, we report the investigation of hydrated coordination networks of benzaldehyde-(water) ( = 1-6) clusters in a pulsed supersonic expansion using broadband rotational spectroscopy. Benzaldehyde (PhCHO) is the simplest aromatic aldehyde that involves both hydrophilic (CHO) and hydrophobic (phenyl ring) functional groups, which can mimic molecules of biological significance. For the = 1-3 clusters, the water molecules are connected around the hydrophilic CHO moiety of benzaldehyde through a strong CO···HO hydrogen bond and weak CH···OH hydrogen bond(s). For the larger clusters, the spectra are consistent with the structures in which the water clusters are coordinated on the surface of PhCHO with both the hydrophilic CHO and hydrophobic phenyl ring groups being involved in the bonding interactions. The presence of benzaldehyde does not strongly interfere with the cyclic water tetramer and pentamer, which retain the same structure as in the pure water cluster. The book isomer instead of cage or prism isomers of the water hexamer is incorporated into the microsolvated cluster. The PhCHO molecule deviates from the planar structure upon sequential addition of water molecules. The PhCHO-(HO) clusters may serve as a simple model system in understanding the solute-water interactions of biologically relevant molecules in an aqueous environment.
对气相溶质 - 水团簇的优选排列和分子间相互作用的研究有助于深入了解控制水溶液结构和动力学的分子间势。在此，我们报告了使用宽带转动光谱对脉冲超声速膨胀中苯甲醛 -（水）(n)（(n = 1 - 6)）团簇的水合配位网络的研究。苯甲醛（PhCHO）是最简单的芳香醛，兼具亲水性（CHO）和疏水性（苯环）官能团，可模拟具有生物学意义的分子。对于(n = 1 - 3)的团簇，水分子通过强CO···HO氢键和弱CH···OH氢键围绕苯甲醛的亲水性CHO部分相连。对于较大的团簇，光谱与水团簇在PhCHO表面配位的结构一致，亲水性CHO和疏水性苯环基团均参与键合相互作用。苯甲醛的存在不会强烈干扰环状水四聚体和五聚体，它们保持与纯水团簇相同的结构。水六聚体的书页异构体而非笼状或棱柱状异构体被纳入微溶剂化团簇。随着水分子的依次添加，PhCHO分子偏离平面结构。PhCHO -（(H_2O)）(n)团簇可作为一个简单的模型系统，用于理解水性环境中生物相关分子的溶质 - 水相互作用。
