Juanes Marcos, Saragi Rizalina Tama, Pinacho Ruth, Rubio José E, Lesarri Alberto
Departamento de Química Física y Química Inorgánica and I.U. CINQUIMA, Facultad de Ciencias, Universidad de Valladolid, Paseo de Belén, 7, 47011 Valladolid, Spain.
Departamento de Electrónica, Escuela de Ingeniería de Telecomunicaciones, Universidad de Valladolid, Paseo de Belén, 15, 47011 Valladolid, Spain.
Phys Chem Chem Phys. 2020 Jun 10;22(22):12412-12421. doi: 10.1039/d0cp01706j.
The monohydrates of thenyl alcohol and thenyl mercaptan have been probed in a supersonic jet expansion using chirped-pulse and Fabry-Perot Fourier-transform microwave spectroscopy. The rotational spectra revealed a single isomer for each of the dimers. The thenyl alcohol hydrate is stabilized by an O-HOw hydrogen bond between the alcohol and water, with water acting as a proton acceptor and additionally engaging in an Ow-Hπ interaction with the thenyl ring. Conversely, water behaves as a proton donor in the thenyl mercaptan hydrate, linking to the thiol group though an Ow-HS hydrogen bond and secondary Ow-Hπ interactions with the ring. In both dimers water retains internal mobility, as tunneling doublings in the spectrum confirm an internal rotation motion of water inside the cluster. The experimental results have been complemented with density-functional-theory molecular orbital calculations, binding energy decomposition and a topological analysis of the electronic density, providing a comparative description of the effects of hydrogen bonding of water to the alcohol and thiol groups in the dimers, relevant to understand hydrogen bonding to sulfur centers.
使用啁啾脉冲和法布里-珀罗傅里叶变换微波光谱技术，在超声速射流膨胀中对噻吩甲醇和噻吩硫醇的一水合物进行了探测。转动光谱显示每个二聚体都只有一种异构体。噻吩甲醇水合物通过醇与水之间的O-HOw氢键得以稳定，其中水作为质子受体，此外还与噻吩环存在Ow-Hπ相互作用。相反，在噻吩硫醇水合物中，水作为质子供体，通过Ow-HS氢键与硫醇基团相连，并与环存在次级Ow-Hπ相互作用。在这两种二聚体中，水都保持内部流动性，因为光谱中的隧道分裂证实了簇内水的内部旋转运动。实验结果得到了密度泛函理论分子轨道计算、结合能分解以及电子密度拓扑分析的补充，对二聚体中氢键作用于醇和硫醇基团的水所产生的影响进行了比较描述，这对于理解与硫中心的氢键作用具有重要意义。
