Van't Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands.
Department of Chemistry, Oklahoma State University, Stillwater, Oklahoma 74078, USA.
J Chem Phys. 2018 Jun 21;148(23):234501. doi: 10.1063/1.5029908.
The catalytic action of NH within the all-vapor approach for instant clathrate hydrate (CH) formation is studied using both FTIR spectroscopy and ab initio molecular dynamics simulations. A unique property of NH, namely, the rapid abundant penetration and occupation of the water network, creates defects, particularly Bjerrum D-defects, in the hydrate frame that are generally stabilized by guest NH molecules in the cages. Furthermore, insertion of NH seriously disturbs the hydrate network where the guest NH molecules also make fluxional H-bonds with the host water molecules. These defects strongly facilitate a sub-second formation of the simple NH s-II gas hydrate at 160 K. FTIR spectra of aerosols of the NH s-II CH have been measured, and the displacement of both small and large cage NH guests by CO and tetrahydrofuran is examined.
利用傅里叶变换红外光谱和从头算分子动力学模拟研究了全蒸汽法中 NH 的催化作用对瞬间笼形水合物（CH）形成的影响。NH 的一个独特性质是其快速且丰富地渗透和占据水网络，从而在水合物框架中产生缺陷，特别是 Bjerrum D 缺陷，这些缺陷通常由笼中的客体 NH 分子稳定。此外，NH 的插入严重干扰了水合物网络，其中客体 NH 分子也与主体水分子形成动态氢键。这些缺陷强烈促进了在 160 K 下简单 NH s-II 气体水合物的亚秒级形成。已经测量了 NH s-II CH 气溶胶的傅里叶变换红外光谱，并研究了 CO 和四氢呋喃对小笼和大笼 NH 客体的取代。
