X-N Charge Density and Isotope Effects in the Low-Barrier N-H N Hydrogen Bonds in H3Co(CN)6 and D3Co(CN)6

Our goal with this project is to gain insight into the bonding mechanisms of low barrier N-H…N hydrogen bonds and how increased thermal energy changes the charge density distribution of these strong hydrogen bonds. Furthermore we wish to study how the isotope effect manifests itself in the charge density.To study the charge density one need highly accurate and high resolution X-ray diffraction data. However, in this case due to the weak X-ray scattering power of hydrogen/deuterium, neutron data is needed to describe the position and thermal motion of H/D. Both X-ray and neutron diffraction data is combined in one refinement, a so-called X-N charge density refinement. We already have collected high resolution and high quality X-ray data and therefore, we ask for beam time to complete the neutron diffraction experiments.本项目的研究目标为深入阐明低势垒N-H…N氢键的成键机制，以及热能量提升如何改变这类强氢键的电荷密度分布。此外，本研究拟探究同位素效应在电荷密度中的具体表现。要开展电荷密度研究，需依托高精度、高分辨率的X射线衍射（X-ray diffraction）数据。但鉴于氢/氘的X射线散射能力较弱，需借助中子数据来描述H/D的位置与热运动特性。我们将X射线与中子衍射数据结合进行单一精修，即所谓的X-N电荷密度精修（X-N charge density refinement）。目前我方已采集得到高分辨率、高质量的X射线数据，因此申请束流时间以完成全部中子衍射实验。