Nicholas Thomas C, Headen Thomas F, Wasse Jonathan C, Howard Christopher A, Skipper Neal T, Seel Andrew G
Department of Chemistry, Inorganic Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QR, U.K.
ISIS Spallation Neutron and Muon Source, STFC Rutherford Appleton Laboratory, Didcot, Oxfordshire OX11 0QX, U.K.
J Phys Chem B. 2021 Jul 15;125(27):7456-7461. doi: 10.1021/acs.jpcb.1c03843. Epub 2021 Jul 2.
The local and intermediate range ordering in Ca-NH solutions in their metallic phase is determined through H/D isotopically differenced neutron diffraction in combination with empirical potential structure refinements. For both low and high relative Ca concentrations, the Ca ions are found to be octahedrally coordinated by the NH solvent, and these hexammine units are spatially correlated out to lengthscales of ∼7.4-10.3 Å depending on the concentration, leading to pronounced ordering in the bulk liquid. We further demonstrate that this liquid order can be progressively disrupted by the substitution of Ca for Na, whereby a distortion of the average ion primary solvation occurs and the intermediate range ion-ion correlations are disrupted.
通过氢/氘同位素差异中子衍射结合经验势结构精修，确定了处于金属相的钙-氨溶液中的局域和中程有序性。对于低钙和高钙相对浓度，发现钙离子由氨溶剂八面体配位，并且这些六氨络合物单元在空间上相关，其长度尺度约为7.4 - 10.3 Å，具体取决于浓度，从而导致本体液体中出现明显的有序性。我们进一步证明，通过用钠替代钙，这种液体有序性会逐渐被破坏，由此平均离子一级溶剂化发生畸变，中程离子-离子相关性被破坏。
