Crystal Structures of CuCl2·2H2O (Eriochalcite) and NiCl2∙6H2O (Nickelbischofite) at Low Temperature: Full Refinement of Hydrogen Atoms Using Non-Spherical Atomic Scattering Factors

Abstract

New structure determinations of CuCl2∙2H2O and NiCl2∙6H2O are reported from 100 K X-ray diffraction experiments using both Mo Kα and Cu Kα radiation. Combined density functional theory (ORCA) and non-spherical atomic scattering factor (NoSpherA2) computations enabled Hirshfeld atom refinements (HAR) using custom atom scattering factors based on accurately polarized atom electron densities. The water hydrogen atoms could be positionally refined resulting in distinctly longer O–H bond lengths than those reported from previous X-ray diffraction experiments, but in good agreement with legacy neutron diffraction studies. Anisotropic displacement factors were employed, for the first time in these compounds by any technique. The outcomes from using the different X-ray sources with this new HAR method are compared, and the precision of the H-atom refinements evaluated where possible.

Solvatochromism of Cupric Chloride and Its Conversion to Copper Oxide

“…CuCl 2 ·2H 2 O dissolved in water, isopropanol, and acetone gives solutions visibly blue, green, and yellow-green, respectively, as shown in Figure . Boeré has recently published the single-crystal structure of CoCl 2 ·2H 2 O …”

“…In an octahedral transition metal complex with six ligands, five d orbitals of the metal ions are split into t 2g and e g levels (Figure 5). For d 9…”

Mineralogical Crystallography Volume III

“…The crystal structures of synthetic analogs of two natural transition metals-chloride hydrates eriochalcite (CuCl2•2H2O) and nickelbischofite (NiCl2•6H2O)-were described by R.T. Boeré [10] using combined density functional theory and non-spherical atomic scattering factor calculations. Compared to CuKα, the MoKα source demonstrated a 50% improvement in XRD data modeling using Hirshfeld atom refinement, both in terms of overall refinement parameters and more precise H-atom ellipsoids assignment.…”

Dispersion in Crystal Structures of 1-Chloro-3-aryl-5-trihalomethyl-1λ4,2,4,6-thiatriazines: Towards an Understanding of the Supramolecular Organization of Covalent Thiazyl Chlorides

“…Through the synthetic work reported here, which produced a systematic series of five new 1-chloro-3-aryl-5-trichloromethyl-1 4 ,2,4,6-thiatriazines, all of which were isolable as single crystals and subjected to SC-XRD, there is an unprecedented opportunity to investigate the scope of { + S•••N − } 2 interactions in this class of thiazyl chlorides. Crystal quality was overall very high and, by using Hirshfeld atom refinement (HAR) methods, [24][25][26][27][28] full refinement of the H-atom positions and anisotropic displacements was possible for these six species (including a new HAR on EZOVOV, identified henceforth as 3e), the molecular and supramolecular structures of which are the subject of this report. 19 The preparation of the compounds is outlined in Scheme 1.…”