Crystal data for tachyhydrite, CaMg₂Cl₆.12H₂O

Abstract

Synthetic crystals of tachyhydrite are trigonal, diffraction aspect R**, with hexagonal parameters a = 10.136 (1), c = 17.318 (2) Å, U = 1540.9 (3) Å3, Z = 3, Dc = 1.673 Mg m−3. Indexed powder data are given.

Tachyhydrite, dimagnesium calcium chloride 12-hydrate

“…The final positional accuracy of the atoms is 0.002/k for Ca, Mg and C1, 0.003 A for O, and 0.1 /k for H. The final structural and thermal parameters are given in Table 1. X-ray powder data for tachyhydrite published by Erd et al (1979), have been found to agree reasonably well with corresponding data calculated from the structure reported here. * Discussion.…”

“…The standard errors given by Leclaire et al, are generally less than ours, and the hydrogen atoms are somewhat better resolved. We believe, however, that in the case of the unit-cell parameters, where the differences are more substantial, the results of Erd et al (1979), obtained from a calibrated powder diffractometer pattern made with Cu Ka radiation, are more reliable.…”

“…Tachyhydrite appeared to be of interest because of its occurrence in evaporite deposits, its high water content, and its unusually wide stability field (in equilibrium with mother liquor) over temperatures from 295 K to at least 440 K (van't Hoff & Kenrick, 1897). Data on its synthesis, crystallography, and powder pattern were reported by Erd, Clynne, Clark & Potter (1979). The synthetic crystal selected for collection of intensity data was an approximately spherical fragment, about 0.3 mm in diameter.…”

Woody species: a new bio-based material for dual Ca/Mg catalysis with remarkable Lewis acidity properties

“…The salt was quickly crushed with a mortar and stored in an anhydrous environment. The procedure described by Erd et al 70 led us to obtain CaMg2Cl6 salt. Dry CaCl2 (200 mg, 1.8 mmol) and dry MgCl2 (240 mg, 2.52 mmol) were dissolved in 560 µL of pure water.…”

Phytoextracted mining wastes for ecocatalysis: Eco-Mn®, an efficient and eco-friendly plant-based catalyst for reductive amination of ketones

“…This extremely hygroscopic character may be attributed to CaMg 2 Cl 6 (H 2 O) 12 which is described in those terms in several papers. 91 As Eco-Mn® did not display such properties and can be manipulated without an anhydrous atmosphere, its stability may be due to the particular structure of its constituents or to other species not identified yet. This was confirmed by a test with a "reconstituted" Eco-Mn®, prepared by mixing commercial chlorides of K, Mg, Ca, Al, Mn, Fe and Ni, in the same proportions as in Eco-Mn®, following its ICP-MS analysis (Table 1).…”