The crystal structure of WCl₆

Abstract

A WCI6 compound, isostructural with UCI6, has been identified by comparing calculated intensities with Debye-Scherrer patterns.During the examination of a commercial~ preparation of supposed WCIs, the material was submitted for X-ray analysis to verify the compound designation. Chemical analyses were inconclusive in determining the W:CI ratio because of difficulties with the reactivity of the compound. With the Debye-Scherrer techniques used, the pattern proved unidentifiable with any other tungsten-chlorine compound previously described (Reick, 1967). Other physical property measurements such as color and boiling point implied that the compound should be WCI6. The Debye-Scherrer pattern, however, did not conform to that of WCI6 described by Ketelaar & Oosterhout (1943).Needle-shaped single crystals of the unknown were examined on a Buerger precession camera. The diffraction symbol proved to be 3m P---with cell constants a0= 10.511+0.003, c0=5. for WC]6. Observed intensities are estimated visually from the DebyeScherrer pattern. The calculated intensities include an absorption correction for ~t=498 cm-1 and a 0-3-mm-dia. spindle. In space group P3ml, hk.l and kh.l are nonequivalent; however, no distinction between these reflections has been made in the assignment of indices.

An Investigation of Chlorine Ligands in Transition-Metal Complexes via 35Cl Solid-State NMR and Density Functional Theory Calculations

“…The β-form has two tungsten atoms and three chlorine atoms within the asymmetric unit. The three chlorine sites have similar W–Cl bond lengths (2.23, 2.26, and 2.34 Å) and comparable Cl–W–Cl bond angles (91.3, 91.6, and 90.3°), resulting in a slightly distorted octahedral arrangement of chlorine atoms about the central tungsten atom . Both forms feature hexagonal close packed lattices of chlorine atoms with tungsten ions filling the octahedral holes.…”

A Revised Structure Model for the UCl6 Structure Type, Novel Modifications of UCl6 and UBr5, and a Comment on the Modifications of Protactinium Pentabromides

“…Taylor and Wilson reported the structure of WCl 6 in 1974 with the correct z ‐coordinate of the W(2) atom, but seem not to have noticed the difference to the U(2) coordinate in their original report on UCl 6 . A previous report from 1968 gave the wrong z ‐coordinate . Only recently, the correct single‐crystal structure of β‐WCl 6 was published, whereas a structure refinement based on powder X‐ray data assumed WCl 6 to be isotypic to the wrong UCl 6 structure .…”

“…[28] Ap revious report from 1968 gave the wrong z-coordinate. [29] Only recently,t he correct single-crystal structureo fb-WCl 6 was published, [27] whereas as tructure refinement based on powder X-ray data assumed WCl 6 to be isotypic to the wrong UCl 6 structure. [30] We carried out aq uantumc hemical structuralo ptimization on WCl 6 starting with wrong atom coordinates for W(2) (z = 0.52, DFT-PBE0-D3/TZVP level of theory).…”

The structure of β-tungsten hexachloride by powder neutron and X-ray diffraction

“…Although a phase change at 228°C had been observed by Liempt (1931), the structure of the second polymorph of WC16 was not investigated until recently (Smith, Landingham, Smith & Johnson, 1968). These authors found a hexagonal polymorph of WC16 with a=10.511 (3) A and c=5.757 (1) A, (Table 1), the cell being similar to that of UCI6 which has the hexagonal space group P3ml and a= 10.…”

“…As a rough guide, the ratio (bw)2/(6 2 2 bc, +bw) is only 4 %, whereas in the X-ray case, the corresponding ratio is about 75%. It was therefore considered worth while to determine the parameter z-W(2) by a refinement of the X-ray powder data of Smith, Landingham, Smith & Johnson (1968).…”