Crystal chemical studies of the 5f-series of elements. II. The crystal structure of Cs2PuCl6

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

“…Using the correct z ‐coordinate for the U(2) atom, the coordinates of all the Cl atoms are affected and an R all value of about 0.06 is obtained. In comparison, using and refining the coordinates from the literature, the refinement converges to an R all value of about 0.10. Taylor and Wilson reported that the coordination octahedron around the U(1) atom was nearly regular, whereas the one around the U(2) atom was slightly distorted.…”

“…Uranium hexachloride is a black powder with a slight green luster. Due to the difficulty in obtaining single crystals of UCl 6 , its crystal structure was previously determined “only” from microcrystalline samples using either powder X‐ray or powder neutron diffraction . The proposed structure model led to rather differing U−Cl bond lengths within one of the two crystallographically distinct UCl 6 molecules.…”

Phase Separation of LaI3 inside Single‐Walled Carbon Nanotubes

“…The well‐resolved lower part of the LaI x @(18,3)SWNT encapsulation composite is given in Figure 3 a, where the white lines mark single‐pixel line profiles, obtained from the alternating three‐membered rows of the filling material. The observed variation of the phase contrast was compared to that of an equivalently sized fragment, extracted from the crystallographic data of bulk LaI 3 , as used in the synthesis of the encapsulation composite 8. The stepwise modelling process is given in Figure 4: Figures 4 a and 4 b, respectively, show the extraction of the LaI 3 fragment and the conduction of a clockwise rotation of the latter by 26° (i.e., around the bulk crystal's y axis identical to the image plane) in order to match the average measured distance of 0.34 Å between neighbouring bright dots of both three‐membered rows (see line profiles in Figure 3 a).…”

“…The stepwise modelling process is given in Figure 4: Figures 4 a and 4 b, respectively, show the extraction of the LaI 3 fragment and the conduction of a clockwise rotation of the latter by 26° (i.e., around the bulk crystal's y axis identical to the image plane) in order to match the average measured distance of 0.34 Å between neighbouring bright dots of both three‐membered rows (see line profiles in Figure 3 a). This distance corresponds to the maximum LaI bond length of bulk LaI 3 (0.339 Å), and the selected fragment had to be rotated by 26°, in order to achieve a projection perpendicular to these bonds 8. Figure 4 b furthermore illustrates the elimination of all divalent iodine atoms (I2), indicated by the unfilled crosses.…”

“…The end‐on views of the LaI 3 @(18,3)SWNT model illustrate the elimination of divalent iodine atoms (black crosses). 8…”