Zirconium tetrachloride revisited

摘要

Zirconium tetrachloride, ZrCl 4 , is a strategic material with wide‐ranging applications. Until now, only one crystallographic study on ZrCl 4 has been reported [Krebs (1970). Z. Anorg. Allg. Chem. 378 , 263–272] and that was more than 40 years ago. The compound used for the previous determination was prepared from ZrO 2 and Cl 2 –CCl 4 , and single‐crystal X‐ray diffraction (SCXRD) studies on ZrCl 4 obtained from Zr metal have not yet been reported. In this context, we prepared ZrCl 4 from the reaction of Zr metal and Cl 2 gas in a sealed tube and investigated its structure at 100, 150, 200, 250, and 300?K. At 300?K, the SCXRD analysis indicates that ZrCl 4 crystallizes in the orthorhombic space group Pca 2 1 [ a = 6.262?(9), b = 7.402?(11), c = 12.039?(17)??, and V = 558.0?(14)?? 3 ] and consists of infinite zigzag chains of edge‐sharing ZrCl 6 octahedra. This chain motif is similar to that observed previously in ZrCl 4 , but the structural parameters and space group differ. In the temperature range 100–300?K, no phase transformation was identified, while elongation of intra‐chain Zr…Zr [3.950?(1)?? at 100?K and 3.968?(5)?? at 300?K] and inter‐chain Cl…Cl [3.630?(3)?? at 100?K and 3.687?(9)?? at 300?K] distances occurred.