Hafnium tetrabromide

Hafnium tetrabromide [13777-22-5], HfBr, is very similar to the tetrachloride in both its physical and chemical properties. Hafnium tetraiodide [13777-23-6], Hfl, is produced by reaction of iodine with hafnium metal at 300°C or higher. At temperatures above 1200°C, the iodide dissociates to hafnium metal and iodine. These two reactions are the basis for the iodide-bar refining process. Hafnium iodide is reported to have three stable crystalline forms at 263—405°C (60). 

Hafnium metal, analysis of, 13 87 Hafnium nitride, 13 89—90, 93 Hafnium oxide, 13 89, 93—94 reduction of, 73 84 Hafnium sulfides, 73 94 Hafnium tetrabromide, 73 93 Hafnium tetrachloride, 73 92 26 631 vapor reduction of, 73 84-85 Hafnium tetrafluoride, 73 90, 91 Hafnium tetrahydridoborate, 73 90 Hagen-Poiseuille expression/law, 27 726, 729 Hagen-Poiseuille flow, in microfluidics, 26 961... 

Klemn also reported that zirconium tetrabromide possessed a structure similar to the iodide but with tetragonal distortion. Berdonosov and co-workers (58), apparently unaware of Klemn s report, write that zirconium tetrabromide has a primitive cubic lattice with a= 10.95 0.01 A, and assigned the space group T, by analogy with zirconinm tetrachloride. Zirconium and hafnium tetrabromides seem to be structurally different than titanium tetrabromide. It is observed that titanium tetrabromide is soluble to the extent of 40% in chloroform and 30% in ethylene dichloride and carbon tetrachloride, whereas zirconium and hafnium tetrabromides are soluble to the extent of only 4% in chloroform and 0% in carbon tetrachloride (57). 

BER/TSI] Berdonosov, S. S., Tsirel nikov, V. I., Lapitskii, A. V., Density and pressure of saturated vapors of zirconium and hafnium tetrabromides, Vestn. Mask. Univ. Ser. 2 Khim., 20, (1965), 26-29. Cited on page 177. 

CAR/SMI] Carter, J. C., Smith, J. A. S., Nuclear quadrupole resonance in hafnium and zirconium tetrabromide, J. Chem. Soc. Chem. Commun., 20, (1974), 835-836. Cited on page 172. 

RJH Clark, BK Hunter, DM Rippon. Vapor-phase Raman spectra, force constants, and values for thermodynamic functions of the tetrachlorides, tetrabromides, and tetraiodides of titanium, zirconium, and hafnium. Inorg Chem 11 56-61, 1972. 

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