Zirconium tetrabromide

Zirconium tetrabromide [13777-25-8] ZrBr, is prepared direcdy from the elements or by the reaction of bromine on a mixture of zirconium oxide and carbon. It may also be made by halogen exchange between the tetrachloride and aluminum bromide. The physical properties are given in Table 7. The chemical behavior is similar to that of the tetrachloride. 

Zirconium silicate crystals, 19 405 Zirconium-silicon alloy, 22 520-521 Zirconium tetrabromide, 26 645 Zirconium tetrachloride, 26 629, 630—631,... 

Zirconium tetrabromide is a white microcrystalline salt which is very hygroscopic. It dissolves in water with the liberation of heat, forming zirconyl bromide. The tetrabromide is also soluble in certain organic solvents, such as alcohol and ether. It reacts with ammonia at low temperature to form ammines. 

The zirconium tetrahalides react with esters to form ZrX4 2 ester adducts (302, 303, 330, 407-410, 412) in which, coordination number six is attained. On the basis of dipole moments (Table XIII), it is concluded that the adducts have the cis structure. This has been supported, at least in the case of ZrCl4 2011300 0 02115, by the infrared spectrum (330). Oryoscopic studies in benzene solution of the 2 1 adducts of zirconium tetrachloride and ethyl formate, ethyl acetate, and ethyl butryrate show that these complexes tend to decompose to the 1 1 species, the extent of dissociation increasing with the number of carbon atoms in the acid radical. The estimated dissociation constant is about 5 x 10", whereas for the ethyl acetate adduct of zirconium tetrabromide it is only 2 X 10". The approximate dissociation constant of the complex zirconium tetraiodide 2 ethyl acetate is 3.5 x 10". The 1 1 species were synthesized by direct reaction in benzene with strictly stoichiometric ratios of the reactants. Oryoscopic determination of molecular weights of the 1 1 complexes indicate that these complexes generally... 

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). 

Yb203 DIYTTERBIUM TRIOXIDE 1826 ZrBr4 ZIRCONIUM TETRABROMIDE 1858... 

The sublimation of solid zirconium tetrabromide to gaseous ZrBr4, as represented by Eq.(V.56) ... 

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. 

---