Zirconium difluoride

Zirconium difluoride [7783-49-5], Zrp2, has been isolated in rare gas—solid matrices (1). Zrp2, prepared by Knudsen ceU techniques, is not commercially available. 

Bis(7r-cyclopentadienyl)zirconium dichloride treated with chlorine in carbon tetrachloride yields Cp2(C5H5Cl2)ZrCl2 and Cp(05H5Cl4)ZrCl2, while bis(7T-cyclopentadienyl)zirconium difluoride and bromine also in carbon tetrachloride yield Cp(C5H5Br4)ZrF2 288). 

ZnF2[gl ZINC FLUORIDE (GAS) 1834 ZrF2 ZIRCONIUM DIFLUORIDE 1867... 

Znl2 ZINC IODIDE 1834 ZrF2[g] ZIRCONIUM DIFLUORIDE (GAS) 1868... 

Kroll process, 13 84-85 15 337 17 140 in titanium manufacture, 24 851-853 Kroll zirconium reduction process, 26 631 KRW gasifier, 6 797-798, 828 Krypton (Kr), 17 344 commercial, 17 368t complex salts of, 17 333-334 doubly ionized, 14 685 hydroquinone clathrate of, 14 183 in light sources, 17 371-372 from nuclear power plants, 17 362 physical properties of, 17 350 Krypton-85, 17 375, 376 Krypton compounds, 17 333-334 Krypton derivatives, 17 334 Krypton difluoride, 17 333, 336 uses for, 17 336... 

Safety precautions applicable to direct liquid phase fluorination of aromatic compounds are discussed [1]. Attention is drawn to the hazards attached to the use of many newer fluorinating agents [2], In a study of fluorination reactions of hafnium and zirconium oxides by the fluoroxidisers xenon difluoride, chlorine trifluoride and bromine trifluoride, reactivity decreased in the order given [3],... 

Uranium can be analysed as the hexafluoride, but the procedure requires modification of the chromatographic apparatus, nickel coating of metallic parts and nickel filaments in the katharometer [606], Tin in zirconium—tin alloys can be analysed as the chloride, prepared by treatment with chlorine [607]. Selenium and tellurium are converted into fluorides by treatment of their oxides with xenon difluoride [608]. 

As exemplified by the reactions of Schemes 1 and 4, fluorotitanium compounds could open new possibilities for metal-catalyzed processes. Their fascinating structural diversity [7] as well as further catalytic possibilities in the field of olefin polymerizations [7i, 16] have been put forward by the pioneering work of Roesky, Noltemeyer and co-workers. Similar properties were also exhibited by the analogous zirconium and hafnium compounds [7b,i]. A Zr binaphtholate has already been successfully applied for the enantioselective allylstannylation of aldehydes [2f], Buch-wald and co-workers successfully used a chiral titanocene difluoride as precursor for the corresponding Ti(lII) hydride, a very efficient catalyst for the enantioselective hydrosilylation of imines [17]. 

Infrared spectra of 1 1 adducts of xenon difluoride with molybdenum and tungsten hexafluorides and 2 1 adducts with tin, zirconium and hafnium tetrafluorides have been assigned on the basis of their containing [XeF]+ cations [XeF]+[MF6]2-(M = Ti, Zr, Hf) 84-85>. This is supported in the case of 2 XeF2 SnF4 by Mossbauer work 86). Data on nXeF2 TiF4 (n = 1.5, 1 and 0.5) are less well defined 87). 

Arylamido complexes of a general formula of Cp Zr[N(Ar)SiMe3]Cl2 can be obtained in a similar fashion. Thus, the reaction of Cp MCl3 with 1 equiv. of Li[N(Ar)SiMe3] produces complexes 31248 and 313.252 The difluoride 312 was prepared by metathesis reaction of the dichloride and Me3SnF. Upon activation with MAO, all complexes are active for polymerization of ethylene within complexes 312, the zirconium complexes are much more active than the analogous hafnium complexes, whereas within complexes 313, the zirconium complex exhibits poor activity as compared with the analogous titanium complex. 

TETRACHLORO ZIRCONIUM (10026-11-6) Decomposes in the presence of moist air, forming a dense white cloud and hydrogen chloride fumes may ignite spontaneously. Reacts with water, steam, releasing heat, a dense white cloud, and hydrogen chloride. Violent reaction with bromine pentafluoride, lithium, oxygen difluoride, tetrahydrofuran. Contact... 

ZIRCAT (7440-67-7) Finely divided material is spontaneously flammable in air may ignite and continue to bum under water. Violent reactions with oxidizers, alkali hydroxides, alkali metals (and their compounds), carbon tetrachloride, cupric oxide, lead, lead oxide, lead peroxide (combined material can burn explosively, and is sensitive to friction and static electricity), nitryl fluoride, oxygen difluoride, phosphoms, potassium, potassium compounds (potassium chlorate, potassium nitrate), sodium borate, sodium hydroxide. Explodes if mixed with hydrated borax when heated. Contact with lithium chromate may cause explosion above 752°F/450°C. Forms explosive mixture with potassium chlorate. Dusts of zirconium ignite and explode in a carbon dioxide atmosphere. Contact with ammonium-V-nitrosophenylhydroxylamine above 104°F/40°C forms an explosive material. Incompatible with boron, carbon, nitrogen, halogens, lead, platinum, potassium nitrate. In case of fire, use approved Class D extinguishers or smothering quantities of dry sand, crushed limestone, clay. 

Dihalides of uncertain purity are prepared by the disproportionation of the trihalides. Alternate routes have also been reported. Swaroop and Flengas (549) prepared ZrCU of 95-99% purity by heating the trichloride and metallic zirconium at 675°C for 30-35 hours in an evacuated quartz tube lined with platinum foil. There is also a reference to the production of liquid dihalides by the reaction of the gaseous tetrahalides with loosely packed zirconium at 700°C for the chloride and 400°C for the bromide and iodide (270). The difluoride has been prepared (357) by the reaction of atomic hydrogen on thin layers of zirconium tetrafluoride at 350°C. New data on hafnium are lacking, although Corbett (542) has concluded that hafnium diiodide does not exist. 

The reactions of perfluoro-(l-methylpropenyl)silver with chromium-(p. 292), manganese- and rhenium- (p. 298), iron- (p. 303), and cobalt-halogen compounds (p. 318), and its redox reactions with the decacarbonyl-dimetallate ions [Ma(CO)i ] (M = Cr, Mo, or W) (p. 292), have already been described. With di(7r-Qrclopentadienyl)-titanium and -zirconium dichlorides, however, only the corresponding difluorides (w-C5H )aMFa (M = Ti or 7jl) are obtained. ... 

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