MoF6 MOLYBDENUM FLUORIDE

MoF6 MOLYBDENUM FLUORIDE 41.680 4.1131E-01 -6.0261E-04 4.0311E-07 -1.0025E-10 298 1500 gas... 

Molybdenum Fluoride or Molybdenum Hexafluoride, MoF6, mw 209.95, wh. crysts melting at 17.5° sp gr of liq about 2.5 bp 35° reacts readily with w. Can be prepd by direct action of fluorine on Mo metal. Used in die separation of Mo isotopes... 

Tungsten(VI) fluoride (WF6) and molybdenum(VI) fluoride (MoF6) are available commercially, and can be made by reaction of the metals with fluorine.4 In the case of uranium(VI) fluoride (UF6), a preparation that is claimed5 to be feasible in the laboratory uses uranium metal and chlorine trifluoride uranium(VI) fluoride is prepared6 commercially by the fluorination of uranium(IV) fluoride, itself prepared from an oxide and hydrogen fluoride. 

MoF6—The direct reaction of molybdenum with fluorine initiated around 100°C. in a copper tube -7 is specific for this highest fluoride. The method is relatively inconvenient in most laboratories because of experimental difficulties and hazards associated with the handling of elemental fluorine. A more recent procedure, which avoids elemental F2, involves the reaction between Mo03 and SF4 in a bomb at 350°C. Sulfur tetrafluoride, although expensive, is commercially available in cylinders. 

MoFj—Molybdenum(VI) fluoride can be reduced to MoF6 by PF3, Mo(CO) ,9 or molybdenum powder.9 The preferred reducing agent appears to be phosphorus(III) fluoride at room temperature because of the ease of removal of both the volatile by-product PF8 (b.p. — 85°C.) and the excess PF3 (b.p. — 102°C.). 

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