Oxide halides of molybdenum and tungsten. I. Preparations

New preparations of molybdenum oxide tetrachloride, MoOCl4; tungsten oxide tetrachloride, WOCl4; molybdenum oxide trichloride, MoOCl3; molybdenum dioxide dibromide, MoO2Br2; and molybdenum oxide tribromide, MoOBr3, have been developed. It has been shown that all previous preparations of molybdenum pentachloride apparently contained some oxide tetrachloride. The magnetic susceptibility of pure molybdenum pentachloride has been measured over a temperature range.