Molybdenum pentachloride catalyst

Molybdenum pentachloride is used as a catalyst in chlorination reactions. It also is used in fire-retardant resins for soldering of flux for deposition of molybdenum coating and to prepare several other molybdenum compounds, including molybdenum oxychlorides and hexacarbonyl. 

We found in 1974 that phenylacetylene polymerizes with tungsten hexachloride (WC16) and molybdenum pentachloride (MoC15) 6). Since then, we have exploited new effective catalysts, and polymerized various substituted acetylenes. An account of the polymerization by Mo and W catalysts has been reported7). 

SYNTHESIS Ring-opening polymerization of cyclopentene. Trflns-jxrlypentenamer is produced by Ziegler-Natta polymerization employing a catalyst based on aluminum triethyl/tungsten hexachloride compound. Aluminum diethylchloride/ molybdenum pentachloride compounds may be employed to produce the as isomer. Both macrocycles and linear chains are produced during polymerization. 

The use of molybdenum compounds in organic synthesis has attracted greater attention. Thus, molybdenum hexacarbonyl has been used in various reactions, such as the preparation of disulfides from sulfonyl chlorides, the alkylation of aryl derivatives, and the synthesis of 4-quinazolones from amines Oxygen has been replaced by fluorine with molybdenum hexafluoride. Molybdenum pentachloride in combination with hydroperoxides has served as oxidant Chelates of MoOg " have been investigated as catalysts for oxidations with molecular oxygen 2,2-Dichloro-7-butyrolactones have been prepared from olefins and methyl trichloracetate with cyclopentadienylmolyb-denum tricarbonyl dimer as catalyst ... 

Since the middle seventies soluble polyacetylenes with not too small molecular weight were obtained. Using for the first time tungsten hexachloride (WClg) and molybdenum pentachloride (Mods) catalysts, Masuda et al (5) were able to polymerize phenylacetylene, hereafter noted PPA, with a molecular weight larger than 1()4. 

Apart from the oxides and sulphides, other groups of simple compounds are the halides, chalcogenides and molybdates, and there are a number of well characterised organic compounds. Simple halides can be prepared by direct reaction between molybdenum powder and chlorine, fluorine or bromine, and the pentachloride MoClg has been used as a chlorination catalyst. 

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