Rochow-Miiller process

Alternative technologies that are used to generate organosilanes on a commercial scale are the Rochow-Miiller direct process, which works best with low molecular weight alkyl and aryl halides [5] ... 

A direct synthesis of dihalodimethylsilanes 8a-d can be achieved by the reaction of silicon atoms with solid methyl halides 6a-d under concurrent irradiation with UV light (254 nm). Studies in argon matrices at 10 K uncovered all the details of these processes. The basic reactions are now well understood. The crucial step is the radical decay of the primarily formed n-adducts T-5a-d into a methyl radical and the corresponding Si-X radical. Hopefully, these studies can contribute to a better understanding of the decisive steps in the Rochow-Miiller synthesis. 

This contribution to the broad field of organosilicon chemistry including molecules and materials, marks a very unusual anniversary, the existence of which effectively contradicts a historical statement by the famous organosilicon pioneer F. S. Kipping, who believed 80 years ago that organosilicon chemistry would never gain industrial and commercial importance. Fifty years after the invention of the Miiller-Rochow process, the silicon industry achieved an annual worldwide turnover of US 4.700.000.000. This proves impressively that the basic process - independently developed by R. Muller and E. G. Rochow in 1941/2 - can be considered to be the most important innovation for organosilicon research work in industry and university. 

The proposed silylene mechanism gives an explanation for the high selectivity of (CH3)2SiCl2 formation in the "Direct Synthesis" of methylchlorosilanes (Miiller-Rochow process). Via an oxidative addition of CH3CI to methylsilylenes on the surface of a Cu/Si catalyst, (CH3)3SiCl2 is produced in a kinetically controlled process (Scheme 2). 

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