Silicon-cobalt bonds, cleavage

Hydrolysis or condensation with allyl bromide showed retention of configuration to occur at silicon. However, products of low optical purity were obtained. It is difficult to know whether some racemisation had occurred in the silicon-cobalt bond cleavage or whether it is due to a low configurational stability of the silyl Grignard reagent. 

Dimethyl(trimethylsilyl)phosphine (63) reacts with aluminium chlorides with cleavage of the silicon-phosphorus bond,58 as shown for aluminium trichloride. The same phosphine (63) reacts with the cobalt derivative (64) as shown.59... 

A related effect is that silicon-transition-metal compounds, once formed, undergo Si-M bond cleavage when dissolved in polar solvents (252,262,300,305,306,310). The products are often complex, but have been shown to include a cluster compound in one case involving cobalt (252). 

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