Reactions of 1,2-dichlorotetramethyldisilane with transition metal carbonyl anions, NaCo(CO) 4 and Na 2 Fe(CO) 4 , proceed easily to give monodisplacement products. Thus, reaction with NaCo(CO) 4 yields a neutral chlorodisilanyl cobalt complex, Cl(CH 3 ) 2 Si(CH 3 ) 2 SiCo(CO) 4 , and the analogous reaction chlorodisilanyltetracarbonylferrate salt, [Cl(CH 3 ) 2 Si(CH 3 ) 2 SiFe(CO) 4 ] − Na + . The β-chloride of Cl(CH 3 ) 2 SiCo(CO) 4 was unreactive toward BCl 3 . Prolonged reaction with CaCo(CO) 4 resulted in formation of the cluster compound, (CO) 9 Co 3 COSi(CH 3 ) 2 Si(CH 3 ) 2 Co(CO) 4 and of bis(μ-dimethylsilylene)bis(tricarbonylcobalt)(CoCo).