Alkyl manganese pentacarbonyl compounds (CO)5MnR (R = CH3, p-CH2C6H4CH3, p-CH2C6H4OCH3) were synthesized by metalation of manganese pentacarbony potassium salt with corresponding alkyl halides in ether. Photolysis of these with 1-2 equivalent of (CH3)2(C6H5)SiH or (CH3)(C6H5)2SiH in C6D6 solution at 5℃ produces silyl manganese pentacarbonyl compounds (CO)5MnSi(C6H5)(CH3)2 and (CO)5MnSi(C6H5)2(CH3) respectively (yield 70-88%). Quantative generation of corresponding methane, p-xylene, p-methyl anisole was also observed along with minor byproducts Mn2(CO)10 (<4%), (CO)4MnH(SiMe2Ph) (<9%).