A platinum catalyzed hydrosilation reaction between 3,4,-dichlorobutene and the hydrogen-terminated (100) Si surface was used to bond dichlorobutane molecules to silicon wafers treated with dilute HF acid. In situ infrared, x-ray photoelectron spectroscopy, and time-of flight secondary ion mass spectroscopy were used to characterize the modified silicon surfaces. The results from this investigation indicate that 3,4,-dichlorobutene reacts with surface silicon hydride groups to yield 3,4,-dichlorobutane, which bonds to the surface via Si-C bonds. This work demonstrates that organic molecules can be selectively patterned onto hydrogen-terminated silicon wafers using standard microelectronic patterning methods.