Functionalization of atomically flat, hydrogen terminated, 1 x 1 and 2 x 1 (100) silicon surfaces via reaction with 1-alkyne: a DFT study

A structural and thermodynamical study of the derivatization of atomically flat, hydrogen terminated, 1 x 1 and 2 x 1 (1 0 0) Si surfaces with 1-octyne is reported. The major conclusion of the DFT analysis based on cluster models of the Si surface is that the alkyne is grafted to silicon, leaving in the hydrocarbon moieties a large fraction of unreacted pi bonds. In particular, for the monohydrogenated 2 x 1 (1 0 0) Si surfaces, the grafting of 1-octyne stops after the hydrosilation to alkenyl products, leaving the silicon surfaces equipped with a second reactive group (the C=C group) in addition to the one carried by R.