Site??specific fragmentation following Si: 2pphotoexcitation of (trifluorosilyl)(trimethylsilyl) methane [F3SiCH2Si (CH3) 3 (FSMSM)] has been studied by means of photoelectron?? photoion and photoion–photoion coincidence techniques. The total photoionization efficiency curve of FSMSM has only one broad peak near the Si: 2p core??ionization threshold and no evidence is obtained for the occurrence of selective excitation of each of ...