Laser-induced decomposition of 1,1-dichloro-1-silacyclobutane for gas-phase deposition of reactive solid polycarbosilane

Article abstract of DOI:10.1016/0022-328X(94)88025-5

Continuous-wave CO2 laser photosensitized (SF6) decomposition of 1,1-dichloro-1-silacyclobutane (DCSCB) leads to volatile ethene, methyltrichlorosilane, 1,1.3,3-tetrachloro-1,3-disilacyclobutane (TCDSCB) and a solid material.The reaction is assumed to be initiated by competitive (2+2) cycloreversion and dehydrochlorination.The amounts of depleted DCSCB and those of the ethene and CH3SiCl3 that are formed, as well as detection of methyltrichlorosilane-d₁ and methyltrichlorosilane-d₂ in the decomposition of DCSCB carried out in an excess of DCI provide indirect evidence for the intermediacy of dichlorosilene Cl2Si=CH2 and chlorosilyne CISi<*>CH.The solid deposit is judged to be mostly poly(dichlorocarbosilane): it reacts with gaseous methanol, trifluoroethanol, trifluoroacetic acid and water. Key words: Silane; Laser-induced deposition; Polycarbosilane; Chlorosilyne