V. C. Papadimitriou

IR laser-induced decomposition of hexamethyldisiloxane for chemical vapour deposition of nano-structured hydrido(methyl)silicone powders

Abstract The infrared laser-induced decomposition of hexamethyldisiloxane with high-fluence laser pulses affords gaseous C1–C2 hydrocarbons, dimethylsilane and trimethylsilane, all of which confirm a multitude of decomposition steps involving cleavage of the strong SiO bond. The process carried out in the absence or presence of hydrogen affords chemical vapour deposition of solid nano-structured hydrido(methyl)silicone powders and represents the first thermal access to these materials from peralkylated siloxane precursor.

Kinetic study for the reactions of chlorine atoms with hexamethyldisiloxane, 1,1,3,3-tetramethyldisiloxane, and 1,3-dimethyldisiloxane

Abstract The absolute rate constants for the reactions of chlorine atoms with (CH 3 ) 3 SiOSi(CH 3 ) 3 , (CH 3 ) 2 HSiOSiH(CH 3 ) 2 , and (CH 3 )H 2 SiOSiH 2 (CH 3 ) were measured in the gas phase over the temperature range 273–363 K, using the very low pressure reactor (VLPR) in a molecular flow system. The absolute rate constants were temperature independent and take the values (in cm 3 molecule −1 s −1 , 2 σ uncertainties): k 1 =(1.00±0.19)×10 −10 , k 2 =(1.98±0.29)×10 −10 , and k 3 =(2.42±0.25)×10 −10 . All title reactions proceed via the abstraction of C–H and/or Si–H hydrogen leading to the formation of HCl. The results show that the reactivity of Si–H bond towards Cl atom attack is higher than the reactivity of the C–H bond.