Accession Number : AD0615558

Title :   THE THERMAL STABILITY OF SOME ARYLSILANES.

Descriptive Note : Interim rept. for 1 May 60-30 Apr 64,

Corporate Author : BATTELLE MEMORIAL INST COLUMBUS OHIO

Personal Author(s) : Levy,Arthur ; coutant,Robert W. ; Merryman,Earl L. ; Trent,Donald E.

Report Date : APR 1965

Pagination or Media Count : 45

Abstract : The decomposition of the following arylsilanes was investigated by static and flow procedures: (I) tetraphenylsilane, (II) triphenylsilane, (III) diphenylsilane, (IV) monophenylsilane, (V) hexaphenyldisilane, (VI) triphenyl-bromophenylsilane, (VIII) diphenyl-bis (bromophenyl)silane. I and V decompose via first-order processes, and yield as major products benzene, triphenylsilane, and o-biphenylyl triphenylsilane (and tetraphenylsilane in the case of V). II, III, and IV decompose via second-order processes, disproportionating to corresponding higher and lower phenyl silanes, e.g., II yields I + III, III yields II + IV, and IV yields III + SiH4. VI and VIII decompose about 100C below I and yield tetraphenylsilane and what appears to be triphenylbromosilane. The following rate data were obtained for the more thoroughly studied silane pyrolyses: (I) 1n k (/min) = 34.40 - 67,000/RT, T = 561-588C; (II) 1n k (1/mole-min) = 49.76 - 70, 100/RT, T = 459-505C; (III) 1n k (1/mole-min) = 44.99 - 55,800/RT, T = 383-419C; (V) 1n k (/min) = 25.60 - 44, 700/RT, T = 465-511C. The high-frequency factors obtained for II and III, and the low-frequency factors obtained for I and V do not permit one to generalize on a single decomposition mechanism, applicable to all the arylsilanes at this time. (Author)

Descriptors :   (*SILANES, PYROLYSIS), POLYCYCLIC COMPOUNDS, STABILITY, DECOMPOSITION, REACTION KINETICS, DISPROPORTIONATION, FREE RADICALS, THERMOCHEMISTRY

Distribution Statement : APPROVED FOR PUBLIC RELEASE