A. Thon et al., A MASS SPECTROSCOPIC STUDY OF THE VAPOR-PHASE THERMAL-DECOMPOSITION OF TRIMETHYLAMINE, Journal of the Electrochemical Society, 144(3), 1997, pp. 1127-1130
Trimethylamine has been used in the growth of compound semiconductors
either through the formation of an adduct, as in trimethylamine allane
, or as a possible growth reactant. The kinetics of the gas-phase deco
mposition and dominant reaction products relevant to these application
s were determined in this study. The multistep thermal decomposition o
f trimethylamine in hydrogen (H-2 and D-2) in a laminar-flow tube reac
tor was studied by in situ mass spectroscopy and the analysis of isola
ted decomposition products. A dimethylamino radical and a methyl group
are formed in a first-order Arrhenius-type decomposition that begins
at similar to 525 and is complete at similar to 650 degrees C. Additio
nal products of this first step were deuterated methane, CH3D, (in D-2
) and ethane, C2H5. The activation energy is 50.8 kcal/mol. In subsequ
ent steps the dimethylamino radical degrades through the series N-meth
ylenemethylamine, (CH3)N = CH2, the imidoyl radical (CH3)N = (CH)-H-.,
and hydrogen cyanide, accompanied by loss of H-2, hydrogen radical, a
nd methyl radical, respectively, as well as by the formation of uniden
tified solids.