A kinetic study of the very low-pressure pyrolysis of ethylbenzene (I), 2-phenylethylamine (II), and N,N-dimethyl 2-phenylethylamine (111) (1) (2) (3) above 900 K yields the heats of formation of aminomethyl ( A ) and N,N-dimethylaminomethyl ( B ) radicals: AHf,300K(A) = 30.3 and AHf300K(B) = 27
Decomposition of methylamino and aminomethyl radicals. The heats of formation of methyleneimine (CH2NH) and hydrazyl (N2H3) radical
β Scribed by M. A. Grela; A. J. Colussi
- Publisher
- John Wiley and Sons
- Year
- 1988
- Tongue
- English
- Weight
- 314 KB
- Volume
- 20
- Category
- Article
- ISSN
- 0538-8066
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β¦ Synopsis
A kinetic analysis of the thermal decomposition of methylamino and aminomethyl radicals into methyleneimine, reactions (1) and ( ):
(1)
.0 ? 3 kcal/mol in excellent agreement with ion cyclotron resonance spectroscopy measurements and to a pi bond energy of E, = 55.0 kcal/mol in CH,=NH which is comparable but smaller than to the corresponding value in CH,=CH, (63.7 kcal/mol). Assuming that E,(CH,=NH) = 0.5 [E,ICH,=CH,) + E,(NH=NH)] then requires that E,(NH=NH) = 46.8 kcal/mol in diimine and BDE(N2H3-H) = 87.5 kcal/mol i.e. about 11.5 kcal/mol larger than current data for hydrazine but otherwise consistent with additional evidence.
The entropy and heat capacity of methyleneimine, calculated from recent infrared and microwave spectroscopic data using the rigid rotor harmonic oscillator approximation, are also reported.
π SIMILAR VOLUMES
The rate of the reaction CH212 + H I 2 CH,I + I , has been followed spectrophotometrically from 201 .O to 31 1 .Z0. The rate constant for the reaction I + CH,I, CH,I + I, fits the equation, log (k,/M-'sec-') = 11.45 f 0.18 -(15.11 f 0.44)/0. This value, combined with the assumption that E2 = 0 & 1 k