Thermal unimolecular decomposition of 1,3,5‐trioxane: Comparison of theory and experiment

Abstract

The unimolecular decomposition of 1,3,5-trioxane into three formaldehyde molecules has been studied thermally at eight temperatures between 523 and 603 K using mixtures highly diluted with Ar. Under these conditions, the only decomposition product detected by means of FTIR analysis was formaldehyde. At 588 K, the effect of total pressure was examined between 25 and 800 torr; a noticeable decline in the first-order rate constant was observed only at pressures below 500 torr. A least-squares analysis of the measured high-pressure, first-order rate constants leads to exp [(-25,620 computed with the transition-state theory using the molecular and TST parameters predicted by the BAC-MP4 method.

High-Temperature Experimental and Theoretical Study of the Unimolecular Dissociation of 1,3,5-Trioxane

“…This mechanism for 1,3,5-trioxane decomposition was confirmed in a laser schelieren study by Irdam and Kiefer 14 and later by Aldridge et al 12 and Hochgreb and Dryer…”

“…[1][2][3] Its importance in combustion led to a number of high temperature kinetic studies for its pyrolytic dissociation [3][4][5][6] and bimolecular reactions. 1,[7][8][9][10] A substantial number of earlier studies 5,7,9,[11][12][13][14][15][16] consisted of utilizing 1,3,5-trioxane (C 3 H 6 O 3 ) as a clean thermolytic source of formaldehyde to avoid the problem of formaldehyde polymerization. These studies assumed reaction (1)…”

“…to be an instantaneous process at high temperatures (above 1300 K τ < 0.5 µs) 5 to yield three formaldehyde molecules via a simple unimolecular and probably a concerted mechanism 12,17 .…”

An Experimental and Computational Study of the Thermal Oxidation of C6H5NO by NO2

“…The detailed experimental procedure of the pyrolysis/FTIR spectrometric technique can be found in our earlier studies. 3,4 For kinetic measurements, the reactor was filled to an appropriate pressure with a mixture of NO 2 and Ar, to which an Ar-diluted mixture of C 6 H 5 NO was added up to 760 ((0.5) Torr in the temperature range 393-473 K. Pyrolyzed or unpyrolyzed reference samples were expanded into the absorp-* To whom correspondence should be addressed. E-mail: chemmcl@ emory.edu.…”

Simple, non-catalytic permethylation of catechol derivatives in subcritical and supercritical water

“…affording 10 equiv. of formaldehyde to 1 under the reaction conditions) [27,28] in sub-CW and SCW in a batch type reactor (10 mL volume) (Scheme 1). Although the reaction was performed under inert conditions using N 2 -bubbled water under N 2 atmosphere, treatment of 1 with an excess amount of 2 in sub-CW and SCW produced black reaction mixtures.…”