Photolysis of solid dimethylnitramine. Nitrogen-15 study and evidence for nitrosamide rearrangement

Abstract

difficulties in making H atom concentration measurements. The hydrogen atoms are probably trapped in multiple sites with different relaxation times at the different sites.11 Since some of these sites are saturated, intensity measurements using our present apparatus are unreliable. When the microwave power is reduced to a low level, the HCO signal is reduced below the threshold detection level without completely alleviating the H atom saturation.Although other mechanisms cannot be ruled out, it is postulated that reaction mechanisms 3 and 4, the H K. Suryanarayanan and Suryanarayana Bulusu atom abstraction from formaldehyde and the recombination of H atoms and CO molecules, are the most probable mechanisms for the increase of formyl radicals at 87°K.

Hydrogen pentazole: does it exist?

“…The stability of these molecules, and whether they can be successfully synthesized, depends on the activation energy for decomposition, among other factors. 14 To investigate possible unimolecular decomposition pathways we use "eigenvector following"15 to locate two possible transition states (TS). Starting from the ground-state geometry, we determine a symmetric and a nonsymmetric pathway (Figure 2).…”

“…; The Chemical Society: London, 1958. (14) Questions of stability should also consider the potential for low-lying triplet electronic states that could provide a spin-forbidden decomposition path and fast bimolecular reactions of transients.…”

Ab initio study of the photodissociation of nitrosoalkanes and nitrosamines

“…In the gas phase at low pressures, the molecule eventually dissociates, by whatever mechanism (no fluorescence has been reported for excited nitrosamines, and the fluorescence quantum yields of the analogous nitrosalkanes are very low).10,13 In solution, on the contrary, the extra vibrational energy can be dispersed in the medium, after a radiationless transition to the ground state or even to Tj; therefore, the dissociation quantum yields may differ significantly from 1, but only if some kind of electronic deexcitation competes efficiently with vibrational predissociation. In the condensed as well as in the gas phase, the very efficient recombination of amino and NO radicals makes it difficult to measure or even to detect the photodissociation rate.39, [44][45][46][47][48] A deformation of the potential surface of S1; caused by substitutents or solvent effect, can easily produce a shallow minimum at rather large i?NN distances, and indeed this seems to be the case for iV-nitrosodiphenylamine. 49 If such a biradical exists, our calculations indicate that it should be twisted and pyramidalized as in III.…”

Flash photolysis of s‐trinitrobenzene solutions

“…The fogging of the quartz discs was prevented by blowing dry nitrogen on them at room temperature. Steady-state photolysis was carried out using a helical low-pressure mercury lamp with main output at 254 nm [12].…”