Observation of photochemical C-N bond cleavage in CH3N3: a new photochemical route to cyclic N3.

We report VUV-photoionization based photofragmentation-translational spectroscopy data, providing a comprehensive study of the collision free photochemistry of methyl azide (CH3N3) at 193 nm. We report the first observation of the production of methyl and the N3 radical and derive the translational energy release distribution of this reaction. The most probable translation energy is only 8%, and the maximum translational energy is only 60% of the available energy, taking CH3 + linear N3 as the zero of energy.

The simplest all-nitrogen ring: photolytically filling the cyclic-N3 well.

We report evidence that cyclic-N(3) is exclusively produced in the 157-nm photolysis of ClN(3). Photoproduct translational energy measurements reveal a single-peaked distribution for an N(3)-formation channel with maximum and minimum translational energies matching the theoretically predicted minimum and maximum binding energies of cyclic-N(3), respectively. The absence of linear-N(3) greatly simplifies the data analysis.

Collision-free photochemistry of methylazide: observation of unimolecular decomposition of singlet methylnitrene.

Methylazide photolysis at 248 nm has been investigated by ionizing photofragments with synchrotron radiation in a photofragmentation translational spectroscopy study. CH3N and N2 were the only observed primary products. The translational energy release suggests a simple bond rupture mechanism forming singlet methylnitrene, 1CH3N, and N2.

The heat of formation of chlorine-isocyanate and the relative stability of isoelectronic molecules: an experimental and theoretical study.

Accurate thermochemical data of small molecules are invaluable to the progress of every aspect of chemistry, especially in the atmosphere, combustion and industry. In this work, photofragmentation translational spectroscopy and 1st principles electronic structure theory reveal the literature value of the heat of formation of chlorine-isocyanate to be in error by more than 40 kcalmol. We report a revised experimental value for D0(Cl-NCO) = 51+/-3 kcal/mol which leads to a Delta Hf (ClNCO) = 8.

Two photoionization thresholds of N3 produced by ClN3 photodissociation at 248 nm: further evidence for cyclic N3.

We present results of near-threshold photoionization of N3 photofragments produced by laser photodissociation of ClN3 at 248 nm. The time of flight of recoiling N3 is used to resolve two photochemical channels producing N3, which exhibit different translational energy release. The two forms of N3 resolved in this way exhibit different photoionization thresholds, consistent with their assignment to linear (X 2pi(g)) and cyclic N3.