Dissociation of NH3 to electronic ground-state fragments by high-intensity CO2 laser radiation

Reactivity and kinetic properties of the NH2 radical in the gas phase

“…This is shown in Figure 4 and can be compared with similar plots obtained in the case of the isoelectronic OH and CH 3 radicals. The extrapolation yields 9.5 to i0 kcal mol -I for the activation energy of Reaction (21), which is close to the experimental evaluation. From the rate parameters of the reverse reaction and the equilibri%ml constant calculated from themodynsmic data, Gray et al [86] obtained E21 = 11.8 kcal mol -I .…”

“…Since the pioneering work of Letokhov [19,20], it is known that ammonia [19][20][21][22] and amines [23,24] can be dissociated into NH 2 + H (or ~q2 + alkyl radical) by a multiple photon absorption using an infrared CO 2 laser. More recently, Duncanson et al [25]used this method to dissociate hydrazine in order to study the kinetics of ~2 radical reactions.…”

Fluorescence and Double Resonance Studies of Energy Transfer

“…Indeed, in the experiment on NH3, dissociation fragments (NH,) were detected at a time following the C 0 2 laser pulse which was much shorter than the molecular gas-kinetic mean free time [20]. However, if one wishes to scale such a process to high throughputs of material, it will be necessary to work at relatively high pressures, at which collisional deactivation effects may become important.…”

Crossed Laser and Molecular Beams Studies of Multiphoton Dissociation

“…Experimentally, the usual approach to studying MPD has been to irradiate a low-pressure gas medium in a sample cell with C0 2 laser pulses and analyze the gas before and after the irradiation by infrared absorption and mass spectroscopy. In some cases 'induced ~uminescence in the gas has also been monitored during the irradiation, assuming the production of electronically excited fragments is not likely [11]. Measurements have been carried out on a wide variety of gases and gas mixtures as a function of pressure, laser frequency, power, pulsewidth, etc.…”