The photolysis of formaldehyde vapor has been examined at 1470 and 1236 Å. Mixed isotope (H2CO+D2CO) and radical scavenger (C2D4) experiments have been utilized in addition to inert gas pressurization and lamp intensity attenuation. The quantum yields for H2 and CO formation are both equal to 2; and both are independent of pressure and lamp intensity at 1470 and 1236 Å. The primary quantum yield for molecular hydrogen elimination (ΦII) was determined from the scavenger results and also from the mixed isotope work. The two values obtained are in reasonably good agreement, viz., ΦII = 0.5. The mechanism most consistent with the experimental observations is as follows: H2CO+hυ→H2+CO, H2CO+hυ→2H+CO, H+H2CO→H2+HCO, 2HCO→H2+2CO, where the quantum yields of primary process (II) and (III) are both equal to 0.5.
Relative rate constants for reaction of monomethylamine and trimethylamine with boron trifluoride are reported for the pressure range 0.04-600 Torr. The limiting ratio at low pressure is about 0.06, and the extrapolated high-pressure ratio is of the order 4. The half-pressure for quasi-bimolecular behavior of the monomethylamine-boron trifluoride system is in the vicinity of 70 Torr. When the data are combined with those of Kistiakowsky, et a!., individual pressure-dependent rate constants can be estimated. The amine-BFs series has loose activated complexes and low energy for redistribution among internal modes, making it an unusual candidate for theoretical unimolecular study.
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