II. Primary processes in the photolysis of gaseous 1-nitropropane

A study of the primary processes in the photolysis of gaseous I-nitropropane at 22°C and 100 ± 1°C is undertaken. 1-Nitropropane undergoes a photochemical reaction giving rise to a six-member complex which produces ethylene, the major photolysis product. This is a typical intramolecular non-radical Norrish Type I1 process and is the most important primary process (1): At higher temperatures homolytic split of C-N bond takes place according to reaction (2), another important primary process: CH,CH,CH,NO, + hv + CH,CH,CHj + NOj. The formation of propylene which is also a major product of photolysis may be the result of the third primary process: CH, CH, CH, NO, + hv + CH3CH=CH, + HONO. The major photolysis products resulting from these processes as identified by GLC and GLC-MS included ethylene, propy-lene and methyl nitrite. The minor products of photolysis were methane, methyl nitrate, ethyl nitrite, ethylene oxide, propyl nitrite, formaldehyde, propionaldehyde, water, nitric oxide and nitrogen dioxide. The rate of formation of ethylene, and to a lesser extent that of propylene increased with increase in temperature and decreased with the introduction of nitrogen. A mechanism of photolysis as a consequence of the primary processes is suggested and discussed.