Photolytic reactions reaction vessel

Photolytic reactions of the thiocarbene complexes are conducted in a reation vessel surrounded by a filter solution for X > 400 nm. This solution is prepared by the addition of 54 mL of 30% aqueous ammonia to a solution of 4.5 g of copper sulfate in 6 mL of water. The solution is added to a second solution containing 22.5 g of sodium nitrite and 30 mL of water. Finally, the mixture is diluted with water to 1000 mL. 

The PNA/pyridine actinometer is useful for very fast reactions. In sunlight, it can be adjusted to half-lives between a few minutes and about 12 h. The upper time limit is determined by the (very high) k value of PNA [ 5000 einstein (mol PNA)-1 d-1 for a midsummer day at 40°N latitude], and the (rather small) d> R value of 3 x 10-4 (Dulin and Mill, 1982 Leifer, 1988). In comparison, as we discussed earlier, for the same geographic latitude and time, PNAP exhibits a k value that is about 10 times smaller [i.e., 532 einstein (mol PNAP)-1 day"1], and it has an even smaller quantum yield as compared to PNA (0°R < 10 5, Dulin and Mill, 1982). Hence, although PNAP absorbs sunlight at an appreciable rate, its (direct) photolytic half-life would be very large in a natural water. In the presence of pyridine in a test vessel, however, the photolytic half-life can be adjusted to range between a few hours and several months (for details see Dulin and Mill, 1982, or Leifer, 1988). 

Aq solns of 1,3,5 carbon-14 labeled TNT were irradiated in closed vessels for periods of 24, 72,144 and 312 hrs. The radioactivity of the irradiated TNT, as determined by liq scintillation counting, decreased with increased time of exposure. Labeled C02 was found to be one of the photolytic products indicating that ring cleavage occurred. Unidentified volatile products of the reaction were trapped by activated charcoal. Most of the photochemically converted compds remaining in soln were found to be pohtr and unextractable with benzene or acetone... 

---