Ozonation kinetics of indeno (1,2,3-c,d) pyrene as a model substance of six-cyclic aromatic hydrocarbons

The regularities of ozonation of indeno (1,2,3-c,d) pyrene as a model subst ance of 6 - cyclic aromatic hydrocarbons have been investigated. On the bas is of the experimental results it may be said that within the temperature r ange investigated (16-33 degrees C) indeno(1,2,3-c,d) pyrene is oxidized in the presence of ozone. The use of methanol as an intermediate compound dur ing the dissolution of indeno(1,2,3-cd) pyrene in an aqueous solution affec ts the total process rate. The turbidity of the suspension has been determi ned by spectrophotometric measurement of the optical density. The mean volu me of the aggregates is equal to a sphere with a diameter of 120 nm. The ac tivation energy of the reaction of ozonation is of the order of 10 - 25 kJ/ mol and increases with the pH value. The rate is of a fractional order of m agnitude with respect to the reagents. With increasing medium pH the reacti on rate decreases. This is explained assuming that the oxidation of indeno (1,2,3-c,d) pyrene proceeds mainly by direct interaction with ozone. The in itial data from the identification of the ozonation products demonstrate th e formation of primary and/or secondary ozonides with a molecular weight of 324.