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Tritium atoms with 2.8-eV kinetic energy have been formed by 1849-Å photolysis of TBr, and have been reacted with CH4 in the presence of Br2. In addition to HT from the abstraction reaction known in thermal systems, the direct substitution of T for H to form CH3T has been observed. The ratio of HT/CH3T is 3.6 to 4.0 in low Br2 mole fraction. In Br2 mole fractions exceeding 0.5, this ratio is reduced to 3.0, and the absolute yields of both HT and CH3T are greatly reduced. The formation of HT and CH3T from hot reactions of T with CH4 competes with the hot reaction of T with BR2 to form TBr.

The laboratory photolysis of chlorine nitrate (ClONO2) with 302.5 nm ultraviolet light leads to the destruction per quantum of 4 molecules of ClONO2 and the formation of 1 molecule of O2, 2 of Cl2 and 2 of N2O5. These quantum yields are not consistent with the current assumption that the primary photolysis step for ClONO2 in the stratosphere leads to the formation of ClO plus NO2. A consistent mechanism exists in which the photolytic step involves the decomposition of ClONO2 to ClONO + O(³P). The onset of observed absorption of radiation by ClONO2 corresponds approximately to the thermodynamic accessibility of this simple splitting away of an O atom. The photolysis of ClONO occurs very rapidly in the stratosphere, either to Cl + NO2 or ClO + NO. The substitution of either Cl + NO2 + O or ClO + NO + O for ClO + NO2 as the eventual photolysis products from ClONO2 is not expected to cause appreciable alteration in predictions from stratospheric modeling.