UV photolysis of n-C3F7I. Radiative lifetime of metastable iodine atoms

The photolysis of n-C₃F₇I and C₂F₅I has been studied with a frequency doubled dye laser at fixed frequency in the UV by detection of time resolved resonance fluorescence of the metastable iodine formed. The rate coefficient for quenching of I(²P_{$\text{1}\text{2}$}) by n-C₃F₇I has been obtained as k = (4.6 ± 0.3) × 10^?17 cm³ molecule_?1s_?1. This value is by more than an order of magnitude lower than published values. Further proof is given for the value of the radiative lifetime of the metastable atoms which was obtained recently by this experimental method. This answers questions raised by Husain et al. on this subject in this journal.