Selective Laser Photocatalysis of Bromine Reactions

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Science  07 Jul 1967:
Vol. 157, Issue 3784, pp. 40-43
DOI: 10.1126/science.157.3784.40


The results have shown that selective excitation obtained with a tunable monochromatic laser is a useful technique for studying photochemical and energy transfer processes. A new phenomenon in the photochemistry of bromine was observed, in which bound excited molecules, and not atoms, were formed in the primary process. The mechanism of the subsequent reaction consists of collisional dissociation of the excited molecules into atoms, which then initiated free-radical chains. A quantitative estimate of the collisional electronic relaxation rate for excited bromine molecules was obtained, and a new upper limit to the continuous absorption strength at 14,400 cm-1 was determined.