Hg(63P1) photosensitization of 3-methylbut-1-ene. Part 1.—Reactions of vibrationally excited triplet 3-methylbut-1-ene and the 2-methylbuta-1,3-diyl biradical

Abstract

3-Methylbut-1-ene has been photosensitized by Hg(63P1) atoms in the gas phase at 24±1 °C, producing both vibrationally excited 3-methylbuta-1,2-diyl and 2-methylbuta-1,3-diyl biradicals in the triplet state. The pressure dependences of the quantum yields of the various reaction products have been investigated and a computer modelling treatment applied to the proposed reaction mechanism, thereby allowing rate constants for the major decomposition and isomerization reactions of these two intermediates to be derived. In addition RRKM calculations have been performed, enabling rough estimates of critical energies for three of these reactions to be obtained.