Photochemistry of ultrahigh laboratory magnetic fields. Photolysis of micellar solutions of dibenzyl ketones and phenyl benzyl ketones at 145 000 G. Observation of a .DELTA.g.vector.H effect on the cage reaction

Abstract

Experiments are described that were carried out to determine whether the reactions of solvated triplet radical pairs in micelle cages are determined by Zeeman-induced mixing at ultrahigh magnetic fields. Dibenzyl ketone and phenyibenzyl ketones were studied as prototypes, and data are tabulated for magnetic field effects in the cage reactions of para-monosubstituted dibenzyl ketones. The noted result that the percent cage is the same at low field and at ultrahigh fields is interpreted to mean that a new mechanism, spin-orbit coupling, dominates the reversible singlet ..-->.. triplet intersystem crossing in molecules. Data are also tabulated to show the influence of applied field strength on the percent cage produced in the photolysis of 1,2-diphenyl-2-methylpropanone and some of its isotopically substituted derivatives. From the data presented, it is concluded that the extent of cage recombination of benzyl radicals and/or substituted benzyl radical pairs produced in micelle aggregates depends on the strength of the external laboratory field applied to the samples. 21 references, 1 figure, 2 tables. (BLM)