MAGNETIC-FIELD EFFECTS ON THE HYDROGEN ABSTRACTION REACTIONS OF TRIPLET BENZOPHENONE WITH THIOPHENOL IN NONVISCOUS HOMOGENEOUS SOLUTIONS

The hydrogen abstraction reaction of triplet benzophenone with thiophe nol at room temperature was investigated in several nonviscous homogen eous solutions (eta = 0.29-3.33 cP) by means of a nanosecond laser fla sh photolysis technique under magnetic fields of 0-10 T. The escape yi eld of the benzophenone ketyl radical decreased with increasing magnet ic field strength from 0 to 10 T. In 2-methyl-1-propanol (eta = 3.33 c P), the yield at 10 T reduced to 80 +/- 2% of that at 0 T. The observe d magnetic field effects can be interpreted by the Delta g mechanism w hen the geminate recombination process is faster than or comparable to the escape one.