Comparison of Implantation Reactions with Hot Atom Reactions in Geometrical and Optical Isomers of Metal β-Diketonates

A systematic comparison of implantation reactions with hot atom reactions was performed using geometrical (mer- and fac-) and optical (A and A) isomers of tris(β-diketonato)metal(III). A regularity was found in irradiated geometrical isomers. The complex yield involved the parent and its isomer form; the parent form could be divided into two parts, one of which (P₁) was structure-dependent and the other (P₀) nearly independent for both implantation and hot atom reactions. The ratio of isomer to parent I/P was found to be dependent on the nuclear reactions in optical isomers; it was small (< 0.15) in low recoil energy (n,y) reaction and attained saturation (nearly one half) in higher recoil energy reactions. On the basis of the experimental data probable mechanisms of isomerization and retention were discussed. They involved (1) a directed bond rupture mechanism, (2) a caged twist mechanism and (3) simple recombination for low-energy hot atom reaction and the corresponding mechanisms for high-energy hot atom reaction and implantation reaction.