INTRODUCTION
There are many enzymatic reactions of interest, in which molecular oxygen
participates and some metal ions play an important role as activator of oxygen molecules."
It has been suggested by KobayashiZ7 that the molecular oxygen may be
excited to singlet state by coordinating to metal ion in enzyme, such as ferrous ion
in pyrocatechase or hemoglobin and copper ion in ascorbate oxidase.
The oxygenated metal complexes may be very attractive as models of such enzymatic
systems in the study of oxidation mechanisms of the oxygen molecule. Otsuka
et a1.3' reported that the oxidation of t-butyl isocyanides (Bu 'NC) was catalyzed by
the oxygenated nickel complex (Ni (Bu 'NC) 202). Oxidations, by molecular oxygen,
of triphenyl phosphine (Ph3P) and hexyl isocyanide (C6H11CN) were accelerated
in the presence of triphenyl phosphine chelates (M (Ph3P)4: M=Pd, Pt), and the
existence of oxygenated complexes of palladium and platinum was confirmed as
an intermediate in the oxidation process.4'