The First Sideways-Bonded Peroxo Complex for a Tetraaminecobalt(III) Species

Cobalt(II) salts react with H2O2 in the presence of 2 equiv of
tetramethylethylenediamine (tmen) to produce a stable sideways
bonded mononuclear peroxo complex [Co(tmen)2O2]ClO4 which
has been characterized chemically and by a single crystal X-ray
determination. This is the first such tetraaminecobalt(III) complex,
indeed, the first for any tetraaminemetal ion complex. The
mononuclear peroxo complex can also be synthesized by O22-
anation of cis-[Co(tmen)2(OH2)2]3+. This reaction is reversed in acid,
and this offers the potential to develop Co(III) catalyzed oxidation
reactions.