Copper(II) complexes of the ligands (6-methyl-2,2'-dipyridyl)methane (
MeDPM) and (6,6'-dimethyl-2,2'-dipyridyl)methane (diMeDPM) were prepar
ed and used as catalysts for the oxidation of 3,5-ditertbutylcatechol
to 3,5-ditert-butyl-o-benzoquinone. The rate of reaction was determine
d in the presence and absence of base (KOH) in methanol. The kinetic d
ata are interpretated, postulating two reactive species towards molecu
lar oxygen: a copper(I) complex and a species described as a ternary c
opper(II) catecholate complex. (C) 1997 Elsevier Science Ltd.