Designer ligands. Part 9. Catalytic activity of biomimetic cobalt(II) and copper(II) complexes of multidentate ligands

A series of Co(II) and Cu(II) complexes have been prepared, and their structures investigated using a combination of microanalytical, spectroscopic, electrochemical and X-ray crystallographic techniques. The capacity of the complexes to oxidise phenol and catechol substrates has been examined, and while some of the Cu(II) complexes catalyse oxidative coupling of 2,4-di-t-butylphenol (DTBP) to the corresponding biphenyl (9-13%), the Co(II) complexes catalyse efficient conversion (up to 92%) of 3,5-di-t-butylcatechol (DTBC) to the o-quinone within 24 h.