CATALYTIC AUTOXIDATION OF 1-DECANETHIOL BY COBALT(II) PHTHALOCYANINETETRASULFONATE INTERCALATED IN A LAYERED DOUBLE HYDROXIDE

A hydrotalcite-like layered double hydroxide (LDH) interlayered by cobalt(II) phthalocyaninetetrasulfonate, [Mg5Al2(OH)14][CoPcTs]0.5.6H2O, has been prepared in 92% yield by reaction of Mg0.63Al0.25 square 0.12O (square = vacancy) with the [CoPcTs]4- ion in aqueous solution. The intercalated complex was twice as active for the catalytic autoxidation of aqueous 1-decanethiol at 35-degrees-C and pH 9.25 than the homogeneous complex under equivalent reaction conditions. More importantly, the homogeneous catalyst was completely deactivated after one catalytic cycle involving only approximately 150 turnovers, whereas no loss in activity was observed for the intercalated catalyst after five consecutive reaction cycles for a total of more than 770 turnovers. Thus, layered double hydroxide intercalation compounds appear to be exceptionally promising support materials for improving the longevity of certain types of biomimetic metallo macrocyclic catalyst.