C-H bond activations by the HO˙/(Salophen t -Bu )Co(II) radical pair generated via homolysis of a terminal Co(III)-OH bond.

The reactive HO˙/(Salophen t -Bu )Co(II) radical pair was observed to be generated via homolysis of the terminal Co(III)-OH bond in transient (Salophen t -Bu )(L)Co(III)(OH) (L = Py, MeOH) complexes as indicated by UV-Vis and EPR measurements. Based on this elementary process, C-H bond activations in acetone, 2-butanone, acetonitrile and benzene were achieved under ambient conditions. For the reactions of the first three substrates, the alkylcobalt(III) complexes were formed as the products.