Dioxygen Binding by Cobalt(II) Complexes of 8,8'-bis(aminomethyl)-2,2'-biquinoline

Muhammad S. Khan, Nawal K. Al-Rasbi, Edwin C.Constable


A new series of Co(II) complexes of the type CoLX2 , where Lis a tetra-dentate ligand 8,8'-bis(aminomethyl)-2,2'-biquinoline  and X= SCN, BF4, I or NO3,  have been synthesized and characterized. The complexes have magnetic moments in the range typical of a low-spin d7 Co(II) center. The interaction of these Co(II) complexes with dioxygen was studied by E.S.R. spectroscopy. A dicobalt(III) peroxo-bridged complex was formed in DMF solution, associated with the formation of an E.S.R.-silent solution compatible with the formation of low-spin d6 Co(III) species. Similar behavior was also observed for the interaction of these Co(II) complexes with dioxygen in the presence of ancillary ligands such as pyridine and 2-methylimidazole. The dioxygen complexes proved successful as oxygen carrier oxidation catalysts for tripehnylphosphine and 2,6-bis(t-butyl)phenol.




Biquinoline; Cobalt(II); Dioxygen interaction; E.S.R.

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DOI: http://dx.doi.org/10.24200/squjs.vol19iss2pp21-28


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