Synthesis and Spectroscopic Studies of New Bis(n-1 6-Di Complexes and Their Oxidation With PbO2

Abstract

A series of new bis(N-( 1-OH-2,6-di-tert-butylphenyl)salicylaldiminato)cobalt(II) complexes possessing one or two HO- and CH3O- substituents on the salicylaldehyde moiety were prepared, and their spectroscopic properties as well as oxidation with PbO2 were examined. ESR data indicate that oxidation of the complexes produces stable phenoxyl radicals. All phenoxyl radicals have similar g-values and hyperfine coupling constants, which were less influenced by the substituents and coordination. The experimental observations indicate that some Co(L-x)(2) radical ligand complexes are ligand-localized and there is not much contribution From the metal d-orbitals to the values of the g-factors. We were also able to observe satellite peaks from the C-13 nuclei in the aromatic ring. ESR spectra of some complexes during the time showed the partial conversion of primary radicals to secondary paramagnetic species exhibiting interaction of the radical center with Co-59(I= 7/2) and N-14 nuclei.