ESR study of light-induced valence tautomerism of a Co mononuclear complex: [Co(phen)(3,5-DTBSQ)(3,5-DTBCat)]

Light-induced valence tautomarism (LIVT) of [Co(phen)(3,5-DTBSQ)(3,5-DTBCat)] (1) was investigated by ESR of the semiquinonate radical both in powder sample and in glass matrix. The ESR signal decay and the relaxation in the glass matrixes were well analyzed by double exponential fitting, indicating the possibility of two-step mechanism.