Kinetics of intramolecular electron transfer in binuclear (NC)5Fe(II)-CN-Co(III) chelate complexes by picosecond absorption spectroscopy

The rates of intramolecular electron transfer in the binuclear complexes (NC)5FeII-CN-CoIII(chelate) (where chelate = NBETA and HEDTA) have been measured directly using picosecond absorption spectroscopy. Excitation of the CoIII1T1g ← 1A1g band by a 530-nm 6-ps fwhm laser pulse is followed by rapid electron transfer from FeII resulting in FeIII, and CoII in the 2E state. The subsequent decay of FeIII occurs with a half-life of 150 ps. Our data indicate that the CoII2E state has ∼75-ps lifetime and experiences a low-spin to high-spin intersystem crossing to form the 4T1g ground state. The subsequent spin-permitted electron transfer back to the FeII species occurs in ∼95 ps. Curves calculated on the basis of this mechanism are in good agreement with the experimental data. © 1982, American Chemical Society. All rights reserved.

Kinetics of intramolecular electron transfer in binuclear (NC)5Fe(II)-CN-Co(III) chelate complexes by picosecond absorption spectroscopy Academic Article