Time-resolved resonance Raman spectra of octaethylporphinato copper(II) in the lowest excited triplet state

Abstract Time-resolved resonance Raman spectra were observed with the pump/probe technique using two 7 ns pulsed lasers for octaethylporphinato Cu(II) [(OEP)Cu] and its isotopomers (OEP-meso- d 4 and OEP- 15 N) in the lowest excited triplet state. Raman bands were assigned on the basis of depolarization ratios and isotope shifts. Then ν 2 , ν 3 and ν 4 modes of the macrocycle in the T 1 state were shifted to lower frequencies by 7, 37 and 57 cm −1 , respectively, compared with those of the ground state, but the peripheral ethyl internal modes were shifted little. The porphyrin skeletal modes exhibited significant broadening in the T 1 state but the ethyl modes did not.