Naslov
Excited-state absorption and ultrafast relaxation dynamics of protoporphyrin IX and hemin

Autori
Marcelli, Agnese ; Jelovica Badovinac, Ivana ; Orlić, Nada ; Remigio Salvi, Pier ; Gellini, Cristina

Izvornik
Photochemical & photobiological sciences (1474-905X) 12 (2013); 348-355

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
porphyrins; UV-vis ultrafast spectroscopy; relaxation pathway

Sažetak
The transient evolution of protoporphyrin IX (PPIX) and hemin following the Soret band excitation was measured in the 410–600 nm spectral region with sub-picosecond time resolution. In PPIX the relaxation pathway was characterized in the femto- and picosecond time scale by two processes with time constants of 350 fs and ∼6 ps, describing the evolution of the system through internal Qy → Qx conversion and vibrational relaxation and cooling in the Qx state. The lifetime of the Qx state was found to be 10.4 ns by time resolved fluorescence measurements. In hemin, the ground state is completely recovered in tens of picoseconds through pathways involving CT and (d, d) states. The experimentally observed vibrational dynamics is mainly due to “hot” ground state transitions.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

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