http://www.cnr.it/ontology/cnr/individuo/prodotto/ID184468
Excited-State Absorption and Ultrafast Relaxation Dynamics of Porphyrin, Diprotonated Porphyrin, and Tetraoxaporphyrin Dication (Articolo in rivista)
- Type
- Label
- Excited-State Absorption and Ultrafast Relaxation Dynamics of Porphyrin, Diprotonated Porphyrin, and Tetraoxaporphyrin Dication (Articolo in rivista) (literal)
- Anno
- 2008-01-01T00:00:00+01:00 (literal)
- Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#doi
- 10.1021/jp710132s (literal)
- Alternative label
Agnese Marcelli; Paolo Foggi; Laura Moroni; Cristina Gellini; Pier Remigio Salvi (2008)
Excited-State Absorption and Ultrafast Relaxation Dynamics of Porphyrin, Diprotonated Porphyrin, and Tetraoxaporphyrin Dication
in The journal of physical chemistry. A
(literal)
- Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#autori
- Agnese Marcelli; Paolo Foggi; Laura Moroni; Cristina Gellini; Pier Remigio Salvi (literal)
- Pagina inizio
- Pagina fine
- Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#numeroVolume
- Rivista
- Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#numeroFascicolo
- Note
- ISI Web of Science (WOS) (literal)
- Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#affiliazioni
- Laboratorio Europeo di Spettroscopie non Lineari (LENS), Universita´ di Firenze;
Dipartimento di Chimica, Universita´ di Perugia;
INO-CNR;
Dipartimento di Chimica, Universita´ di Firenze. (literal)
- Titolo
- Excited-State Absorption and Ultrafast Relaxation Dynamics of Porphyrin, Diprotonated Porphyrin, and Tetraoxaporphyrin Dication (literal)
- Abstract
- The relaxation dynamics of unsubstituted porphyrin (H2P), diprotonated porphyrin (H4P2+), and tetraoxaporphyrin
dication (TOxP2+) has been investigated in the femtosecond-nanosecond time domain upon
photoexcitation in the Soret band with pulses of femtosecond duration. By probing with spectrally broad
femtosecond pulses, we have observed transient absorption spectra at delay times up to 1.5 ns. The kinetic
profiles corresponding with the band maxima due to excited-state absorption have been determined for the
three species. Four components of the relaxation process are distinguished for H2P: the unresolvably short
B f Qy internal conversion is followed by the Qy f Qx process, vibrational relaxation, and thermalization in
the Qx state with time constant ?150 fs, 1.8 ps, and 24.9 ps, respectively. Going from H2P to TOxP2+, two
processes are resolved, i.e., B f Q internal conversion and thermal equilibration in the Q state. The B f Q
time constant has been determined to be 25 ps. The large difference with respect to the B f Qy time constant
of H2P has been related to the increased energy gap between the coupled states, 9370 cm-1 in TOxP2+ vs
6100 cm-1 in H2P. The relaxation dynamics of H4P2+ has a first ultrafast component of ?300 fs assigned as
internal conversion between the B (or Soret) state and charge-transfer (CT) states of the H4P2+ complex with
two trifluoroacetate counterions. This process is followed by internal CT f Q conversion (time constant 9
ps) and thermalization in the Q state (time constant 22 ps). (literal)
- Prodotto di
- Autore CNR
- Insieme di parole chiave
Incoming links:
- Autore CNR di
- Prodotto
- Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#rivistaDi
- Insieme di parole chiave di