Photosensitizers with high energy, long lasting charge-transfer states are important components in systems designed for solar energy conversion by multistep electron transfer. Here, we show that in a push-pull type, u-oxo-bridged porphyrin heterodimer composed of octaethylporphyrinatoaluminum(III) and octaethylporphyrinatophosphorus(V), the strong excitonic coupling between the porphyrins and the different electron withdrawing abilities of Al(III) and P(V) promote the formation of a high energy CT state. Using, an array of optical and magnetic resonance spectroscopic methods along with theoretical calculations, we demonstrate photodynamics of the heterodimer that involves the initial formation of a singlet CT which relaxes to a triplet CT state with a lifetime of ~130 ps. The high-energy triplet CT state (3CT = 1.68 eV) lasts for nearly 100 us prior relaxing to the ground state.

A Charge Transfer State Induced by Strong Exciton Coupling in a Cofacial mu-Oxo-bridged Porphyrin Heterodimer

Ciuti, Susanna
Investigation
;
Barbon, Antonio
Investigation
;
di Valentin, Marilena
Membro del Collaboration Group
;
van der Est, Art
Writing – Original Draft Preparation
;
2021

Abstract

Photosensitizers with high energy, long lasting charge-transfer states are important components in systems designed for solar energy conversion by multistep electron transfer. Here, we show that in a push-pull type, u-oxo-bridged porphyrin heterodimer composed of octaethylporphyrinatoaluminum(III) and octaethylporphyrinatophosphorus(V), the strong excitonic coupling between the porphyrins and the different electron withdrawing abilities of Al(III) and P(V) promote the formation of a high energy CT state. Using, an array of optical and magnetic resonance spectroscopic methods along with theoretical calculations, we demonstrate photodynamics of the heterodimer that involves the initial formation of a singlet CT which relaxes to a triplet CT state with a lifetime of ~130 ps. The high-energy triplet CT state (3CT = 1.68 eV) lasts for nearly 100 us prior relaxing to the ground state.
File in questo prodotto:
File Dimensione Formato  
Final_PCCP.pdf

accesso aperto

Descrizione: Articolo
Tipologia: Postprint (accepted version)
Licenza: Accesso gratuito
Dimensione 495.66 kB
Formato Adobe PDF
495.66 kB Adobe PDF Visualizza/Apri
Pubblicazioni consigliate

Caricamento pubblicazioni consigliate

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11577/3361172
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 11
  • ???jsp.display-item.citation.isi??? 10
social impact