Photoinduced hole transfer from the triplet state in a porphyrin-based donor-bridge-acceptor system
Journal article, 2003

The triplet excited-state deactivation of a gold porphyrin (AuP) in porphyrin-based donor-bridge-acceptor (D-B-A) systems has been studied. The results from room temperature and 80 K measurements are presented. The primary objectives have been to investigate whether electrons/electron holes or excitation energy could be transferred from (AuP)-Au-3 to the appended zinc porphyrin (ZnP) in the dimers. As the bridging chromophores in our D-B-A systems separate the ZnP and AuP moieties by 19 A edge-to-edge, we do not expect a significant contribution to either electron or energy transfer from a direct (through space) exchange mechanism. This gives us the opportunity to scrutinize how the bridging chromophores influence the transfer reactions. The results show that quenching of (AuP)-Au-3 occurs with high efficiency in the dimers that are connected by fully conjugated bridging chromophores, whereas no quenching is observed when the conjugation of the bridge is broken. We also observed that the decay of (AuP)-Au-3 is complex at temperatures below 110 K. In addition to the two previously published lifetimes on the order of some 10-100 mus, we have found a third lifetime on the nanosecond time scale.


Joakim Andreasson

Department of Physical Chemistry

Gerdenis Kodis

Arizona State University

Thomas Ljungdahl

Chalmers, Department of Chemistry and Bioscience, Organic Chemistry

A. L. Moore

Arizona State University

T. A. Moore

Arizona State University

D. Gust

Arizona State University

Jerker Mårtensson

Chalmers, Department of Chemistry and Bioscience, Organic Chemistry

Bo Albinsson

Department of Physical Chemistry

Journal of Physical Chemistry A

1089-5639 (ISSN) 1520-5215 (eISSN)

Vol. 107 42 8825-8833

Subject Categories

Physical Chemistry



More information