A Supramolecular tetrad featuring covalently linked ferrocene-zinc porphyrin-BODIPY coordinated to fullerene: a charge stabilizing, photosynthetic antenna-reaction center mimic

No Thumbnail Available
Authors
Lim, Gary N.
Maligaspe, Eranda
Zandler, Melvin E.
D'Souza, Francis
Advisors
Issue Date
2014-12-15
Type
Article
Keywords
Artificial photosynthesis , BODIPY , Charge stabilization , Ferrocene , Fullerenes , Electron transfer , Zinc porphyrin
Research Projects
Organizational Units
Journal Issue
Citation
Lim, Gary N.; Maligaspe, Eranda; Zandler, Melvin E.; D'Souza, Francis. 2014. A Supramolecular tetrad featuring covalently linked ferrocene-zinc porphyrin-BODIPY coordinated to fullerene: a charge stabilizing, photosynthetic antenna-reaction center mimic. Chemistry - A European Journal, vol. 20:no. 51:pp 17089–17099
Abstract

A novel photosynthetic-antenna-reaction-center model compound, comprised of BF2-chelated dipyrromethene (BODIPY) as an energy-harvesting antenna, zinc porphyrin (ZnP) as the primary electron donor, ferrocene (Fc) as a hole-shifting agent, and phenylimidazole-functionalized fulleropyrrolidine (C(60)Im) as an electron acceptor, has been synthesized and characterized. Optical absorption and emission, computational structure optimization, and cyclic voltammetry studies were systematically performed to establish the role of each entity in the multistep photochemical reactions. The energy-level diagram established from optical and redox data helped identifying different photochemical events. Selective excitation of BODIPY resulted in efficient singlet energy transfer to the ZnP entity. Ultrafast electron transfer from the (ZnP)-Zn-1* (formed either as a result of singletsinglet energy transfer or direct excitation) or C-1(60)* of the coordinated fullerene resulting into the formation of the Fc-(C-60(-) Im: ZnPC+)-BODIPY radical ion pair was witnessed by femtosecond transient absorption studies. Subsequent hole migration to the ferrocene entity resulted in the Fc(+)-(C-60(+) Im: ZnP)-BODIPY radical ion pair that persisted for 7-15 ms, depending upon the solvent conditions and contributions from the triplet excited states of ZnP and ImC(60), as revealed by the nanosecond transient spectral studies. Better utilization of light energy in generating the long-lived charge-separated state with the help of the present "antenna- reaction-center" model system has been successfully demonstrated.

Table of Contents
Description
Click on the DOI link to access the article (may not be free).
Publisher
WILEY-VCH Verlag GmbH & Co.
Journal
Book Title
Series
Chemistry - A European Journal;v.20:no.51
PubMed ID
DOI
ISSN
0947-6539
EISSN