Photoinduced energy and electron transfer in porphyrin-anthraquinone dyads bridged with a triazine group

Abstract Porphyrin-anthraquinone dyads containing a triazine group as linker were synthesized and characterized by 1 H NMR, UV–visible, fluorescence and transient spectra and ESI-MS. Absorption spectra revealed that there was no appreciable interaction between the ground-state porphyrin moiety and the ground-state anthraquinone moiety. Fluorescence spectra illustrated that energy transfer takes place from the excited anthraquinone moiety to the porphyrin moiety when excited at 250 nm, whilst efficient electron transfer occurs from the singlet excited porphyrin moiety to the anthraquinone moiety in the case of excitation at 420 nm. A long-lived, charge-separated state H 2 P + –EQ − was observed by transient absorption spectra with a lifetime of 1.42 μs and 1.33 μs. These photochemical events were explained from electrochemical studies and suggest that the compounds have the ability to simulate electron transfer from chlorophylls to electron acceptors.

[1]  Yoshiteru Sakata,et al.  Sequential Energy and Electron Transfer in an Artificial Reaction Center: Formation of a Long-Lived Charge-Separated State , 2000 .

[2]  Rudolph A. Marcus,et al.  Electron Transfer Reactions in Chemistry: Theory and Experiment (Nobel Lecture) , 1993 .

[3]  H. Imahori,et al.  Control of electron transfer and its utilization , 1997 .

[4]  A. Melamed,et al.  Molecular Structures of Porphyrin−Quinone Models for Electron Transfer , 1996 .

[5]  J. S. Connolly,et al.  Charge-transfer emission in meso-linked zinc porphyrin-anthraquinone molecules , 1992 .

[6]  D. D. Perrin,et al.  Purification of laboratory chemicals , 1966 .

[7]  S. Fukuzumi,et al.  Novel photocatalytic function of porphyrin-modified gold nanoclusters in comparison with the reference porphyrin compound , 2003 .

[8]  Kevin M. Smith,et al.  Synthesis and reactions of meso-(p-nitrophenyl)porphyrins , 2004 .

[9]  C. Kirmaier,et al.  Optical properties of metalloporphyrin excited states , 1989 .

[10]  S. Fukuzumi,et al.  Hydrogen bonds not only provide a structural scaffold to assemble donor and acceptor moieties of zinc porphyrin-quinone dyads but also control the photoinduced electron transfer to afford the long-lived charge-separated states. , 2005, The journal of physical chemistry. B.

[11]  Guifeng Li,et al.  Hydrogen bonding effects on the surface structure and photoelectrochemical properties of nanostructured SnO2 electrodes modified with porphyrin and fullerene composites. , 2005, The journal of physical chemistry. B.

[12]  M. Zandler,et al.  Studies on Covalently Linked Porphyrin−C60 Dyads: Stabilization of Charge-Separated States by Axial Coordination , 2002 .

[13]  M. Zandler,et al.  Energy transfer followed by electron transfer in a supramolecular triad composed of boron dipyrrin, zinc porphyrin, and fullerene: a model for the photosynthetic antenna-reaction center complex. , 2004, Journal of the American Chemical Society.

[14]  B. Röder,et al.  Electron donor–acceptor compounds: exploiting the triptycene geometry for the synthesis of porphyrin quinone diads, triads, and a tetrad , 2001 .

[15]  Y. Wan,et al.  Dimethylformamide as a carbon monoxide source in fast palladium-catalyzed aminocarbonylations of aryl bromides. , 2002, The Journal of organic chemistry.

[16]  V. Balzani,et al.  Bimolecular electron transfer reactions of the excited states of transition metal complexes , 1978 .

[17]  Daoben Zhu,et al.  Fullerene–fluorescein–anthracene hybrids: a model for artificial photosynthesis and solar energy conversion , 2004 .

[18]  I. Tabushi,et al.  Efficient intramolecular quenching and electron transfer in tetraphenylporphyrin attached with benzoquinone or hydroquinone as a photosystem model , 1979 .

[19]  J. S. Connolly,et al.  Intramolecular photochemical electron transfer. 4. Singlet and triplet mechanisms of electron transfer in a covalently linked porphyrin-amide-quinone molecule , 1988 .

[20]  B. Maiya,et al.  Fluorescence studies on a supramolecular porphyrin bearing anthracene donor moieties , 1995 .

[21]  O. Ito,et al.  Conformation effect of oligosilane linker on photoinduced electron transfer of tetrasilane-linked zinc porphyrin–[60]fullerene dyads , 2007 .

[22]  D. Schuster,et al.  Synthesis and photophysics of porphyrin–fullerene donor–acceptor dyads with conformationally flexible linkers , 2006 .

[23]  J. S. Connolly,et al.  Intramolecular photochemical electron transfer. 2. Fluorescence studies of linked porphyrin-quinone compounds , 1983 .

[24]  J. E. Hanson,et al.  Weak temperature dependence of electron transfer rates in fixed-distance porphyrin-quinone model systems , 1994 .

[25]  Robert E. Belford,et al.  Efficient Multistep Photoinitiated Electron Transfer in a Molecular Pentad , 1990, Science.

[26]  I. Yamazaki,et al.  Photosynthetic electron transfer using fullerenes as novel acceptors , 2000 .

[27]  P. Loach,et al.  Syntheses of covalently‐linked porphyrin‐quinone complexes , 1980 .

[28]  T. Moore,et al.  Ultrafast Photoinduced Electron Transfer in Rigid Porphyrin—Quinone Dyads , 1995 .