Catalogo Articoli (Spogli Riviste)

OPAC HELP

Titolo:
Modulating charge separation and charge recombination dynamics in porphyrin fullerene linked dyads and triads: Marcus-normal versus inverted region
Autore:
Imahori, H; Tamaki, K; Guldi, DM; Luo, CP; Fujitsuka, M; Ito, O; Sakata, Y; Fukuzumi, S;
Indirizzi:
Osaka Univ, CREST, Japan Sci & Technol Corp, Grad Sch Engn,Dept Mat & LifeSci, Suita, Osaka 5650871, Japan Osaka Univ Suita Osaka Japan 5650871 LifeSci, Suita, Osaka 5650871, Japan Tohoku Univ, Inst Chem React Sci, Aoba Ku, Sendai, Miyagi 9808577, Japan Tohoku Univ Sendai Miyagi Japan 9808577 Ku, Sendai, Miyagi 9808577, Japan Univ Notre Dame, Radiat Lab, Notre Dame, IN 46556 USA Univ Notre Dame Notre Dame IN USA 46556 iat Lab, Notre Dame, IN 46556 USA Osaka Univ, Inst Sci & Ind Res, Ibaraki, Osaka 5670047, Japan Osaka Univ Ibaraki Osaka Japan 5670047 Res, Ibaraki, Osaka 5670047, Japan
Titolo Testata:
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
fascicolo: 11, volume: 123, anno: 2001,
pagine: 2607 - 2617
SICI:
0002-7863(20010321)123:11<2607:MCSACR>2.0.ZU;2-H
Fonte:
ISI
Lingua:
ENG
Soggetto:
PHOTOINDUCED ELECTRON-TRANSFER; PHOTOSYNTHETIC REACTION-CENTER; FREE-ENERGY; INTRAMOLECULAR ELECTRON; ARTIFICIAL PHOTOSYNTHESIS; PHOTOPHYSICAL PROPERTIES; TRANSFER COMPLEXES; PHOTOELECTROCHEMICAL PROPERTIES; ELECTROCHEMICAL PROPERTIES; TEMPERATURE-DEPENDENCE;
Tipo documento:
Review
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Physical, Chemical & Earth Sciences
Citazioni:
133
Recensione:
Indirizzi per estratti:
Indirizzo: Imahori, H Osaka Univ, CREST, Japan Sci & Technol Corp, Grad Sch Engn,DeptMat & LifeSci, 2-2 Yamadaoka, Suita, Osaka 5650871, Japan Osaka Univ 2-2 Yamadaoka Suita Osaka Japan 5650871 50871, Japan
Citazione:
H. Imahori et al., "Modulating charge separation and charge recombination dynamics in porphyrin fullerene linked dyads and triads: Marcus-normal versus inverted region", J AM CHEM S, 123(11), 2001, pp. 2607-2617

Abstract

Photoinduced charge separation (CS) and charge recombination (CR) processes have been examined in various porphyrin-fullerene linked systems (i.e., dyads and triads) by means of time-resolved transient absorption spectroscopy and fluorescence lifetime measurements. The investigated compounds comprise a homologous series of rigidly linked linear donor-acceptor arrays with different donor-acceptor separations and diversified donor strength: freebase porphyrin-C-60 dyad (H2P-C-60) zincporphyrin-C-60 dyad (ZnP-C-60), ferrocene-zincporphyrin-C-60 triad (Fc-ZnP-C-60), ferrocene-freebase porphyrin-C-60 triad (Fc-H2P-C-60), and zincporphyrin-freebase porphyrin-C-60 triad (ZnP-H2P-C-60). Most importantly, the lowest lying charge-separated state of all the investigated systems; namely, that of ferrocenium ion (Fc(+)) and the C-60 radical anion (C60(.-)) pair in the Fc-ZnP-C-60 triad; has been generated with the highest quantum yields (close to unity) and reveals a lifetime as long as 16 mus. Determination of CS and CR rate constants, together with the one-electron different solvents, has allowed us to examine the driving redox potentials of the donor and acceptor moieties in force dependence (-DeltaG(ET)(0)) of the electron-transfer rate constants (k(ET)): Hereby,the semilogarithmic plots (i.e., log k(ET) versus -DeltaG(ET)(0)) lead to the evaluation of the reorganization energy (lambda) and the electronic coupling matrix element (V) in light of the Marcus theory of electron-transferreactions: lambda = 0.66 eV and V = 3.9 (-1) for ZnP-C-60 dyad and lambda = 1.09 eV and V = 0.019 cm(-1) for Fc-ZnP-C-60, Fc-H2P-C-60, and ZnP-H2P-C-60 triads. Interestingly, the Marcus plot in Fc-ZnP-C-60, FC-H2P-C-60, and ZnP-H2P-C-60 has provided clear evidence for intramolecular CR located in both the normal and inverted regions of the Marcus parabola. The coefficientfor the distance dependence of V (damping factor: beta (CR) = 0.58 Angstrom (-1)) is deduced which depends primarily on the nature of the bridging molecule.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 20/09/20 alle ore 06:59:55