PHOTOINDUCED ELECTRON-TRANSFER IN ZINC PORPHYRIN-CROWN ETHER SUPRAMOLECULE WITH EU3-ACCEPTOR IN CROWN VOID( ELECTRON)

Citation
V. Krishnan et al., PHOTOINDUCED ELECTRON-TRANSFER IN ZINC PORPHYRIN-CROWN ETHER SUPRAMOLECULE WITH EU3-ACCEPTOR IN CROWN VOID( ELECTRON), Journal of photochemistry and photobiology. A, Chemistry, 84(3), 1994, pp. 233-235
Citations number
10
Categorie Soggetti
Chemistry Physical
ISSN journal
10106030
Volume
84
Issue
3
Year of publication
1994
Pages
233 - 235
Database
ISI
SICI code
1010-6030(1994)84:3<233:PEIZPE>2.0.ZU;2-I
Abstract
Photoinduced electron transfer (ET) reactions in the zinc porphyrin-cr own ether (ZnPCE) supramolecule, in which one crown ether moiety conta ining Eu3+ as electron acceptor is covalently linked to zinc porphyrin (ZnP), were studied by flash photolysis. In methanol solutions, highl y efficient charge separation occurs via intramolecular ET from (ZnP)- Zn-3 to Eu3+ encapsulated in the crown ether void (k(1) = (3 +/- 1) X 10(3) s(-1)) and intramolecular ET from 3ZnP to uncomplexed Eu2+ (k(2) = (2.5 +/- 0.5) X 10(3) s(-1)). Intermolecular ET from Eu2+ escaped f rom the crown ether void to ZnP.+ (k(tau) = (4.3 +/- 0.7) X 10(8) M(-1 ) s(-1)) seems to be the main pathway of charge recombination.