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Silicon‐Phthalocyanine‐Cored Fullerene Dendrimers: Synthesis and Prolonged Charge‐Separated States with Dendrimer Generations
Author(s) -
ElKhouly Mohamed E.,
Kang Eui Su,
Kay KwangYol,
Choi Chan Soo,
Aaraki Yasuyuki,
Ito Osamu
Publication year - 2007
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.200601254
Subject(s) - photochemistry , ultrafast laser spectroscopy , dendrimer , fullerene , phthalocyanine , absorption (acoustics) , nanosecond , silicon , materials science , chemistry , laser , optoelectronics , nanotechnology , organic chemistry , polymer chemistry , optics , physics , composite material
Silicon‐phthalocyanine‐cored fullerodendrimers with up to eight fullerene substituents (SiPc– n C 60 ; n =2, 4, and 8) have been synthesized. Photophysical properties of newly synthesized SiPc– n C 60 have been investigated by time‐resolved fluorescence and transient absorption analysis with pulsed laser light. Laser photolysis measurements suggest the occurrence of a charge‐separation process from 1 SiPc* to the C 60 subunits. The nanosecond transient absorption spectra in the near‐IR region indicate that the lifetimes of the formed radical ion pairs are prolonged on the order of SiPc–8 C 60 >SiPc–4 C 60 >SiPc–2 C 60 , which may be related to the electron migration among the C 60 subunits. The usefulness of SiPc– n C 60 as light‐harvesting systems, evaluated as a ratio of the rates of charge recombination to those of charge separation, increases markedly with the dendrimer generation.