Derivatized fullerenes bearing multiple electron donors: synthesis and charge transfer properties.
A series of methano-C60 adducts bearing up to six electron donating N,N-dimethylaniline units (denoted as D compounds), along with their analogues without the dimethylamino groups as references (R compounds), were synthesized. The redox properties of the D compounds in solutions were evaluated spectroscopically in reference to the R compounds. According to UV/vis absorption results, there are obviously ground-state intramolecular charge-transfer complexes in the D series, and the charge-transfer effects apparently become saturated with only two donor units in the molecule. The photoinduced intramolecular electron-transfer properties of the D compounds were investigated via fluorescence measurements. The emission from intramolecular exciplexes can be found only in the D molecule with two electron donor units. Throughout the D series, the fluorescence properties are highly sensitive to the solvent polarity, with the emission completely quenched for all of the molecules in a polar solvent like methylene chloride. Mechanistic implications of the results are discussed.
Li
Huaping
H
Department of Chemistry and Laboratory for Emerging Materials and Technology, Clemson University, Clemson, South Carolina 29634-0973, USA.
Huang
Weijie
W
Guo
Zhixin
Z
Guduru
Radhakishan
R
Sun
Ya-Ping
YP