QUANTITATIVE STUDIES OF GROUND AND EXCITED-STATE CHARGE-TRANSFER COMPLEXES OF FULLERENES WITH N,N-DIMETHYLANILINE AND N,N-DIETHYLANILINE

A comprehensive spectroscopic study of ground state charge transfer complexes and exciplexes of C-60 and C-70 with N,N-diethylaniline (DEA) and N,N-dimethylaniline (DMA) is reported. The pure absorption spectra of ground state complexes and pure exciplex fluorescence spectra of C-60/C-70-DEA/DMA are determined by use of a chemometrics method principal component analysis-self modeling spectral resolution. The exciplex emissions are strongly solvent dependent. In room-temperature toluene, exciplex emissions are absent and the quenching of monomer fluorescence involves both dynamic and static processes. In room-temperature hexane, the quenching of monomer excited state is dominated by the formation of exciplexes. The observed dual fluorescence for C-60/C-70-DEA/DMA in hexane can be explained by a mechanism in which contributions from both prompt and delayed monomer emissions are considered.