Blue-green photoluminescence from pyridine-C-60 adduct

The freshly prepared solution of C-60 in pyridine has a purple-pinkish colo r, which turns gradually into a brown color. We report for the first time t he observation of a bright blue-green photoluminescence from the brown C-60 /pyridine solution upon UV excitation. The luminescent species is identifie d to be the zwitterionic adduct formed between pyridine and C-60 as reveale d by IH-NMR, mass spectra, and the solvatochromic effect of the photolumine scence to protic solvent. The fluorescence excitation spectra of the lumine scent species and the dependence of the luminescence on excitation waveleng th are also reported. C-70 in pyridine shows similar phenomena. (C) 2000 El sevier Science B.V. All rights reserved.