Absorption spectroscopic study of EDA complexes of [70]fullerene with a series of methyl benzenes

[70]Fullerene has been shown to form 1:1 molecular complexes with toluene, p-xylene, m-xylene, 1,2,4,5-tetramethyl benzene (durene) and pentamethyl benzene (PMB) in CCl4 medium by absorption spectroscopic method. Isosbestic points have been detected in case of complexes with PMB and durene. Charge transfer absorption band could not be detected but the intensity of the broad absorption band of C-70 in CCl4 decreases systematically with increase in the concentration of the added methylbenzenes. From this trend the formation constants (K-c) of the complexes have been determined at three different wavelengths. The constancy of K-c with respect to change in the wavelength of measurement supports the view that complex of a single stoichiometry (1:1) is formed in each case. (C) 2001 Elsevier Science B.V. All rights reserved.