48 research outputs found
A photoluminescence study of C60 and C70
The luminescence spectra of C60 and C70 have been recorded in glassy toluene solution at 77 K and as neat solids at 5 K. The C70 spectrum consists of two band systems each with resolved vibronic structure. The red system of C70 begins at 15012 cm-1, exhibits a lifetime of 1 --> S0 fluorescence. The infrared emission system begins at 12614 cm-1, decays with a 30 ms lifetime and is assigned as T1 --> S0 phosphorescence. A weak luminescence maximum at 13579 cm-1 is assigned tentatively as the S1 --> S0 fluorescence of C60.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/30243/1/0000638.pd
A Molecular Thermometer Based on the Delayed Fluorescence of C70 Dispersed in a Polystyrene Film
A PHOTOLUMINESCENCE STUDY OF AND
Author Institution: Department of Chemistry, The University of MichiganSince their discovery, there has been considerable interest in the spectroscopic characterization of fullerenes, in particular the (Buckminsterfullerene) and forms that may be produced in reasonable yields using a method described by Kratschmer et al. Arbogast et al. determined a number of important photophyscial properties of in hexane and benzene solutions, but were unable to detect either fluorescence or phosphorescence from at room temperature. However, a triplet state was detected by triplet-triplet transient absorption measurements, and photoquenching studies placed the triplet state energy between 11,500 and . We have obtained luminescence spectra of and in glassy toluene solution at 77K and as neat solids at 5K. The spectrum consists of two band systems each with resolved vibronic structure. The red system of begins at , exhibits a lifetime of sec and is assigned as fluorescence. The infrared emission system begins at , decays with a 30 msec. lifetime and is assigned as phosphorescence. Several Raman modes are observed as combination bands in the infrared system. However, all of the prominent features cannot be assigned to a single, orbitally allowed transition."