Excitation versus Emission Spectra as a Means to Examine Selective Fluorescence Quenching Agents

Abstract

To ascertain whether fluorescence quenching is best studied with the use of excitation or emission spectra, and to expand our existing PAH spectral data file, we have recorded excitation spectra of benzo[b]perylene, dibenzo[hi,wx]heptacene, tetrabenzo[de,hi,mn,qr]naphthacene, perylene, benzo[a]fluoranthene, benzo[def]indeno[1,2,3hi]chrysene, naphtho[2,1a]fluoranthene, naphtho[2,3b]fluoranthene, benzo[k]fluoranthene, 2-azapyrene, naphtho[8,1,2hij]pyreno[9,10,1def]phthalazine, indeno[1,-2,3ij]isoquinoline, benzo(lmn][3,8]phenanthroline, and 7-methyldibenzo(b,def]chrysene at various nitromethane concentrations. Results of these measurements verify our earlier observations concerning the nitromethane selective quenching rule and further illustrate the importance of considering inner-filtering artifacts in quenching studies.