Spectroscopic Properties of Polycyclic Aromatic Hydrocarbons: Effect of Solvent Polarity on the Fluorescence Emission Behavior of Select Fluoranthene, Fluorenochrysene, Indenochrysene, and Indenopyrene Derivatives

Fluorescence emission behavior is reported for benz[def]indeno-[1,2,3hi]chrysene, fluoreno[2,3,4,9defg]chrysene, benz[def]indeno-[l,2,3qr]chrysene, dibenzo[a,e]fluoranthene, indeno[1,2,3cd]pyrene, naphtho[1,2b]fluoranthene, benzo[b]fluoranthene, fluoranthene, benzo-[ghi]fluoranthene, naphtho[2,1a]fluoranthene, naphtho[2,3b]fiuoranthene, benzo[k]fluoranthene, and benzo[j]fluoranthene dissolved in organic nonelectrolyte solvents of varying polarity. Results of these measurements are used to classify the various solutes as either probe or nonprobe molecules, depending upon whether measured emission intensity ratios vary systematically with solvent polarity. Also discussed are primary and secondary inner-filtering artifacts associated with selective quenching agents used to help identify/analyze polycyclic aromatic hydrocarbons (PAHs) in unknown mixtures. Inner-filtering artifacts are illustrated by examining fluorescence emission intensities of 13 “nonalternant” PAHs at different nitromethane concentrations and solution absorbances.