The room-temperature fluorescence and room-temperature phosphorescence quantum yields of the isomers of aminobenzoic acid adsorbed on sodium acetate were obtained. These data were correlated with solution fluorescence data and diffuse reflectance infrared spectral data from the three isomers. The results yielded insights into the bonding interactions of the aminobenzoic acid isomers with sodium acetate. In particular, the specific structural and bonding characteristics of the isomers with sodium acetate were very important in determining whether a high room-temperature phosphorescence quantum yield would be obtained from a given isomer.