ROOM-TEMPERATURE PHOSPHORESCENCE OF SELECTED PTERIDINES

The phosphorescence properties of a number of pteridines were investigated at room temperature and 77 K. Most of the pteridines exhibit intense phosphorescence at 77 K, and several pteridines were found to exhibit weak phosphorescence at room temperature when alkaline solutions were spotted on filter paper and rigorously dried. The room temperature phosphorescence (RTP) emission from the pteridines was greatly enhanced when the compounds were adsorbed on sodium acetate impregnated paper. In fact, all of the pteridines which exhibit phosphorescence at 77 K show RTP when adsorbed on sodium acetate impregnated paper. Many of the pteridines show both RTP and an E-type delayed fluorescence emission. The external heavy atom effect was also investigated with several compounds. The results of our studies provide additional insight into the RTP phenomenon and indicate that the highly selective and sensitive RTP technique should prove quite useful for the analysis of pteridines in biological systems. © 1979, American Chemical Society. All rights reserved.