title: Study for luminescence performance of three methyl xanthine derivatives.
abstract: In this paper, the low-temperature phosphorescence (LTP), the low-temperature fluorescence (LTF), the paper substrate room-temperature phosphorescence (PS-RTP) and the room fluorescence (RTF) properties of caffeine (CF), theophylline (TP), and theobromine (TB) are investigated and compared, and some rules are found out: their maximal excitation wavelength and emission wavelength are in the range of 270-300 nm and 395-445 nm, respectively. And the PS-RTP characters of lifetime, polarization and quanta yield are also investigated and compared. It is found that their lifetimes of PS-RTP are all in the level of 0.1s. They belong to long-life phosphorescence and their PS-RTP spectra are incompletely polarized.
authors.affiliation: Institute of Chemistry and Chemical Engineering, Shanxi University, Taiyuan 030006, PR China.
authors.forename: Yan-Li
authors.initials: YL
authors.lastname: Wei
authors.forename: Chuan
authors.initials: C
authors.lastname: Dong
authors.forename: Shao-Min
authors.initials: SM
authors.lastname: Shuang
authors.forename: Dian-Sheng
authors.initials: DS
authors.lastname: Liu
mesh_terms: D002110:Caffeine / Q000737:chemistry; D005453:Fluorescence; D006863:Hydrogen-Ion Concentration; D008163:Luminescent Measurements; D015394:Molecular Structure; D013050:Spectrometry, Fluorescence; D013696:Temperature; D013805:Theobromine / Q000737:chemistry; D013806:Theophylline / Q000737:chemistry; D014970:Xanthines / Q000737:chemistry*
chemical_list: D014970:Xanthines; C008514:methylxanthine; D002110:Caffeine; D013806:Theophylline; D013805:Theobromine