Weak fluorescence from the S2(1Lb) state of biphenylene

✍ Scribed by H. Shizuka; T. Ogiwara; S. Cho; T. Morita

• Publisher: Elsevier Science
• Year: 1976
• Tongue: English
• Weight: 485 KB
• Volume: 42
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(76)80371-5

✦ Synopsis

Weak fluorescence from biphenylene has been observed in some solvents [A max: 480 IUT!, Qf" 1.0 {* 0.3) X 104} ctt 350 nm and 20"Cf. The fluorescence is assigned to Sz tL Lb) -t So ('A) by means of the fiuorescence polarizrttion method. The Sz fluorescence in cyc!ohexane was ~~ve~en~h-dependent-Rapid radiationless processes in excited biphenylene are also discussed. I. introduction The spectroscopic properties of biphenylene have been studied by several workers [l---8]. Two papers -[3,4] have described the observation of fluorescence from a higher excited electronic state in biphenylene, as well as long-lived phosphorescence from a higher triplet state.. However, Hochstrasser and McA@ine f5] showed that the previously reported dual emissions _ [3,4] are caused by an impurity that absorbs around 280 nm, and emits fluorescence at 300 nm and phosphorescence at 410 nm. Munro et al. [6] also reported