Photophysical properties of diphenylacetylene derivatives in solution phase. IV. N,N-dimethylanilino(phenyl)acetylene in n-hexane

✍ Scribed by Yoshinori Hirata; Tadashi Okada; Tateo Nomoto

• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 408 KB
• Volume: 257
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(96)00590-8

✦ Synopsis

By using picosecond transient absorption and fluorescence lifetime measurement techniques, we have investigated the photophysical properties of N,N-dimethylanilino(phenyl)-acetylene in n-hexane solution. The lifetime of the second excited singlet state was determined to be about 20 ps at room temperature and a strong delayed S 2 fluorescence excited from S~ was observed. The characteristic features we observed seem to result from the accidental degeneracy of S 2 and S I. Introduction of the dimethylamino group makes the vibrational level density high and results in a large rate constant of internal conversion from S 2 to S t without excess vibrational energy.