Two emitting states of excited p-(9-anthryl)-n,n-dimethylaniline derivatives in polar solvents

✍ Scribed by Aleksander Siemiarczuk; Zbigniew R. Grabowski; Adam Krówczyński; Micha Asher; Michael Ottolenghi

• Publisher: Elsevier Science
• Year: 1977
• Tongue: English
• Weight: 582 KB
• Volume: 51
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(77)80411-9

✦ Synopsis

Steady-state and time-resolved fluorescence spectroscopy, as well as the S,, + St absorption spectra of three anthryl derivatives of dimethylaniline, I-III, reveal the existence of two emitting states in all these compounds. The primary locally excited (LE) state of the anthracenc moiety relaxes in polar solvents to a highly polar excited state. The relaxation involves most probably an internal rotation between the dialkylaniline donor and the anthracene acceptor structural sub-units, to reach a perpendicular conformation of the twisted internal charge-transfer (TICT) excited state. The intersystem crossing occurs preferentally in the TICT state, being followed by a back electron transfer rekxation to a lower lying LE triplet.