Emission from Charge Recombination during the Pulse Radiolysis of 9-Cyano-10-phenylethynylanthracenes with Donor and Acceptor Substituents
Resource
Journal of Organic Chemistry 71 (23): 8732-8739
Journal
Journal of Organic Chemistry
Journal Volume
71
Journal Issue
23
Pages
8732-8739
Date Issued
2006
Date
2006
Author(s)
Samori, Shingo
Tojo, Sachiko
Fujitsuka, Mamoru
Liang, Hua-Jyu
Ho, Tong-Ing
Majima, Tetsuro
Abstract
Emission from 9-cyano-10-phenylanthracene and 9-cyano-10-phenylethynylanthracenes having donor and acceptor substituents (RA = PA, PEA, OEA, NEA, and DEA) was studied with the time-resolved fluorescence measurement during the pulse radiolysis of RAs in benzene (Bz). PA and DEA showed only monomer emission, while other RAs (PEA, OEA, and NEA) showed both monomer and excimer emissions with much lower intensities. On the basis of the steady-state and transient absorption and emission measurements, the formation of RA in the singlet excited state ((1)RA*) can be attributed to the charge recombination between RA radical cation and anion (RA*+ and RA*-, respectively) which are initially generated from the radiolytic reaction in Bz. It is expected that for PA with a twisted geometry, the charge recombination between PA*+ and PA*- occurs to give (1)PA* during the pulse radiolysis in Bz. For PEA and OEA, pi-stacking interaction is possible for the formation of an encounter complex during the charge recombination between RA*+ and RA*-. For NEA, it is expected that NEA*+ and NEA*- collide neck-to-neck to generate the excimer due to the twisted geometry. For DEA, a considerably twisted structure is assumed to give (1)DEA* with strong ICT character but not (1)(DEA)2* because of the bulky donor substituent.
Type
journal article
File(s)![Thumbnail Image]()
Loading...
Name
12.pdf
Size
380.27 KB
Format
Adobe PDF
Checksum
(MD5):4b7afd8f1c6820011327471b08c8951a