| Content Provider |
World Health Organization (WHO)-Global Index Medicus |
| Author |
Sudhakar, Kolanu Gokulnath, Sabapathi Giribabu, Lingamallu Lim, Gary N. Trâm, Ta D'Souza, Francis |
| Description |
Country affiliation: India Author Affiliation: Sudhakar K ( Inorganic & Physical Chemistry Division, CSIR-Indian Institute of Chemical Technology, Habsiguda, Hyderabad, 500007, Telangana, India.); Gokulnath S ( Inorganic & Physical Chemistry Division, CSIR-Indian Institute of Chemical Technology, Habsiguda, Hyderabad, 500007, Telangana, India.); Giribabu L ( Inorganic & Physical Chemistry Division, CSIR-Indian Institute of Chemical Technology, Habsiguda, Hyderabad, 500007, Telangana, India. giribabu.iict@gov.in.); Lim GN ( Department of Chemistry, University of North Texas, 1155â
Union Circle, #305070, Denton, TX, 76203-5017, USA.); Trâm T ( Department of Chemistry, University of North Texas, 1155â
Union Circle, #305070, Denton, TX, 76203-5017, USA.); D'Souza F ( Department of Chemistry, University of North Texas, 1155â
Union Circle, #305070, Denton, TX, 76203-5017, USA. francis.dsouza@unt.edu.) |
| Abstract |
Closely positioned donor-acceptor pairs facilitate electron- and energy-transfer events, relevant to light energy conversion. Here, a triad system TPACor-C60 , possessing a free-base corrole as central unit that linked the energy donor triphenylamine (TPA) at the meso position and an electron acceptor fullerene (C60) at the ß-pyrrole position was newly synthesized, as were the component dyads TPA-Cor and Cor-C60. Spectroscopic, electrochemical, and DFT studies confirmed the molecular integrity and existence of a moderate level of intramolecular interactions between the components. Steady-state fluorescence studies showed efficient energy transfer from (1) TPA* to the corrole and subsequent electron transfer from (1) corrole* to fullerene. Further studies involving femtosecond and nanosecond laser flash photolysis confirmed electron transfer to be the quenching mechanism of corrole emission, in which the electron-transfer products, the corrole radical cation (Cor(â
+) in Cor-C60 and TPA-Cor(â
+) in TPACor-C60) and fullerene radical anion (C60(â
-)), could be spectrally characterized. Owing to the close proximity of the donor and acceptor entities in the dyad and triad, the rate of charge separation, kCS , was found to be about 10(11) â
s(-1), suggesting the occurrence of an ultrafast charge-separation process. Interestingly, although an order of magnitude slower than kCS , the rate of charge recombination, kCR , was also found to be rapid (kCR ≈10(10) â
s(-1)), and both processes followed the solvent polarity trend DMF>benzonitrile>THF>toluene. The charge-separated species relaxed directly to the ground state in polar solvents while in toluene, formation of (3) corrole* was observed, thus implying that the energy of the charge-separated state in a nonpolar solvent is higher than the energy of (3) corrole* being about 1.52â
eV. That is, ultrafast formation of a high-energy charge-separated state in toluene has been achieved in these closely spaced corrole-fullerene donor-acceptor conjugates. |
| File Format |
HTM / HTML |
| ISSN |
18614728 |
| Issue Number |
12 |
| Journal |
Chemistry - An Asian Journal |
| Volume Number |
10 |
| e-ISSN |
1861471X |
| Language |
English |
| Publisher |
Wiley-VCH |
| Publisher Date |
2015-12-01 |
| Publisher Place |
Germany |
| Access Restriction |
One Nation One Subscription (ONOS) |
| Subject Keyword |
Discipline Chemistry |
| Content Type |
Text |
| Resource Type |
Article |
| Subject |
Organic Chemistry Biochemistry |
