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Stergiou A, Gobeze HB, Petsalakis ID, Zhao S, Shinohara H, D'Souza F, Tagmatarchis N. Oligothiophene/graphene supramolecular ensembles managing light induced processes: preparation, characterization, and femtosecond transient absorption studies leading to charge-separation. Nanoscale 2015; 7:15840-15851. [PMID: 26358392 DOI: 10.1039/c5nr04875c] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Advances in organic synthetic chemistry combined with the exceptional electronic properties of carbon allotropes, particularly graphene, is the basis used to design and fabricate novel electron donor-acceptor ensembles with desired properties for technological applications. Thiophene-based materials, which are mainly thiophene-containing polymers, are known for their notable electronic properties. In this frame moving from polymer to oligomer forms, new fundamental information would help for a better understanding of their electrochemical and photophysical properties. Furthermore, a successful combination of their electronic properties with those of graphene is a challenging goal. In this study, two oligothiophene compounds, which consist of three and nine thiophene-rings and are abbreviated 3T and 9T, respectively, were synthesized and noncovalently associated with liquid phase exfoliated few-layered graphene sheets (abbreviated eG), thus forming donor-acceptor 3T/eG and 9T/eG nanoensembes. Markedly, intra-ensemble electronic interactions between the two components in the ground and excited states were evaluated with the aid of UV-Vis and photoluminescence spectroscopy. Furthermore, redox assays revealed the one-electron oxidation of 3T accompanied by one-electron reduction due to eG in 3T/eG, whereas there were two reversible one-electron oxidations of 9T accompanied by one-electron reduction of eG9T/eG. The electrochemical band gap for the 3T/eG and 9T/eG ensembles were calculated and verified, in which the negative free-energy change for the charge-separated state of 3T/eG and 9T/eGvia the singlet excited state of 3T and 9T, respectively, were thermodynamically favorable. Finally, the results of transient pump-probe spectroscopy studies at the femtosecond time scale were supportive of charge transfer type interactions in the 3T/eG and 9T/eG ensembles. The estimated rates for intra-ensemble charge separation were found to be 9.52 × 10(9) s(-1) and 2.2 × 10(11) s(-1), respectively, for 3T/eG and 9T/eG in THF, which reveal moderate to ultrafast photoinduced events in the oligothiophene/graphene supramolecular ensembles.
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Affiliation(s)
- A Stergiou
- Theoretical and Physical Chemistry Institute, National Hellenic Research Foundation, 48 Vassileos Constantinou Avenue, Athens 11635, Greece.
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Petsalakis ID, Georgiadou DG, Vasilopoulou M, Pistolis G, Dimotikali D, Argitis P, Theodorakopoulos G. Theoretical Investigation on the Effect of Protonation on the Absorption and Emission Spectra of Two Amine-Group-Bearing, Red “Push−Pull” Emitters, 4-Dimethylamino-4′-nitrostilbene and 4-(dicyanomethylene)-2-methyl-6-p-(dimethylamino) styryl-4H-pyran, by DFT and TDDFT Calculations. J Phys Chem A 2010; 114:5580-7. [DOI: 10.1021/jp100338d] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- I. D. Petsalakis
- Theoretical and Physical Chemistry Institute, The National Hellenic Research Foundation, 48 Vassileos Constantinou Avenue, 116 35 Athens, Greece, Institute of Microelectronics and Institute of Physical Chemistry, NCSR Demokritos, 153 10 Aghia Paraskevi, Greece, and Department of Chemical Engineering, National Technical University of Athens, 15780 Athens, Greece
| | - D. G Georgiadou
- Theoretical and Physical Chemistry Institute, The National Hellenic Research Foundation, 48 Vassileos Constantinou Avenue, 116 35 Athens, Greece, Institute of Microelectronics and Institute of Physical Chemistry, NCSR Demokritos, 153 10 Aghia Paraskevi, Greece, and Department of Chemical Engineering, National Technical University of Athens, 15780 Athens, Greece
| | - M. Vasilopoulou
- Theoretical and Physical Chemistry Institute, The National Hellenic Research Foundation, 48 Vassileos Constantinou Avenue, 116 35 Athens, Greece, Institute of Microelectronics and Institute of Physical Chemistry, NCSR Demokritos, 153 10 Aghia Paraskevi, Greece, and Department of Chemical Engineering, National Technical University of Athens, 15780 Athens, Greece
| | - G. Pistolis
- Theoretical and Physical Chemistry Institute, The National Hellenic Research Foundation, 48 Vassileos Constantinou Avenue, 116 35 Athens, Greece, Institute of Microelectronics and Institute of Physical Chemistry, NCSR Demokritos, 153 10 Aghia Paraskevi, Greece, and Department of Chemical Engineering, National Technical University of Athens, 15780 Athens, Greece
| | - D. Dimotikali
- Theoretical and Physical Chemistry Institute, The National Hellenic Research Foundation, 48 Vassileos Constantinou Avenue, 116 35 Athens, Greece, Institute of Microelectronics and Institute of Physical Chemistry, NCSR Demokritos, 153 10 Aghia Paraskevi, Greece, and Department of Chemical Engineering, National Technical University of Athens, 15780 Athens, Greece
| | - P. Argitis
- Theoretical and Physical Chemistry Institute, The National Hellenic Research Foundation, 48 Vassileos Constantinou Avenue, 116 35 Athens, Greece, Institute of Microelectronics and Institute of Physical Chemistry, NCSR Demokritos, 153 10 Aghia Paraskevi, Greece, and Department of Chemical Engineering, National Technical University of Athens, 15780 Athens, Greece
| | - G. Theodorakopoulos
- Theoretical and Physical Chemistry Institute, The National Hellenic Research Foundation, 48 Vassileos Constantinou Avenue, 116 35 Athens, Greece, Institute of Microelectronics and Institute of Physical Chemistry, NCSR Demokritos, 153 10 Aghia Paraskevi, Greece, and Department of Chemical Engineering, National Technical University of Athens, 15780 Athens, Greece
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Petsalakis ID, Theodorakopoulos G, Wright JS, Hamilton IP. Potential energy surface for large‐amplitude motion and vibrational spacings for FH+2. J Chem Phys 1990. [DOI: 10.1063/1.458566] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- I. D. Petsalakis
- Department of Chemistry, Carleton University, Ottawa, Ontario K1S 5B6, Canada
| | - G. Theodorakopoulos
- Department of Chemistry, Carleton University, Ottawa, Ontario K1S 5B6, Canada
| | - J. S. Wright
- Department of Chemistry, Carleton University, Ottawa, Ontario K1S 5B6, Canada
| | - I. P. Hamilton
- Department of Chemistry, University of Ottawa, Ottawa, Ontario K1N 6N5, Canada
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