1
|
Li X, Wang YL, Chen C, Han YF. Luminescent Crystalline Carbon- and Nitrogen-Centered Organic Radicals Based on N-Heterocyclic Carbene-Triphenylamine Hybrids. Chemistry 2023; 29:e202203242. [PMID: 36331436 DOI: 10.1002/chem.202203242] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 11/02/2022] [Accepted: 11/04/2022] [Indexed: 11/06/2022]
Abstract
Developing luminescent radicals with tunable emission is a challenging task due to the limitation of alternative skeletons. Herein, a series of carbene-triphenylamine hybrids were prepared by the direct C2-arylation of N-heterocyclic carbenes with 4-bromo-N,N-bis(4-methoxyphenyl)aniline. These hybrids showed multiple redox-active properties and could be converted to carbon-centered luminescent radicals with blue-to-cyan emissions (λmax : 436-486 nm) or nitrogen-centered luminescent radicals with orange emissions (λmax : 590-623 nm) through chemical reduction or oxidation, respectively. The radical species were characterized by electron paramagnetic resonance spectroscopy, ultraviolet-visible spectroscopy, and single-crystal X-ray diffractometry analysis. Notably, the corresponding nitrogen-centered radicals exhibited good stability in atmospheric air, and their thermal decomposition temperatures were determined to be above 200 °C. In addition, spectral and theoretical calculations indicate that all radicals exhibit anti-Kasha emissions.
Collapse
Affiliation(s)
- Xin Li
- Key Laboratory of Synthetic and, Natural Functional Molecule of the Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi'an, 710127, P. R. China
| | - Yi-Lin Wang
- Key Laboratory of Synthetic and, Natural Functional Molecule of the Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi'an, 710127, P. R. China
| | - Can Chen
- Key Laboratory of Synthetic and, Natural Functional Molecule of the Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi'an, 710127, P. R. China
| | - Ying-Feng Han
- Key Laboratory of Synthetic and, Natural Functional Molecule of the Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi'an, 710127, P. R. China
| |
Collapse
|
2
|
Hattori Y, Tsubaki S, Matsuoka R, Kusamoto T, Nishihara H, Uchida K. Expansion of Photostable Luminescent Radicals by Meta-Substitution. Chem Asian J 2021; 16:2538-2544. [PMID: 34270166 DOI: 10.1002/asia.202100612] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 07/15/2021] [Indexed: 11/12/2022]
Abstract
Polychlorinated pyridyldiphenylmethyl radicals having substituents meta to the position bearing the carbon-centered radical (α-carbon) are synthesized. All of them are stable in ambient conditions in solutions and fluorescent in cyclohexane. The fluorescence of the radicals with bromo, phenyl, 4-chlorophenyl, or 2-pyridyl substituents are enhanced in chloroform, while the emission of the radicals with 2-thienyl or 2-furyl substituents are quenched in chloroform. DFT and TD-DFT calculations indicate that the first doublet excited states of the former are locally excited, while the first doublet excited states of the latter are charge transfer states from the π-electron-donating substituent to the accepting radical. The latter also show much higher photostability under 370-nm light irradiation compared with the first reported photostable fluorescent radical, (3,5-dichloro-4-pyridyl)bis(2,4,6-trichlorophenyl)methyl radical (PyBTM), with pronounced bathochromic shifts of the fluorescence.
Collapse
Affiliation(s)
- Yohei Hattori
- Materials Chemistry Course, Faculty of Advanced Science and Technology, Ryukoku University, Seta, Otsu, Shiga, 520-2194, Japan
| | - Shunsuke Tsubaki
- Materials Chemistry Course, Faculty of Advanced Science and Technology, Ryukoku University, Seta, Otsu, Shiga, 520-2194, Japan
| | - Ryota Matsuoka
- Department of Life and Coordination-Complex Molecular Science, Instite for Molecular Science, 5-1 Higashiyama, Myodaiji, Okazaki, Aichi, 444-8787, Japan
| | - Tetsuro Kusamoto
- Department of Life and Coordination-Complex Molecular Science, Instite for Molecular Science, 5-1 Higashiyama, Myodaiji, Okazaki, Aichi, 444-8787, Japan
| | - Hiroshi Nishihara
- Research Institute for Science and Technology, Tokyo University of Science, 2641, Yamazaki, Noda, Chiba, 278-8510, Japan
| | - Kingo Uchida
- Materials Chemistry Course, Faculty of Advanced Science and Technology, Ryukoku University, Seta, Otsu, Shiga, 520-2194, Japan
| |
Collapse
|
3
|
Abrams R, Jesani MH, Browning A, Clayden J. Triarylmethanes and their Medium-Ring Analogues by Unactivated Truce-Smiles Rearrangement of Benzanilides. Angew Chem Int Ed Engl 2021; 60:11272-11277. [PMID: 33830592 PMCID: PMC8252078 DOI: 10.1002/anie.202102192] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Revised: 03/01/2021] [Indexed: 12/17/2022]
Abstract
Intramolecular nucleophilic aromatic substitution (Truce–Smiles rearrangement) of the anions of 2‐benzyl benzanilides leads to triarylmethanes in an operationally simple manner. The reaction succeeds even without electronic activation of the ring that plays the role of electrophile in the SNAr reaction, being accelerated instead by the preferred conformation imposed by the tertiary amide tether. The amide substituent of the product may be removed or transformed into alternative functional groups. A ring‐expanding variant (n to n+4) of the reaction provided a route to doubly benzo‐fused medium ring lactams of 10 or 11 members. Hammett analysis returned a ρ value consistent with the operation of a partially concerted reaction mechanism.
Collapse
Affiliation(s)
- Roman Abrams
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK
| | - Mehul H Jesani
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK
| | - Alex Browning
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK
| | - Jonathan Clayden
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK
| |
Collapse
|
4
|
Matsuoka R, Kimura S, Kusamoto T. Solid‐State Room‐Temperature Near‐Infrared Photoluminescence of a Stable Organic Radical. CHEMPHOTOCHEM 2021. [DOI: 10.1002/cptc.202100023] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Ryota Matsuoka
- Institute for Molecular Science 5-1 Higashiyama, Myodaiji Okazaki Aichi 444-8787 Japan
- SOKENDAI (The Graduate University for Advanced Studies) Shonan Village Hayama 240-0193 Kanagawa Japan
| | - Shojiro Kimura
- Institute for Materials Research Tohoku University 2-1-1 Katahira, Aoba-ku Sendai 980-8577 Japan
| | - Tetsuro Kusamoto
- Institute for Molecular Science 5-1 Higashiyama, Myodaiji Okazaki Aichi 444-8787 Japan
- SOKENDAI (The Graduate University for Advanced Studies) Shonan Village Hayama 240-0193 Kanagawa Japan
- JST-PRESTO 4-1-8, Honcho Kawaguchi Saitama 332-0012 Japan
| |
Collapse
|
5
|
Abrams R, Jesani MH, Browning A, Clayden J. Triarylmethanes and their Medium‐Ring Analogues by Unactivated Truce–Smiles Rearrangement of Benzanilides. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202102192] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Roman Abrams
- School of Chemistry University of Bristol, Cantock's Close Bristol BS8 1TS UK
| | - Mehul H. Jesani
- School of Chemistry University of Bristol, Cantock's Close Bristol BS8 1TS UK
| | - Alex Browning
- School of Chemistry University of Bristol, Cantock's Close Bristol BS8 1TS UK
| | - Jonathan Clayden
- School of Chemistry University of Bristol, Cantock's Close Bristol BS8 1TS UK
| |
Collapse
|
6
|
Sukhikh TS, Khisamov RM, Konchenko SN. Unexpectedly Long Lifetime of the Excited State of Benzothiadiazole Derivative and Its Adducts with Lewis Acids. Molecules 2021; 26:molecules26072030. [PMID: 33918327 PMCID: PMC8038179 DOI: 10.3390/molecules26072030] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 03/26/2021] [Accepted: 03/30/2021] [Indexed: 11/29/2022] Open
Abstract
We report a study of photoluminescent properties of 4-bromo-7-(3-pyridylamino)-2,1,3-benzothiadiazole (Py-btd) and its novel Lewis adducts: (PyH-btd)2(ZnCl4) and [Cu2Cl2(Py-btd)2{PPO}2]·2C7H8 (PPO = tetraphenyldiphosphine monoxide), whose crystal structure was determined by X-ray diffraction analysis. Py-btd exhibits a lifetime of 9 microseconds indicating its phosphorescent nature, which is rare for purely organic compounds. This phenomenon arises from the heavy atom effect: the presence of a bromine atom in Py-btd promotes mixing of the singlet and triplet states to allow efficient singlet-to-triplet intersystem crossing. The Lewis adducts also feature a microsecond lifetime while emitting in a higher energy range than free Py-btd, which opens up the possibility to color-tune luminescence of benzothiadiazole derivatives.
Collapse
|