1
|
Yu Q, Li X, Shen C, Yu Z, Guan J, Zheng J. Blue-Shifted and Broadened Fluorescence Enhancement by Visible and Mode-Selective Infrared Double Excitations. J Phys Chem A 2024; 128:2912-2922. [PMID: 38572812 DOI: 10.1021/acs.jpca.3c07060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/05/2024]
Abstract
Mode-selective vibrational excitations to modify the electronic states of fluorescein dianion in methanol solutions are carried out with a femtosecond visible pulse synchronized with a tunable high-power, narrow-band picosecond infrared (IR) pulse. In this work, simultaneous intensity enhancement, peak blueshift, and line width broadening of fluorescence are observed in the visible/IR double resonance experiments. Comprehensive investigations on the modulation mechanism with scanning the vibrational excitation frequencies, tuning the time delay between the two excitation pulses, theoretical calculations, and nonlinear and linear spectroscopic measurements suggest that the fluorescence intensity enhancement is caused by the increase of the Franck-Condon factor induced by the vibrational excitations at the electronic ground state. Various enhancement effects are observed as vibrations initially excited by the IR photons relax to populate the vibrational modes of lower frequencies. The peak blueshift and line width broadening are caused by both increasing the Franck-Condon factors among different subensembles because of IR pre-excitation and the long-lived processes induced by the initial IR excitation. The results demonstrate that the fluorescence from the visible/IR double resonance experiments is not a simple sum frequency effect, and vibrational relaxations can produce profound effects modifying luminescence.
Collapse
Affiliation(s)
- Qirui Yu
- College of Chemistry and Molecular Engineering, Beijing National Laboratory for Molecular Sciences, Peking University, Beijing 100871, China
| | - Xinmao Li
- College of Chemistry and Molecular Engineering, Beijing National Laboratory for Molecular Sciences, Peking University, Beijing 100871, China
| | - Chengzhen Shen
- College of Chemistry and Molecular Engineering, Beijing National Laboratory for Molecular Sciences, Peking University, Beijing 100871, China
| | - Zhihao Yu
- College of Chemistry and Molecular Engineering, Beijing National Laboratory for Molecular Sciences, Peking University, Beijing 100871, China
| | - Jianxin Guan
- College of Chemistry and Molecular Engineering, Beijing National Laboratory for Molecular Sciences, Peking University, Beijing 100871, China
| | - Junrong Zheng
- College of Chemistry and Molecular Engineering, Beijing National Laboratory for Molecular Sciences, Peking University, Beijing 100871, China
| |
Collapse
|
2
|
Liao Q, Li A, Huang A, Wang J, Chang K, Li H, Yao P, Zhong C, Xie P, Wang J, Li Z, Li Q. Controllable π-π coupling of intramolecular dimer models in aggregated states. Chem Sci 2024; 15:4364-4373. [PMID: 38516094 PMCID: PMC10952094 DOI: 10.1039/d3sc05533g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Accepted: 01/17/2024] [Indexed: 03/23/2024] Open
Abstract
π-π coupling as a common interaction plays a key role in emissions, transport and mechanical properties of organic materials. However, the precise control of π-π coupling is still challenging owing to the possible interference from other intermolecular interactions in the aggregated state, usually resulting in uncontrollable emission properties. Herein, with the rational construction of intramolecular dimer models and crystal engineering, π-π coupling can be subtly modulated by conformation variation with balanced π-π and π-solvent interactions and visualized by green-to-blue emission switching. Moreover, it can rapidly respond to temperature, pressure and mechanical force, affording a facile way to modulate π-π coupling in situ. This work contributes to a deeper understanding of the internal mechanism of molecular motions in aggregated states.
Collapse
Affiliation(s)
- Qiuyan Liao
- Hubei Key Lab on Organic and Polymeric Opto-Electronic Materials, Department of Chemistry, TaiKang Center for Life and Medical Sciences, Wuhan University Wuhan 430072 China
| | - Aisen Li
- Joint School of National University of Singapore and Tianjin University, International Campus of Tianjin University Fuzhou 350207 China
| | - Arui Huang
- Hubei Key Lab on Organic and Polymeric Opto-Electronic Materials, Department of Chemistry, TaiKang Center for Life and Medical Sciences, Wuhan University Wuhan 430072 China
| | - Jiaqiang Wang
- Institute of Molecular Aggregation Science, Tianjin University Tianjin 300072 China
| | - Kai Chang
- Hubei Key Lab on Organic and Polymeric Opto-Electronic Materials, Department of Chemistry, TaiKang Center for Life and Medical Sciences, Wuhan University Wuhan 430072 China
| | - Hehua Li
- Hubei Key Lab on Organic and Polymeric Opto-Electronic Materials, Department of Chemistry, TaiKang Center for Life and Medical Sciences, Wuhan University Wuhan 430072 China
| | - Pengfei Yao
- Hubei Key Lab on Organic and Polymeric Opto-Electronic Materials, Department of Chemistry, TaiKang Center for Life and Medical Sciences, Wuhan University Wuhan 430072 China
| | - Cheng Zhong
- Hubei Key Lab on Organic and Polymeric Opto-Electronic Materials, Department of Chemistry, TaiKang Center for Life and Medical Sciences, Wuhan University Wuhan 430072 China
| | - Peidong Xie
- Hubei Key Lab on Organic and Polymeric Opto-Electronic Materials, Department of Chemistry, TaiKang Center for Life and Medical Sciences, Wuhan University Wuhan 430072 China
| | - Jinfeng Wang
- Institute of Molecular Aggregation Science, Tianjin University Tianjin 300072 China
| | - Zhen Li
- Hubei Key Lab on Organic and Polymeric Opto-Electronic Materials, Department of Chemistry, TaiKang Center for Life and Medical Sciences, Wuhan University Wuhan 430072 China
- Institute of Molecular Aggregation Science, Tianjin University Tianjin 300072 China
| | - Qianqian Li
- Hubei Key Lab on Organic and Polymeric Opto-Electronic Materials, Department of Chemistry, TaiKang Center for Life and Medical Sciences, Wuhan University Wuhan 430072 China
| |
Collapse
|
3
|
Yin X, Zhai C, Hu S, Yue L, Xu T, Yao Z, Li Q, Liu R, Yao M, Sundqvist B, Liu B. Doping of charge-transfer molecules in cocrystals for the design of materials with novel piezo-activated luminescence. Chem Sci 2023; 14:1479-1484. [PMID: 36794196 PMCID: PMC9906791 DOI: 10.1039/d2sc06315h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Accepted: 01/11/2023] [Indexed: 01/12/2023] Open
Abstract
A novel piezo-activated luminescent material with wide range modulation of the luminescence wavelength and a giant intensity enhancement upon compression was prepared using a strategy of molecular doping. The doping of THT molecules into TCNB-perylene cocrystals results in the formation of a weak but pressure-enhanced emission center in the material at ambient pressure. Upon compression, the emissive band from the undoped component TCNB-perylene undergoes a normal red shift and emission quenching, while the weak emission center shows an anomalous blue shift from 615 nm to 574 nm and a giant luminescence enhancement up to 16 GPa. Further theoretical calculations show that doping by THT could modify intermolecular interactions, promote molecular deformation, and importantly, inject electrons into the host TCNB-perylene upon compression, which contributes to the novel piezochromic luminescence behavior. Based on this finding, we further propose a universal approach to design and regulate the piezo-activated luminescence of materials by using other similar dopants.
Collapse
Affiliation(s)
- Xiu Yin
- State Key Laboratory of Superhard Materials, College of Physics, Jilin University China
| | - Chunguang Zhai
- State Key Laboratory of Superhard Materials, College of Physics, Jilin University China
| | - Shuhe Hu
- State Key Laboratory of Superhard Materials, College of Physics, Jilin University China
| | - Lei Yue
- State Key Laboratory of Superhard Materials, College of Physics, Jilin University China
| | - Tongge Xu
- State Key Laboratory of Superhard Materials, College of Physics, Jilin University China
| | - Zhen Yao
- State Key Laboratory of Superhard Materials, College of Physics, Jilin University China
| | - Quanjun Li
- State Key Laboratory of Superhard Materials, College of Physics, Jilin University China
| | - Ran Liu
- State Key Laboratory of Superhard Materials, College of Physics, Jilin University China
| | - Mingguang Yao
- State Key Laboratory of Superhard Materials, College of Physics, Jilin University China
| | | | - Bingbing Liu
- State Key Laboratory of Superhard Materials, College of Physics, Jilin University China
| |
Collapse
|
4
|
Feng S, Zhao Y, Liang W. Substituent Effect on Vibrationally Resolved Absorption Spectra and Exciton Dynamics of Dipyrrolonaphthyridinedione Aggregates. J Phys Chem A 2022; 126:6395-6406. [PMID: 36073236 DOI: 10.1021/acs.jpca.2c03907] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Dipyrrolonaphthyridinedione (DPND) thin films exhibit interesting photophysical properties and singlet fission (SF) processes. A recent experimental work found that the alkyl substitution in the DPND skeleton has the remarkable influence on the characteristics of electronic absorption spectra and SF rates. Here, we theoretically elucidate the microscopic mechanism of the substituent effect on the optical properties and exciton dynamics of materials by combining the electronic structure calculations and the quantum dynamics simulations. The results show that the alkyl substituent has a minor effect on the single molecular properties but dramatically changes those of DPND aggregates via varying the intermolecular interactions. The aggregates of DPND with and without alkyl side chains exhibit the more likely characters of H-type aggregations. In the former (DPND6), the weak degree of mixing of intramolecular localized excited (LE) states and intermolecular charge transfer (CT) states makes the low-energy absorption band possess the predominant optical absorption, while in the latter (DPND), the CT and LE states are close in energy, together with their strong interaction, resulting in the substantial state-mixing, so that its two low-energy absorption bands have nearly equal oscillator strengths and a wide energy spacing of more than 0.5 eV. The simulation of exciton dynamics elucidates that the photoinitiated states in both aggregates cannot generate the free charge carrier because of the lack of enough driving forces. However, the population exchanges between LE and CT states in DPND aggregates are much faster than in DPND6 aggregates, indicating the different SF behaviors, consistent with the experimental observation.
Collapse
Affiliation(s)
- Shishi Feng
- State Key Laboratory of Physical Chemistry of Solid Surfaces, iChEM, Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, and College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, People's Republic of China
| | - Yi Zhao
- State Key Laboratory of Physical Chemistry of Solid Surfaces, iChEM, Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, and College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, People's Republic of China
| | - WanZhen Liang
- State Key Laboratory of Physical Chemistry of Solid Surfaces, iChEM, Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, and College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, People's Republic of China
| |
Collapse
|