1
|
Ji S, Peng D, Sun F, You Q, Wang R, Yan N, Zhou Y, Wang W, Tang Q, Xia N, Zeng Z, Wu Z. Coexistent, Competing Tunnelling, and Hopping Charge Transport in Compressed Metal Nanocluster Crystals. J Am Chem Soc 2023; 145:24012-24020. [PMID: 37903430 DOI: 10.1021/jacs.3c07007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2023]
Abstract
Understanding charge transport among metal particles with sizes of approximately 1 nm poses a great challenge due to the ultrasmall nanosize, yet it holds great significance in the development of innovative materials as substitutes for traditional semiconductors, which are insulative and unstable in less than ∼10 nm thickness. Herein, atomically precise gold nanoclusters with well-defined compositions and structures were investigated to establish a mathematical relation between conductivity and interparticle distance. This was accomplished using high-pressure in situ resistance characterizations, synchrotron X-ray diffraction (XRD), and the Murnaghan equation of state. Based on this precise correlation, it was predicted that the conductivity of Au25(SNap)18 (SNap: 1-naphthalenethiolate) solid is comparable to that of bulk silver when the interparticle distance is reduced to approximately 3.6 Å. Furthermore, the study revealed the coexisting, competing tunneling, and incoherent hopping charge transport mechanisms, which differed from those previously reported. The introduction of conjugation-structured ligands, tuning of the structures of metal nanoclusters, and use of high-pressure techniques contributed to enhanced conductivity, and thus, the charge carrier types were determined using Hall measurements. Overall, this study provides valuable insight into the charge transport in gold nanocluster solids and represents an important advancement in metal nanocluster semiconductor research.
Collapse
Affiliation(s)
- Shiyu Ji
- Key Laboratory of Materials Physics, Anhui Key Laboratory of Nanomaterials and Nanotechnology, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, Hefei 230031, P. R. China
- University of Science and Technology of China, Hefei 230601, P. R. China
| | - Di Peng
- Key Laboratory of Materials Physics, Anhui Key Laboratory of Nanomaterials and Nanotechnology, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, Hefei 230031, P. R. China
- University of Science and Technology of China, Hefei 230601, P. R. China
| | - Fang Sun
- School of Chemistry and Chemical Engineering, Chongqing Key Laboratory of Theoretical and Computational Chemistry, Chongqing University, Chongqing 401331, China
| | - Qing You
- Key Laboratory of Materials Physics, Anhui Key Laboratory of Nanomaterials and Nanotechnology, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, Hefei 230031, P. R. China
- Institute of Physical Science and Information Technology, Anhui University, Hefei 230601, P. R. China
| | - Runguo Wang
- Key Laboratory of Materials Physics, Anhui Key Laboratory of Nanomaterials and Nanotechnology, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, Hefei 230031, P. R. China
- University of Science and Technology of China, Hefei 230601, P. R. China
| | - Nan Yan
- Key Laboratory of Materials Physics, Anhui Key Laboratory of Nanomaterials and Nanotechnology, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, Hefei 230031, P. R. China
- Institute of Physical Science and Information Technology, Anhui University, Hefei 230601, P. R. China
| | - Yue Zhou
- Key Laboratory of Materials Physics, Anhui Key Laboratory of Nanomaterials and Nanotechnology, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, Hefei 230031, P. R. China
- University of Science and Technology of China, Hefei 230601, P. R. China
| | - Weiyi Wang
- University of Science and Technology of China, Hefei 230601, P. R. China
| | - Qing Tang
- School of Chemistry and Chemical Engineering, Chongqing Key Laboratory of Theoretical and Computational Chemistry, Chongqing University, Chongqing 401331, China
| | - Nan Xia
- Key Laboratory of Materials Physics, Anhui Key Laboratory of Nanomaterials and Nanotechnology, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, Hefei 230031, P. R. China
- Institute of Physical Science and Information Technology, Anhui University, Hefei 230601, P. R. China
| | - Zhi Zeng
- Key Laboratory of Materials Physics, Anhui Key Laboratory of Nanomaterials and Nanotechnology, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, Hefei 230031, P. R. China
| | - Zhikun Wu
- Key Laboratory of Materials Physics, Anhui Key Laboratory of Nanomaterials and Nanotechnology, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, Hefei 230031, P. R. China
- Institute of Physical Science and Information Technology, Anhui University, Hefei 230601, P. R. China
| |
Collapse
|
2
|
Kokkin DL, Reilly NJ, Ivanov M, Rathore R, Reid SA. Excitonic Coupling in Fluorene-Based Bichromophoric Systems: Vibrational Quenching and the Transition from Weak to Intermediate Coupling. J Phys Chem A 2023; 127:7198-7204. [PMID: 37594308 DOI: 10.1021/acs.jpca.3c03511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/19/2023]
Abstract
Excimeric systems (i.e., excited dimers) have well served as model compounds for the study of the delocalization of electronic energy over weakly interacting chromophores. However, there remain relatively few isolated systems in which such interactions can be studied experimentally at a level to afford detailed comparisons with theory. In this Article, we examine a series of covalently and noncovalently linked dimers of fluorene, as a model aromatic chromophore, where the formation of excimers requires a π-stacked, cofacial orientation at van der Waals contact. Building upon a series of seminal prior studies that examined vibronic quenching of the excitation interaction in van der Waals dimers, the key question that we sought to address here is whether a single quenching factor could reproduce experimental excitonic splittings across a series of covalently and noncovalently linked bichromophoric systems built from the same chromophore. In comparing experimentally measured excitonic splittings with calculated static splittings using time-dependent density functional methods, we find that all systems save one fall on a line with a slope of 0.080(8), reflecting a vibrational quenching of roughly 1 order of magnitude. The outlier, which shows a significantly reduced quenching factor, represents a cyclophane-linked system where the fluorene moieties are constrained in a cofacial arrangement. We argue that this system evidences the transition from the weak to intermediate coupling regime.
Collapse
Affiliation(s)
- Damian L Kokkin
- Department of Chemistry, Marquette University, Milwaukee, Wisconsin 53233, United States
| | - Neil J Reilly
- Department of Chemistry, University of Massachusetts-Boston, Boston, Massachusetts 02125, United States
| | - Maxim Ivanov
- Amgen Inc., 1 Amgen Center Drive, Thousand Oaks, California 91320, United States
| | | | - Scott A Reid
- Department of Chemistry, Marquette University, Milwaukee, Wisconsin 53233, United States
| |
Collapse
|
3
|
Rathore R, Abdelwahed SH. Design and Synthesis of Cofacially-Arrayed Polyfluorene Wires for Electron and Energy Transfer Studies. Molecules 2023; 28:molecules28093717. [PMID: 37175127 PMCID: PMC10180040 DOI: 10.3390/molecules28093717] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 04/17/2023] [Accepted: 04/18/2023] [Indexed: 05/15/2023] Open
Abstract
A study of cofacially arrayed π-systems is of particular importance for the design of functional materials for efficient long-range intra-chain charge transfer through the bulk semiconducting materials in the layers of photovoltaic devices. The effect of π-stacking between a pair of aromatic rings has been mainly studied in the form of cyclophanes, where aromatic rings are forced into a sandwich-like geometry, which extensively deforms the aromatic rings from planarity. The synthetic difficulties associated with the preparation of cyclophane-like structures has prevented the synthesis of many examples of their multi-layered analogues. Moreover, the few available multi-layered cyclophanes are not readily amenable to the structural modification required for the construction of D-spacer-A triads needed to explore mechanisms of electron and energy transfer. In this review, we recount how a detailed experimental and computational analysis of 1,3-diarylalkanes led to the design of a new class of cofacially arrayed polyfluorenes that retain their π-stacked structure. Thus, efficient synthetic strategies have been established for the ready preparation of monodisperse polyfluorenes with up to six π-stacked fluorenes, which afford ready access to D-spacer-A triads by linking donor and acceptor groups to the polyfluorene spacers via single methylenes. Detailed 1H NMR spectroscopy, X-ray crystallography, electrochemistry, and He(I) photoelectron spectroscopy of F2-F6 have confirmed the rigid cofacial stacking of multiple fluorenes in F2-F6, despite the presence of rotatable C-C bonds. These polyfluorenes (F2-F6) form stable cation radicals in which a single hole is delocalized amongst the stacked fluorenes, as judged by the presence of intense charge-resonance transition in their optical spectra. Interestingly, these studies also discern that delocalization of a single cationic charge could occur over multiple fluorene rings in F2-F6, while the exciton is likely localized only onto two fluorenes in F2-F6. Facile synthesis of the D-spacer-A triads allowed us to demonstrate that efficient triplet energy transfer can occur through π-stacked polyfluorenes; the mechanism of energy transfer crosses over from tunneling to hopping with increasing number of fluorenes in the polyfluorene spacer. We suggest that the development of rigidly held π-stacked polyfluorenes, described herein, with well-defined redox and optoelectronic properties provides an ideal scaffold for the study of electron and energy transfer in D-spacer-A triads, where the Fn spacers serve as models for cofacially stacked π-systems.
Collapse
Affiliation(s)
- Rajendra Rathore
- Department of Chemistry, Marquette University, Milwaukee, WI 53233, USA
| | - Sameh H Abdelwahed
- Department of Chemistry, Prairie View A&M University, Prairie View, TX 77446, USA
| |
Collapse
|
4
|
Mavrommati S, Skourtis SS. Molecular Wires for Efficient Long-Distance Triplet Energy Transfer. J Phys Chem Lett 2022; 13:9679-9687. [PMID: 36215956 PMCID: PMC9589895 DOI: 10.1021/acs.jpclett.2c02616] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Accepted: 10/03/2022] [Indexed: 06/16/2023]
Abstract
We propose design rules for building organic molecular bridges that enable coherent long-distance triplet-exciton transfer. Using these rules, we describe example polychromophoric structures with low inner-sphere exciton reorganization energies, low static and dynamic disorder, and enhanced π-stacking interactions between nearest-neighbor chromophores. These features lead to triplet-exciton eigenstates that are delocalized over several units at room temperature. The use of such bridges in donor-bridge-acceptor assemblies enables fast triplet-exciton transport over very long distances that is rate-limited by the donor-bridge injection and bridge-acceptor trapping rates.
Collapse
|
5
|
Zhang X, Wang P, Nie Y, Ma Q. Recent development of organic nanoemitter-based ECL sensing application. Trends Analyt Chem 2021. [DOI: 10.1016/j.trac.2021.116410] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
|
6
|
He S, Han Y, Guo J, Wu K. Entropy-Gated Thermally Activated Delayed Emission Lifetime in Phenanthrene-Functionalized CsPbBr 3 Perovskite Nanocrystals. J Phys Chem Lett 2021; 12:8598-8604. [PMID: 34468154 DOI: 10.1021/acs.jpclett.1c02547] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Charge and electronic energy transfer form the basis of many natural and artificial energy transduction systems. The energy landscapes that drive these transfer processes are often constructed from enthalpy changes. In contrast, the entropic effect, although occasionally invoked to explain some excited-state dynamics, has rarely been used to actively control charge/energy flow. Here we derive a generic formula describing how entropy can quantitatively gate the thermally activated delayed emission lifetime in semiconductor nanocrystal-molecular triplet acceptor complexes and experimentally verify the model using highly emissive, quantum-confined CsPbBr3 nanocrystals surface-functionalized with multiple phenanthrene triplet acceptors. Triplet energy transfer from photoexcited CsPbBr3 nanocrystals to phenanthrene is followed by thermally activated repopulation of nanocrystal excitons, leading to delayed nanocrystal emission. The lifetime of delayed emission increases with the phenanthrene/nanocrystal ratio, due to lowering of the free energy of the acceptor state by entropic gain. This study points toward a direction of using entropy to artificially design donor-acceptor light-emitting materials with predetermined excited-state lifetimes.
Collapse
Affiliation(s)
- Shan He
- State Key Laboratory of Molecular Reaction Dynamics and Dynamics Research Center for Energy and Environmental Materials, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, China
| | - Yaoyao Han
- State Key Laboratory of Molecular Reaction Dynamics and Dynamics Research Center for Energy and Environmental Materials, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jingwei Guo
- Key Laboratory of Chemical Lasers, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, China
| | - Kaifeng Wu
- State Key Laboratory of Molecular Reaction Dynamics and Dynamics Research Center for Energy and Environmental Materials, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| |
Collapse
|
7
|
Im EJ, Jung HW, Kang YK. Evaluation of
Through‐Space
Electronic Coupling in the Cofacially Aligned
π‐Stacked
Organic
Mixed‐Valence
System. B KOREAN CHEM SOC 2021. [DOI: 10.1002/bkcs.12242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Eun Ji Im
- Department of Chemistry Sangmyung University Seoul 03016 South Korea
| | - Hae Won Jung
- Department of Chemistry Sangmyung University Seoul 03016 South Korea
| | - Youn K. Kang
- Department of Chemistry Sangmyung University Seoul 03016 South Korea
| |
Collapse
|
8
|
Lai R, Liu Y, Luo X, Chen L, Han Y, Lv M, Liang G, Chen J, Zhang C, Di D, Scholes GD, Castellano FN, Wu K. Shallow distance-dependent triplet energy migration mediated by endothermic charge-transfer. Nat Commun 2021; 12:1532. [PMID: 33750766 PMCID: PMC7943758 DOI: 10.1038/s41467-021-21561-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Accepted: 02/03/2021] [Indexed: 12/14/2022] Open
Abstract
Conventional wisdom posits that spin-triplet energy transfer (TET) is only operative over short distances because Dexter-type electronic coupling for TET rapidly decreases with increasing donor acceptor separation. While coherent mechanisms such as super-exchange can enhance the magnitude of electronic coupling, they are equally attenuated with distance. Here, we report endothermic charge-transfer-mediated TET as an alternative mechanism featuring shallow distance-dependence and experimentally demonstrated it using a linked nanocrystal-polyacene donor acceptor pair. Donor-acceptor electronic coupling is quantitatively controlled through wavefunction leakage out of the core/shell semiconductor nanocrystals, while the charge/energy transfer driving force is conserved. Attenuation of the TET rate as a function of shell thickness clearly follows the trend of hole probability density on nanocrystal surfaces rather than the product of electron and hole densities, consistent with endothermic hole-transfer-mediated TET. The shallow distance-dependence afforded by this mechanism enables efficient TET across distances well beyond the nominal range of Dexter or super-exchange paradigms.
Collapse
Affiliation(s)
- Runchen Lai
- State Key Laboratory of Molecular Reaction Dynamics and Dynamics Research Center for Energy and Environmental Materials, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning, China
- State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, International Research Center for Advanced Photonics, Zhejiang University, Hangzhou, Zhejiang, China
| | - Yangyi Liu
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai, China
| | - Xiao Luo
- State Key Laboratory of Molecular Reaction Dynamics and Dynamics Research Center for Energy and Environmental Materials, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning, China
| | - Lan Chen
- National Laboratory of Solid State Microstructures, School of Physics and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, Jiangsu, China
| | - Yaoyao Han
- State Key Laboratory of Molecular Reaction Dynamics and Dynamics Research Center for Energy and Environmental Materials, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning, China
- University of the Chinese Academy of Sciences, Beijing, China
| | - Meng Lv
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai, China
| | - Guijie Liang
- Hubei Key Laboratory of Low Dimensional Optoelectronic Materials and Devices, Hubei University of Art and Science, Xiangyang, Hubei, China
| | - Jinquan Chen
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai, China
| | - Chunfeng Zhang
- National Laboratory of Solid State Microstructures, School of Physics and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, Jiangsu, China
| | - Dawei Di
- State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, International Research Center for Advanced Photonics, Zhejiang University, Hangzhou, Zhejiang, China
| | - Gregory D Scholes
- Frick Chemistry Laboratory, Princeton University, Princeton, NJ, USA
| | - Felix N Castellano
- Department of Chemistry, North Carolina State University, Raleigh, NC, USA
| | - Kaifeng Wu
- State Key Laboratory of Molecular Reaction Dynamics and Dynamics Research Center for Energy and Environmental Materials, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning, China.
| |
Collapse
|
9
|
Osella S. Artificial Photosynthesis: Is Computation Ready for the Challenge Ahead? NANOMATERIALS 2021; 11:nano11020299. [PMID: 33498961 PMCID: PMC7911014 DOI: 10.3390/nano11020299] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Revised: 01/19/2021] [Accepted: 01/20/2021] [Indexed: 12/13/2022]
Abstract
A tremendous effort is currently devoted to the generation of novel hybrid materials with enhanced electronic properties for the creation of artificial photosynthetic systems. This compelling and challenging problem is well-defined from an experimental point of view, as the design of such materials relies on combining organic materials or metals with biological systems like light harvesting and redox-active proteins. Such hybrid systems can be used, e.g., as bio-sensors, bio-fuel cells, biohybrid photoelectrochemical cells, and nanostructured photoelectronic devices. Despite these efforts, the main bottleneck is the formation of efficient interfaces between the biological and the organic/metal counterparts for efficient electron transfer (ET). It is within this aspect that computation can make the difference and improve the current understanding of the mechanisms underneath the interface formation and the charge transfer efficiency. Yet, the systems considered (i.e., light harvesting protein, self-assembly monolayer and surface assembly) are more and more complex, reaching (and often passing) the limit of current computation power. In this review, recent developments in computational methods for studying complex interfaces for artificial photosynthesis will be provided and selected cases discussed, to assess the inherent ability of computation to leave a mark in this field of research.
Collapse
Affiliation(s)
- Silvio Osella
- Chemical and Biological Systems Simulation Lab, Center of New Technologies, University of Warsaw, Banacha 2C, 02-097 Warsaw, Poland
| |
Collapse
|
10
|
Davidson S, Fruchtman A, Pollock FA, Gauger EM. The dark side of energy transport along excitonic wires: On-site energy barriers facilitate efficient, vibrationally mediated transport through optically dark subspaces. J Chem Phys 2020; 153:134701. [PMID: 33032411 DOI: 10.1063/5.0023702] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We present a novel, counter-intuitive method, based on dark-state protection, for significantly improving exciton transport efficiency through "wires" comprising a chain of molecular sites with an intrinsic energy gradient. Specifically, by introducing "barriers" to the energy landscape at regular intervals along the transport path, we find that undesirable radiative recombination processes are suppressed due to a clear separation of sub-radiant and super-radiant eigenstates in the system. This, in turn, can lead to an improvement in transmitted power by many orders of magnitude, even for very long chains. From there, we analyze the robustness of this phenomenon to changes in both system and environment properties to show that this effect can be beneficial over a range of different thermal and optical environment regimes. Finally, we show that the novel energy landscape presented here may provide a useful foundation for overcoming the short length scales over which exciton diffusion typically occurs in organic photo-voltaics and other nanoscale transport scenarios, thus leading to considerable potential improvements in the efficiency of such devices.
Collapse
Affiliation(s)
- Scott Davidson
- SUPA, Institute of Photonics and Quantum Sciences, Heriot-Watt University, Edinburgh EH14 4AS, United Kingdom
| | - Amir Fruchtman
- Department of Materials, University of Oxford, Oxford OX1 3PH, United Kingdom
| | - Felix A Pollock
- School of Physics and Astronomy, Monash University, Clayton, Victoria 3800, Australia
| | - Erik M Gauger
- SUPA, Institute of Photonics and Quantum Sciences, Heriot-Watt University, Edinburgh EH14 4AS, United Kingdom
| |
Collapse
|
11
|
Huang Z, Xu Z, Huang T, Gray V, Moth-Poulsen K, Lian T, Tang ML. Evolution from Tunneling to Hopping Mediated Triplet Energy Transfer from Quantum Dots to Molecules. J Am Chem Soc 2020; 142:17581-17588. [DOI: 10.1021/jacs.0c07727] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Zhiyuan Huang
- Department of Chemistry, University of California, Riverside, Riverside, California 92521, United States
| | - Zihao Xu
- Department of Chemistry, Emory University, Atlanta, Georgia 30322, United States
| | - Tingting Huang
- Department of Chemistry, University of California, Riverside, Riverside, California 92521, United States
| | - Victor Gray
- Department of Chemistry and Chemical Engineering, Chalmers University of Technology, 412 96 Gothenburg, Sweden
- Department of Chemistry − Ångström Laboratory, Uppsala University, Box
523, 751 20 Uppsala, Sweden
| | - Kasper Moth-Poulsen
- Department of Chemistry and Chemical Engineering, Chalmers University of Technology, 412 96 Gothenburg, Sweden
| | - Tianquan Lian
- Department of Chemistry, Emory University, Atlanta, Georgia 30322, United States
| | - Ming Lee Tang
- Department of Chemistry, University of California, Riverside, Riverside, California 92521, United States
| |
Collapse
|
12
|
Roy S, Xie O, Dorval Courchesne N. Challenges in engineering conductive protein fibres: Disentangling the knowledge. CAN J CHEM ENG 2020. [DOI: 10.1002/cjce.23836] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Sophia Roy
- Department of Chemical Engineering McGill University Montréal Québec Canada
| | - Oliver Xie
- Department of Chemical Engineering McGill University Montréal Québec Canada
| | | |
Collapse
|
13
|
Ji SY, Zhao W, Gao H, Pan JB, Xu CH, Quan YW, Xu JJ, Chen HY. Highly Efficient Aggregation-Induced Electrochemiluminescence of Polyfluorene Derivative Nanoparticles Containing Tetraphenylethylene. iScience 2020; 23:100774. [PMID: 31887665 PMCID: PMC6941856 DOI: 10.1016/j.isci.2019.100774] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Revised: 11/12/2019] [Accepted: 12/09/2019] [Indexed: 11/21/2022] Open
Abstract
The aggregation-induced electrochemiluminescence (AIECL) of polyfluorene derivative nanoparticles containing tetraphenylethylene (TPE) in aqueous media is reported in this work. The TPE unit limits the intramolecular free rotation of phenyl rings, as well as the π-π stacking interactions of molecules, which significantly enhances ECL signal of the polyfluorene nanoparticles. With co-reactants of tri-n-propylamine (TPrA) and S2O82-, the copolymer nanoparticles show visualized ECL emissions at both positive and negative potentials. The ECL efficiency of copolymer nanoparticles in solid state is 163% compared with that of standard ECL species, Ru(bpy)32+. And at negative potential, the ECL intensity of copolymer nanoparticles is even stronger with 6.5 times compared with that at positive potential. The ECL generation mechanisms are analyzed detailed by annihilation and co-reactant route transient ECL test (millisecond scale). This work provides a reference for the organic structure design for AIECL and shows promising potential in luminescent device and biological applications.
Collapse
Affiliation(s)
- Si-Yuan Ji
- State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Wei Zhao
- State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Hang Gao
- Key Lab of Mesoscopic Chemistry of MOE and Jiangsu Key Laboratory of Advanced Organic Materials, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Jian-Bin Pan
- State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Cong-Hui Xu
- State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China.
| | - Yi-Wu Quan
- Key Laboratory of High Performance Polymer Materials & Technology of Ministry of Education, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China.
| | - Jing-Juan Xu
- State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China.
| | - Hong-Yuan Chen
- State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| |
Collapse
|
14
|
Jung HW, Yoon SE, Carroll PJ, Gau MR, Therien MJ, Kang YK. Distance Dependence of Electronic Coupling in Rigid, Cofacially Compressed, π-Stacked Organic Mixed-Valence Systems. J Phys Chem B 2020; 124:1033-1048. [DOI: 10.1021/acs.jpcb.9b09578] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Hae Won Jung
- Department of Chemistry, Sangmyung University, Seoul 03016, Korea
| | - Sung Ewn Yoon
- Department of Chemistry, Sangmyung University, Seoul 03016, Korea
| | - Patrick J. Carroll
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Michael R. Gau
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Michael J. Therien
- Department of Chemistry, Duke University, Durham, North Carolina 27708, United States
| | - Youn K. Kang
- Department of Chemistry, Sangmyung University, Seoul 03016, Korea
| |
Collapse
|
15
|
Wang B, Yu Y, Zhang H, Xuan Y, Chen G, Ma W, Li J, Yu J. Carbon Dots in a Matrix: Energy‐Transfer‐Enhanced Room‐Temperature Red Phosphorescence. Angew Chem Int Ed Engl 2019; 58:18443-18448. [DOI: 10.1002/anie.201911035] [Citation(s) in RCA: 71] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Revised: 09/26/2019] [Indexed: 11/07/2022]
Affiliation(s)
- Bolun Wang
- State Key Laboratory of Inorganic Synthesis and Preparative ChemistryCollege of ChemistryJilin University Changchun 130012 P. R. China
| | - Yue Yu
- State Key Laboratory of Inorganic Synthesis and Preparative ChemistryCollege of ChemistryJilin University Changchun 130012 P. R. China
| | - Hongyue Zhang
- State Key Laboratory of Inorganic Synthesis and Preparative ChemistryCollege of ChemistryJilin University Changchun 130012 P. R. China
| | - Yuzhi Xuan
- State Key Laboratory of Inorganic Synthesis and Preparative ChemistryCollege of ChemistryJilin University Changchun 130012 P. R. China
| | - Guangrui Chen
- State Key Laboratory of Inorganic Synthesis and Preparative ChemistryCollege of ChemistryJilin University Changchun 130012 P. R. China
| | - Wenyan Ma
- State Key Laboratory of Inorganic Synthesis and Preparative ChemistryCollege of ChemistryJilin University Changchun 130012 P. R. China
| | - Jiyang Li
- State Key Laboratory of Inorganic Synthesis and Preparative ChemistryCollege of ChemistryJilin University Changchun 130012 P. R. China
| | - Jihong Yu
- State Key Laboratory of Inorganic Synthesis and Preparative ChemistryCollege of ChemistryJilin University Changchun 130012 P. R. China
- International Center of Future ScienceJilin University 2699 Qianjin Street Changchun 130012 P. R. China
| |
Collapse
|
16
|
Carbon Dots in a Matrix: Energy‐Transfer‐Enhanced Room‐Temperature Red Phosphorescence. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201911035] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
17
|
Küçüköz B, Adinarayana B, Osuka A, Albinsson B. Electron transfer reactions in sub-porphyrin-naphthyldiimide dyads. Phys Chem Chem Phys 2019; 21:16477-16485. [PMID: 31321401 DOI: 10.1039/c9cp03725j] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
A series of donor-acceptor compounds based on a sub-porphyrin (SubP) as an electron donor and naphthyldiimide (NDI) as an acceptor has been designed, synthesized and investigated by time-resolved emission and transient absorption measurements. The donor and acceptor are separated by a single phenyl spacer substituted by methyl groups in order to systematically vary the electronic coupling. The electron transfer reactions in toluene are found to be quite fast; charge separation is quantitative and occurs within 5-10 ps and charge recombination occurs in 1-10 ns, depending on the substitution pattern. As expected, when steric bulk is introduced on the adjoining phenyl group, electron transfer rates slow down because of smaller electronic coupling. Quantum mechanical modelling of the potential energy for twisting the dihedral angles combined with a simplified model of the electronic coupling semi-quantitatively explains the observed variation of the electron transfer rates. Investigating the temperature variation of the charge separation in 2-methyltetrahydrofuran (2-MTHF) and analyzing using the Marcus model allow experimental estimation of the electronic coupling and reorganization energies. At low temperature, relatively strong phosphorescence is observed from the donor-acceptor compounds with onset at 660 nm signaling that charge recombination occurs, at least partially, through the sub-porphyrin localized triplet excited state. Finally, it is noted that charge separation in all SubP-NDI dyads is efficient even at cryogenic temperatures (85 K) in 2-MTHF glass.
Collapse
Affiliation(s)
- Betül Küçüköz
- Chemistry and Chemical Engineering, Chalmers University of Technology, Gothenburg, Sweden.
| | - B Adinarayana
- Department of Chemistry, Kyoto University, Kyoto, Japan
| | | | - Bo Albinsson
- Chemistry and Chemical Engineering, Chalmers University of Technology, Gothenburg, Sweden.
| |
Collapse
|
18
|
Nazarov VB, Avakian VG, Alfimov MV. Benzophenone-Sensitized Long-Lived Phosphorescence of Naphthalene-d8 at Room Temperature in a Complex with Beta-Cyclodextrin and Cyclohexane. HIGH ENERGY CHEMISTRY 2019. [DOI: 10.1134/s0018143919020115] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
19
|
Charge-transfer or excimeric state? Exploring the nature of the excited state in cofacially arrayed polyfluorene derivatives. J Photochem Photobiol A Chem 2019. [DOI: 10.1016/j.jphotochem.2019.01.030] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
20
|
Kohler L, Mulfort KL. Photoinduced electron transfer kinetics of linked Ru-Co photocatalyst dyads. J Photochem Photobiol A Chem 2019. [DOI: 10.1016/j.jphotochem.2018.12.025] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
21
|
Peng Y, Lu B, Wu F, Zhang F, Lu JE, Kang X, Ping Y, Chen S. Point of Anchor: Impacts on Interfacial Charge Transfer of Metal Oxide Nanoparticles. J Am Chem Soc 2018; 140:15290-15299. [PMID: 30345757 DOI: 10.1021/jacs.8b08035] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Photoinduced charge transfer across the metal oxide-organic ligand interface plays a key role in the diverse applications of metal oxide nanomaterials/nanostructures, such as photovoltaics, photocatalysis, and optoelectronics. Thus far, most studies are focused on molecular engineering of the organic chromophores, where the charge-transfer properties have been found to dictate the photo absorption efficiency and eventual device performance. Yet, as the chromophores are mostly bound onto the metal oxide surfaces by hydroxyl or carboxyl anchors, the impacts of the bonding interactions at the metal oxide-ligand interface on interfacial charge transfer have remained largely unexplored. Herein, acetylene derivatives are demonstrated as effective surface capping ligands for metal oxide nanoparticles, as exemplified with TiO2, RuO2, and ZnO. Experimental studies and first-principles calculations suggest the formation of M-O-C≡C- core-ligand linkages that lead to effective interfacial charge delocalization, in contrast to hopping/tunneling by the conventional M-O-CO- interfacial bonds in the carboxyl-capped counterparts. This leads to the generation of an interfacial state within the oxide bandgap and much enhanced sensitization of the nanoparticle photoluminescence emissions as well as photocatalytic activity, as manifested in the comparative studies with TiO2 nanoparticles functionalized with ethynylpyrene and pyrenecarboxylic acid. These results highlight the significance of the unique interfacial bonding chemistry by acetylene anchoring group in facilitating efficient charge transfer through the oxide-ligand interfacial linkage and hence the fundamental implication in their practical applications.
Collapse
Affiliation(s)
- Yi Peng
- Department of Chemistry and Biochemistry , University of California , 1156 High Street , Santa Cruz , California 95060 , United States
| | - Bingzhang Lu
- Department of Chemistry and Biochemistry , University of California , 1156 High Street , Santa Cruz , California 95060 , United States
| | - Feng Wu
- Department of Chemistry and Biochemistry , University of California , 1156 High Street , Santa Cruz , California 95060 , United States
| | - Fengqi Zhang
- New Energy Research Institute, School of Environment and Energy , South China University of Technology, Guangzhou Higher Education Mega Center , Guangzhou , Guangdong 510006 , China
| | - Jia En Lu
- Department of Chemistry and Biochemistry , University of California , 1156 High Street , Santa Cruz , California 95060 , United States
| | - Xiongwu Kang
- New Energy Research Institute, School of Environment and Energy , South China University of Technology, Guangzhou Higher Education Mega Center , Guangzhou , Guangdong 510006 , China
| | - Yuan Ping
- Department of Chemistry and Biochemistry , University of California , 1156 High Street , Santa Cruz , California 95060 , United States
| | - Shaowei Chen
- Department of Chemistry and Biochemistry , University of California , 1156 High Street , Santa Cruz , California 95060 , United States.,New Energy Research Institute, School of Environment and Energy , South China University of Technology, Guangzhou Higher Education Mega Center , Guangzhou , Guangdong 510006 , China
| |
Collapse
|
22
|
Kokkin D, Ivanov M, Loman J, Cai JZ, Uhler B, Reilly N, Rathore R, Reid SA. π - π stacking vs. C-H/ π interaction: Excimer formation and charge resonance stabilization in van der Waals clusters of 9,9'-dimethylfluorene. J Chem Phys 2018; 149:134314. [PMID: 30292228 DOI: 10.1063/1.5044648] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Studies of exciton and hole stabilization in multichromophoric systems underpin our understanding of electron transfer and transport in materials and biomolecules. The simplest model systems are dimeric, and recently we compared the gas-phase spectroscopy and dynamics of van der Waals dimers of fluorene, 9-methylfluorene (MF), and 9,9'-dimethylfluorene (F1) to assess how sterically controlled facial encumbrance modulates the dynamics of excimer formation and charge resonance stabilization (CRS). Dimers of fluorene and MF show only excimer emission upon electronic excitation, and significant CRS as evidenced in a reduced ionization potential for the dimer relative the monomer. By contrast, the dimer of F1 shows no excimeric emission, rather structured emission from the locally excited state of a tilted (non π-stacked) dimer, evidencing the importance of C-H/π interactions and increased steric constraints that restrict a cofacial approach. In this work, we report our full results on van der Waals clusters of F1, using a combination of theory and experiments that include laser-induced fluorescence, mass-selected two-color resonant two-photon ionization spectroscopy, and two-color appearance potential measurements. We use the latter to derive the binding energies of the F1 dimer in ground, excited, and cation radical states. Our results are compared with van der Waals and covalently linked clusters of fluorene to assess both the relative strength of π-stacking and C-H/π interactions in polyaromatic assemblies and the role of π-stacking in excimer formation and CRS.
Collapse
Affiliation(s)
- Damian Kokkin
- Department of Chemistry, Marquette University, Milwaukee, Wisconsin 53233, USA
| | - Maxim Ivanov
- Department of Chemistry, Marquette University, Milwaukee, Wisconsin 53233, USA
| | - John Loman
- Department of Chemistry, Marquette University, Milwaukee, Wisconsin 53233, USA
| | - Jin-Zhe Cai
- Department of Chemistry, Marquette University, Milwaukee, Wisconsin 53233, USA
| | - Brandon Uhler
- Department of Chemistry, Marquette University, Milwaukee, Wisconsin 53233, USA
| | - Neil Reilly
- Department of Chemistry, Marquette University, Milwaukee, Wisconsin 53233, USA
| | - Rajendra Rathore
- Department of Chemistry, Marquette University, Milwaukee, Wisconsin 53233, USA
| | - Scott A Reid
- Department of Chemistry, Marquette University, Milwaukee, Wisconsin 53233, USA
| |
Collapse
|
23
|
Schmidt HC, Guo X, Richard PU, Neuburger M, Palivan CG, Wenger OS. Mixed-Valent Molecular Triple Deckers. Angew Chem Int Ed Engl 2018; 57:11688-11691. [PMID: 29985557 DOI: 10.1002/anie.201806549] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Indexed: 12/13/2022]
Abstract
Two phenothiazine (PTZ) moieties were connected via naphthalene spacers to a central arene to result in stacked PTZ-arene-PTZ structure elements. Benzene and tetramethoxybenzene units served as central arenes mediating electronic communication between the two PTZ units. Based on cyclic voltammetry, UV/Vis-NIR absorption, EPR spectroscopy, and computational studies, the one-electron oxidized forms of the resulting compounds behave as class II organic mixed-valence species in which the unpaired electron is partially delocalized over both PTZ units. The barrier for intramolecular electron transfer depends on the nature of the central arene sandwiched between the two PTZ moieties. These are the first examples of rigid organic mixed-valent triple-decker compounds with possible electron-transfer pathways directly across a stacked structure, and they illustrate the potential of oligo-naphthalene building blocks for long-range electron transfer and a future molecular electronics technology.
Collapse
Affiliation(s)
- Hauke C Schmidt
- Department of Chemistry, University of Basel, St. Johanns-Ring 19, 4056, Basel, Switzerland
| | - Xingwei Guo
- Department of Chemistry, University of Basel, St. Johanns-Ring 19, 4056, Basel, Switzerland
| | - Pascal U Richard
- Department of Chemistry, University of Basel, Mattenstrasse 24a, BPR 1096, 4002, Basel, Switzerland
| | - Markus Neuburger
- Department of Chemistry, University of Basel, Mattenstrasse 24a, BPR 1096, 4002, Basel, Switzerland
| | - Cornelia G Palivan
- Department of Chemistry, University of Basel, Mattenstrasse 24a, BPR 1096, 4002, Basel, Switzerland
| | - Oliver S Wenger
- Department of Chemistry, University of Basel, St. Johanns-Ring 19, 4056, Basel, Switzerland
| |
Collapse
|
24
|
Zhang S, Chen W, Dai G, Yang F, Chen L. Fused Carbazole-Based Dyads: Synthesis, Solvatochromism and Sensing Properties. ASIAN J ORG CHEM 2018. [DOI: 10.1002/ajoc.201800378] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- Simeng Zhang
- Tianjin Key Laboratory of Molecular Optoelectronic Science; Department of Chemistry; School of Science; Tianjin University; Tianjin 300072 China
| | - Weiben Chen
- Tianjin Key Laboratory of Molecular Optoelectronic Science; Department of Chemistry; School of Science; Tianjin University; Tianjin 300072 China
| | - Gaole Dai
- Institute of Functional Nano & Soft Materials (FUNSOM); Soochow University; Jiangsu 215123 China
| | - Fan Yang
- Tianjin Key Laboratory of Molecular Optoelectronic Science; Department of Chemistry; School of Science; Tianjin University; Tianjin 300072 China
| | - Long Chen
- Tianjin Key Laboratory of Molecular Optoelectronic Science; Department of Chemistry; School of Science; Tianjin University; Tianjin 300072 China
| |
Collapse
|
25
|
Schmidt HC, Guo X, Richard PU, Neuburger M, Palivan CG, Wenger OS. Mixed-Valent Molecular Triple Deckers. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201806549] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Hauke C. Schmidt
- Department of Chemistry; University of Basel; St. Johanns-Ring 19 4056 Basel Switzerland
| | - Xingwei Guo
- Department of Chemistry; University of Basel; St. Johanns-Ring 19 4056 Basel Switzerland
| | - Pascal U. Richard
- Department of Chemistry; University of Basel; Mattenstrasse 24a, BPR 1096 4002 Basel Switzerland
| | - Markus Neuburger
- Department of Chemistry; University of Basel; Mattenstrasse 24a, BPR 1096 4002 Basel Switzerland
| | - Cornelia G. Palivan
- Department of Chemistry; University of Basel; Mattenstrasse 24a, BPR 1096 4002 Basel Switzerland
| | - Oliver S. Wenger
- Department of Chemistry; University of Basel; St. Johanns-Ring 19 4056 Basel Switzerland
| |
Collapse
|
26
|
Wang D, Talipov MR, Ivanov MV, Mirzaei S, Lindeman SV, Cai S, Rathore R, Reid SA. Molecular Actuators in Action: Electron-Transfer-Induced Conformation Transformation in Cofacially Arrayed Polyfluorenes. J Phys Chem Lett 2018; 9:4233-4238. [PMID: 29985630 DOI: 10.1021/acs.jpclett.8b01918] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
There is much current interest in the design of molecular actuators, which undergo reversible, controlled motion in response to an external stimulus (light, heat, oxidation, etc.). Here we describe the design and synthesis of a series of cofacially arrayed polyfluorenes (MeF nH m) with varied end-capping groups, which undergo redox-controlled electromechanical actuation. Such cofacially arrayed polyfluorenes are a model molecular scaffold to investigate fundamental processes of charge and energy transfer across a π-stacked assembly, and we show with the aid of NMR and optical spectroscopies, X-ray crystallography and DFT calculations that in the neutral state the conformation of MeF nH1 and MeF nH2 is open rather than cofacial, with a conformational dependence that is highly influenced by the local environment. Upon (electro)chemical oxidation, these systems undergo a reversible transformation into a closed fully π-stacked conformation, driven by charge-resonance stabilization of the cationic charge. These findings are expected to aid the design of novel wire-like cofacially arrayed systems capable of undergo redox-controlled actuation.
Collapse
Affiliation(s)
- Denan Wang
- Department of Chemistry , Marquette University , Milwaukee , Wisconsin 53201 , United States
| | - Marat R Talipov
- Department of Chemistry , Marquette University , Milwaukee , Wisconsin 53201 , United States
| | - Maxim V Ivanov
- Department of Chemistry , Marquette University , Milwaukee , Wisconsin 53201 , United States
| | - Saber Mirzaei
- Department of Chemistry , Marquette University , Milwaukee , Wisconsin 53201 , United States
| | - Sergey V Lindeman
- Department of Chemistry , Marquette University , Milwaukee , Wisconsin 53201 , United States
| | - Sheng Cai
- Department of Chemistry , Marquette University , Milwaukee , Wisconsin 53201 , United States
| | - Rajendra Rathore
- Department of Chemistry , Marquette University , Milwaukee , Wisconsin 53201 , United States
| | - Scott A Reid
- Department of Chemistry , Marquette University , Milwaukee , Wisconsin 53201 , United States
| |
Collapse
|
27
|
Zhen S, Mao JC, Chen L, Ding S, Luo W, Zhou XS, Qin A, Zhao Z, Tang BZ. Remarkable Multichannel Conductance of Novel Single-Molecule Wires Built on Through-Space Conjugated Hexaphenylbenzene. NANO LETTERS 2018; 18:4200-4205. [PMID: 29911870 DOI: 10.1021/acs.nanolett.8b01082] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Through-bond conjugated molecules are the major frameworks for traditional molecular wires, while through-space conjugated units are rarely utilized and studied although they have shown unique conducting potential. Herein, we present novel single-molecule wires built on through-space conjugated hexaphenylbenzene. Their conductance, measured by the scanning tunneling microscopy based break-junction technique, increases with the improvement of through-space conjugation and finally reaches a remarkable value (12.28 nS) which greatly exceeds that of conventional through-bond conjugated counterpart (2.45 nS). The multichannel conducting model by integrating through-space and through-bond conjugations could be a promising strategy for the further design of robust single-molecule wires with advanced conductance and stability.
Collapse
Affiliation(s)
- Shijie Zhen
- Center for Aggregation-Induced Emission, State Key Laboratory of Luminescent Materials and Devices , South China University of Technology , Guangzhou 510640 , China
| | - Jin-Chuan Mao
- Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Institute of Physical Chemistry , Zhejiang Normal University , Jinhua , Zhejiang 321004 , China
| | - Long Chen
- Center for Aggregation-Induced Emission, State Key Laboratory of Luminescent Materials and Devices , South China University of Technology , Guangzhou 510640 , China
| | - Siyang Ding
- Center for Aggregation-Induced Emission, State Key Laboratory of Luminescent Materials and Devices , South China University of Technology , Guangzhou 510640 , China
| | - Wenwen Luo
- Center for Aggregation-Induced Emission, State Key Laboratory of Luminescent Materials and Devices , South China University of Technology , Guangzhou 510640 , China
| | - Xiao-Shun Zhou
- Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Institute of Physical Chemistry , Zhejiang Normal University , Jinhua , Zhejiang 321004 , China
| | - Anjun Qin
- Center for Aggregation-Induced Emission, State Key Laboratory of Luminescent Materials and Devices , South China University of Technology , Guangzhou 510640 , China
| | - Zujin Zhao
- Center for Aggregation-Induced Emission, State Key Laboratory of Luminescent Materials and Devices , South China University of Technology , Guangzhou 510640 , China
| | - Ben Zhong Tang
- Center for Aggregation-Induced Emission, State Key Laboratory of Luminescent Materials and Devices , South China University of Technology , Guangzhou 510640 , China
- Department of Chemistry, Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction , The Hong Kong University of Science & Technology , Clear Water Bay , Kowloon, Hong Kong , China
| |
Collapse
|
28
|
Wang D, Ivanov MV, Kokkin D, Loman J, Cai J, Reid SA, Rathore R. The Role of Torsional Dynamics on Hole and Exciton Stabilization in π‐Stacked Assemblies: Design of Rigid Torsionomers of a Cofacial Bifluorene. Angew Chem Int Ed Engl 2018; 57:8189-8193. [DOI: 10.1002/anie.201804337] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Indexed: 11/12/2022]
Affiliation(s)
- Denan Wang
- Department of Chemistry Marquette University Milwaukee WI 53201-1881 USA
| | - Maxim V. Ivanov
- Department of Chemistry Marquette University Milwaukee WI 53201-1881 USA
| | - Damian Kokkin
- Department of Chemistry Marquette University Milwaukee WI 53201-1881 USA
| | - John Loman
- Department of Chemistry Marquette University Milwaukee WI 53201-1881 USA
| | - Jin‐Zhe Cai
- Department of Chemistry Marquette University Milwaukee WI 53201-1881 USA
| | - Scott A. Reid
- Department of Chemistry Marquette University Milwaukee WI 53201-1881 USA
| | - Rajendra Rathore
- Department of Chemistry Marquette University Milwaukee WI 53201-1881 USA
| |
Collapse
|
29
|
Wang D, Ivanov MV, Kokkin D, Loman J, Cai J, Reid SA, Rathore R. The Role of Torsional Dynamics on Hole and Exciton Stabilization in π‐Stacked Assemblies: Design of Rigid Torsionomers of a Cofacial Bifluorene. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201804337] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Denan Wang
- Department of Chemistry Marquette University Milwaukee WI 53201-1881 USA
| | - Maxim V. Ivanov
- Department of Chemistry Marquette University Milwaukee WI 53201-1881 USA
| | - Damian Kokkin
- Department of Chemistry Marquette University Milwaukee WI 53201-1881 USA
| | - John Loman
- Department of Chemistry Marquette University Milwaukee WI 53201-1881 USA
| | - Jin‐Zhe Cai
- Department of Chemistry Marquette University Milwaukee WI 53201-1881 USA
| | - Scott A. Reid
- Department of Chemistry Marquette University Milwaukee WI 53201-1881 USA
| | - Rajendra Rathore
- Department of Chemistry Marquette University Milwaukee WI 53201-1881 USA
| |
Collapse
|
30
|
Schmidt HC, Larsen CB, Wenger OS. Electron Transfer around a Molecular Corner. Angew Chem Int Ed Engl 2018; 57:6696-6700. [DOI: 10.1002/anie.201800396] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Revised: 02/02/2018] [Indexed: 11/11/2022]
Affiliation(s)
- Hauke C. Schmidt
- Department of ChemistryUniversity of Basel St. Johanns-Ring 19 4056 Basel Switzerland
| | - Christopher B. Larsen
- Department of ChemistryUniversity of Basel St. Johanns-Ring 19 4056 Basel Switzerland
| | - Oliver S. Wenger
- Department of ChemistryUniversity of Basel St. Johanns-Ring 19 4056 Basel Switzerland
| |
Collapse
|
31
|
Hu J, Wyatt PB, Gillin WP, Ye H. Continuous Tuning of Organic Phosphorescence by Diluting Triplet Diffusion at the Molecular Level. J Phys Chem Lett 2018; 9:2022-2024. [PMID: 29617138 DOI: 10.1021/acs.jpclett.8b00673] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Organic long-persistent phosphorescent materials are advantageous due to the cost-effectiveness and easy processability. The organic phosphorescence is achieved by the long-lived triplet excitons, and the challenges are recognized regarding the various nonradiative pathways to quench the emission lifetime. Taming long-lived phosphorescence is generally engaged with the charge-transfer or exciton diffusion in molecular stacking to stabilize triplet excitons or form a photoinduced ionized state. Herein, we elucidate that the triplet-diffusion can cause a significant quenching that is not thermally activated by using a system of perfluorinated organic complexes. Hence, we suggest a coevaporation technique to dilute a single phosphorescence-emitting molecule with another optically inactive molecule to suppress the diffusion-induced quenching, tuning the phosphorescence lifetime and spectral features continuously. The work successfully suggests a general semitheoretical method of quantifying the population equilibrium to elucidate the loss mechanisms for organic phosphorescence.
Collapse
Affiliation(s)
- Jianxu Hu
- Materials Research Institute and School of Physics and Astronomy , Queen Mary University of London , Mile End Road , London E1 4NS , United Kingdom
| | - Peter B Wyatt
- Materials Research Institute and School of Biological and Chemical Sciences , Queen Mary University of London , Mile End Road , London E1 4NS , United Kingdom
| | - William P Gillin
- Materials Research Institute and School of Physics and Astronomy , Queen Mary University of London , Mile End Road , London E1 4NS , United Kingdom
- College of Physical Science and Technology , Sichuan University , Chengdu 610064 , China
| | - Huanqing Ye
- Materials Research Institute and School of Physics and Astronomy , Queen Mary University of London , Mile End Road , London E1 4NS , United Kingdom
| |
Collapse
|
32
|
Affiliation(s)
- Hauke C. Schmidt
- Departement ChemieUniversität Basel St. Johanns-Ring 19 4056 Basel Schweiz
| | | | - Oliver S. Wenger
- Departement ChemieUniversität Basel St. Johanns-Ring 19 4056 Basel Schweiz
| |
Collapse
|
33
|
Gray V, Küçüköz B, Edhborg F, Abrahamsson M, Moth-Poulsen K, Albinsson B. Singlet and triplet energy transfer dynamics in self-assembled axial porphyrin–anthracene complexes: towards supra-molecular structures for photon upconversion. Phys Chem Chem Phys 2018; 20:7549-7558. [DOI: 10.1039/c8cp00884a] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Singlet and triplet energy transfer dynamics in anthracene–ruthenium porphyrin complexes, and their application to photon upconversion.
Collapse
Affiliation(s)
- Victor Gray
- Chalmers University of Technology, Department of Chemistry and Chemical Engineering
- Gothenburg
- Sweden
| | - Betül Küçüköz
- Chalmers University of Technology, Department of Chemistry and Chemical Engineering
- Gothenburg
- Sweden
| | - Fredrik Edhborg
- Chalmers University of Technology, Department of Chemistry and Chemical Engineering
- Gothenburg
- Sweden
| | - Maria Abrahamsson
- Chalmers University of Technology, Department of Chemistry and Chemical Engineering
- Gothenburg
- Sweden
| | - Kasper Moth-Poulsen
- Chalmers University of Technology, Department of Chemistry and Chemical Engineering
- Gothenburg
- Sweden
| | - Bo Albinsson
- Chalmers University of Technology, Department of Chemistry and Chemical Engineering
- Gothenburg
- Sweden
| |
Collapse
|
34
|
Ivanov MV, Reilly N, Uhler B, Kokkin D, Rathore R, Reid SA. Cofacially Arrayed Polyfluorenes: Spontaneous Formation of π-Stacked Assemblies in the Gas Phase. J Phys Chem Lett 2017; 8:5272-5276. [PMID: 29020769 DOI: 10.1021/acs.jpclett.7b02627] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Understanding geometrical and size dependencies of through-space charge delocalization in multichromophoric systems is critical to model electron transfer and transport in materials and biomolecules. In this work, we examine the size evolution of hole delocalization in van der Waals clusters of fluorene (i.e., (F)n), where a range of geometries are possible, reflecting both π-stacking and C-H/π interactions. Using mass-selected two-color resonant two-photon ionization spectroscopy (2CR2PI), we measure electronic spectra and vertical ionization potentials (IPs) in the gas phase. Results are compared with model covalently linked assemblies (denoted Fn), exhibiting a sterically enforced cofacial (i.e., π-stacked) orientation of chromophores. For both systems, an inverse size dependence (i.e., 1/n) of IP vs cluster size is found. Surprisingly, the values for the two sets fall on the same line! This trend is examined via theory, which emphasizes the important role of π-stacking, and its geometrical dependencies, in the process of hole delocalization in multichromophoric assemblies.
Collapse
Affiliation(s)
- Maxim V Ivanov
- Department of Chemistry, Marquette University , Milwaukee, Wisconsin 53233, United States
| | - Neil Reilly
- Department of Chemistry, Marquette University , Milwaukee, Wisconsin 53233, United States
| | - Brandon Uhler
- Department of Chemistry, Marquette University , Milwaukee, Wisconsin 53233, United States
| | - Damian Kokkin
- Department of Chemistry, Marquette University , Milwaukee, Wisconsin 53233, United States
| | - Rajendra Rathore
- Department of Chemistry, Marquette University , Milwaukee, Wisconsin 53233, United States
| | - Scott A Reid
- Department of Chemistry, Marquette University , Milwaukee, Wisconsin 53233, United States
| |
Collapse
|
35
|
Kim Y, Wilson AJ, Jain PK. The Nature of Plasmonically Assisted Hot-Electron Transfer in a Donor–Bridge–Acceptor Complex. ACS Catal 2017. [DOI: 10.1021/acscatal.7b01318] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- Youngsoo Kim
- Department of Chemistry and §Materials Research Laboratory, University of Illinois Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Andrew J. Wilson
- Department of Chemistry and §Materials Research Laboratory, University of Illinois Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Prashant K. Jain
- Department of Chemistry and §Materials Research Laboratory, University of Illinois Urbana−Champaign, Urbana, Illinois 61801, United States
| |
Collapse
|
36
|
Carini M, Ruiz MP, Usabiaga I, Fernández JA, Cocinero EJ, Melle-Franco M, Diez-Perez I, Mateo-Alonso A. High conductance values in π-folded molecular junctions. Nat Commun 2017; 8:15195. [PMID: 28516950 PMCID: PMC5454372 DOI: 10.1038/ncomms15195] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Accepted: 03/09/2017] [Indexed: 12/20/2022] Open
Abstract
Folding processes play a crucial role in the development of function in biomacromolecules. Recreating this feature on synthetic systems would not only allow understanding and reproducing biological functions but also developing new functions. This has inspired the development of conformationally ordered synthetic oligomers known as foldamers. Herein, a new family of foldamers, consisting of an increasing number of anthracene units that adopt a folded sigmoidal conformation by a combination of intramolecular hydrogen bonds and aromatic interactions, is reported. Such folding process opens up an efficient through-space charge transport channel across the interacting anthracene moieties. In fact, single-molecule conductance measurements carried out on this series of foldamers, using the scanning tunnelling microscopy-based break-junction technique, reveal exceptionally high conductance values in the order of 10-1 G0 and a low length decay constant of 0.02 Å-1 that exceed the values observed in molecular junctions that make use of through-space charge transport pathways.
Collapse
Affiliation(s)
- Marco Carini
- POLYMAT, University of the Basque Country UPV/EHU, Avenida de Tolosa 72, E-20018 Donostia-San Sebastian, Spain
| | - Marta P. Ruiz
- Department of Materials Science and Physical Chemistry, Institute of Theoretical and Computational Chemistry, University of Barcelona, Martí I Franquès 1, 08028 Barcelona, Spain
- Institute for Bioengineering of Catalonia (IBEC), Martí I Franquès 1, 08028 Barcelona, Spain
| | - Imanol Usabiaga
- Departamento de Química Física, Facultad de Ciencia y Tecnología, Universidad del País Vasco (UPV/EHU), Apartado 644, E-48080 Bilbao, Spain
| | - José A. Fernández
- Departamento de Química Física, Facultad de Ciencia y Tecnología, Universidad del País Vasco (UPV/EHU), Apartado 644, E-48080 Bilbao, Spain
| | - Emilio J. Cocinero
- Departamento de Química Física, Facultad de Ciencia y Tecnología, Universidad del País Vasco (UPV/EHU), Apartado 644, E-48080 Bilbao, Spain
| | - Manuel Melle-Franco
- CICECO—Aveiro Institute of Materials, Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal
- Centro ALGORITMI, 4710-057 Braga, Portugal
| | - Ismael Diez-Perez
- Department of Materials Science and Physical Chemistry, Institute of Theoretical and Computational Chemistry, University of Barcelona, Martí I Franquès 1, 08028 Barcelona, Spain
- Institute for Bioengineering of Catalonia (IBEC), Martí I Franquès 1, 08028 Barcelona, Spain
| | - Aurelio Mateo-Alonso
- POLYMAT, University of the Basque Country UPV/EHU, Avenida de Tolosa 72, E-20018 Donostia-San Sebastian, Spain
- Ikerbasque, Basque Foundation for Science, Bilbao, Spain
| |
Collapse
|
37
|
Grieco C, Hirsekorn KF, Heitsch AT, Thomas AC, McAdon MH, Vanchura BA, Romanelli MM, Brehm LL, Leugers A, Sokolov AN, Asbury JB. Mechanisms of Energy Transfer and Enhanced Stability of Carbidonitride Phosphors for Solid-State Lighting. ACS APPLIED MATERIALS & INTERFACES 2017; 9:12547-12555. [PMID: 28319374 DOI: 10.1021/acsami.6b15323] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Phosphor-converted light emitting diodes (pcLEDs) produce white light through the use of phosphors that convert blue light emitted from the LED chip into green and red wavelengths. Understanding the mechanisms of degradation of the emission spectra and quantum yields of the phosphors used in pcLEDs is of critical importance to fully realize the potential of solid-state lighting as an energy efficient technology. Toward this end, time-resolved photoluminescence spectroscopy was used to identify the mechanistic origins of enhanced stability and luminescence efficiency that can be obtained from a series of carbidonitride red phosphors with varying degrees of substitutional carbon. The increasing substitution of carbon and oxygen in nitrogen positions of the carbidonitride phosphor (Sr2Si5N8-[(4x/3)+z]CxO3z/2:Eu2+) systematically changed the dimensions of the crystalline lattice. These structural changes caused a red shift and broadening of the emission spectra of the phosphors due to faster energy transfer from higher to lower energy emission sites. Surprisingly, in spite of broadening of the emission spectra, the quantum yield was maintained or increased with carbon substitution. Aging phosphors with lowered carbon content under conditions that accurately reflected thermal and optical stresses found in functioning pcLED packages led to spectral changes that were dependent on substitutional carbon content. Importantly, phosphors that contained optimal amounts of carbon and oxygen possessed luminescence spectra and quantum yields that did not undergo changes associated with aging and therefore provided a more stable color point for superior control of the emission properties of pcLED packages. These findings provide insights to guide continued development of phosphors for efficient and stable solid-state lighting materials and devices.
Collapse
Affiliation(s)
- Christopher Grieco
- Department of Chemistry, The Pennsylvania State University , University Park, Pennsylvania 16802, United States
| | - Kurt F Hirsekorn
- The Dow Chemical Company, Midland, Michigan 48674, United States
| | - Andrew T Heitsch
- The Dow Chemical Company, Midland, Michigan 48674, United States
| | - Alan C Thomas
- The Dow Chemical Company, Midland, Michigan 48674, United States
| | - Mark H McAdon
- The Dow Chemical Company, Midland, Michigan 48674, United States
| | - Britt A Vanchura
- The Dow Chemical Company, Midland, Michigan 48674, United States
| | | | - Lora L Brehm
- The Dow Chemical Company, Midland, Michigan 48674, United States
| | - Anne Leugers
- The Dow Chemical Company, Midland, Michigan 48674, United States
| | | | - John B Asbury
- Department of Chemistry, The Pennsylvania State University , University Park, Pennsylvania 16802, United States
| |
Collapse
|
38
|
Gong X, Young RM, Hartlieb KJ, Miller C, Wu Y, Xiao H, Li P, Hafezi N, Zhou J, Ma L, Cheng T, Goddard WA, Farha OK, Hupp JT, Wasielewski MR, Stoddart JF. Intramolecular Energy and Electron Transfer within a Diazaperopyrenium-Based Cyclophane. J Am Chem Soc 2017; 139:4107-4116. [DOI: 10.1021/jacs.6b13223] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
| | | | | | | | | | - Hai Xiao
- Materials
and Process Simulation Center, California Institute of Technology, Pasadena, California 91125, United States
| | | | | | | | | | - Tao Cheng
- Materials
and Process Simulation Center, California Institute of Technology, Pasadena, California 91125, United States
| | - William A. Goddard
- Materials
and Process Simulation Center, California Institute of Technology, Pasadena, California 91125, United States
| | - Omar K. Farha
- Department
of Chemistry, Faculty of Science, King Abdulaziz University, Jeddah 22254, Saudi Arabia
| | | | | | | |
Collapse
|
39
|
Rajagopal SK, Mallia AR, Hariharan M. Enhanced intersystem crossing in carbonylpyrenes. Phys Chem Chem Phys 2017; 19:28225-28231. [DOI: 10.1039/c7cp04834c] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Photoexcited state relaxation of carbonylpyrenes displays ultrafast intersystem crossing to generate near-unity triplet formation.
Collapse
Affiliation(s)
- Shinaj K. Rajagopal
- School of Chemistry
- Indian Institute of Science Education and Research Thiruvananthapuram
- Thiruvananthapuram 695551
- India
| | - Ajith R. Mallia
- School of Chemistry
- Indian Institute of Science Education and Research Thiruvananthapuram
- Thiruvananthapuram 695551
- India
| | - Mahesh Hariharan
- School of Chemistry
- Indian Institute of Science Education and Research Thiruvananthapuram
- Thiruvananthapuram 695551
- India
| |
Collapse
|
40
|
Khan FA, Wang D, Pemberton B, Talipov MR, Rathore R. Toroidal delocalization of a single electron through circularly-arrayed benzophenone chromophores in hexakis(4-benzoylphenyl)benzene. J Photochem Photobiol A Chem 2016. [DOI: 10.1016/j.jphotochem.2016.05.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
41
|
Reilly N, Ivanov M, Uhler B, Talipov M, Rathore R, Reid SA. First Experimental Evidence for the Diverse Requirements of Excimer vs Hole Stabilization in π-Stacked Assemblies. J Phys Chem Lett 2016; 7:3042-3045. [PMID: 27447947 DOI: 10.1021/acs.jpclett.6b01201] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Exciton formation and charge separation and transport are key dynamical events in a variety of functional polymeric materials and biological systems, including DNA. Beyond the necessary cofacial approach of a pair of aromatic molecules at van der Waals contact, the extent of overlap and necessary geometrical reorganization for optimal stabilization of an excimer vs dimer cation radical remain unresolved. Here, we compare experimentally the dynamics of excimer formation (via emission) and charge stabilization (via threshold ionization) of a novel covalently linked, cofacially stacked fluorene dimer (F2) with the unlinked van der Waals dimer of fluorene, that is, (F)2. Although the measured ionization potentials are identical, the excimeric state is stabilized by up to ∼30 kJ/mol in covalently linked F2. Supported by theory, this work demonstrates for the first time experimentally that optimal stabilization of an excimer requires a perfect sandwich-like geometry with maximal overlap, whereas hole stabilization in π-stacked aggregates is less geometrically restrictive.
Collapse
Affiliation(s)
- Neil Reilly
- Department of Chemistry, Marquette University , P.O. Box 1881, Milwaukee, Wisconsin 53233, United States
| | - Maxim Ivanov
- Department of Chemistry, Marquette University , P.O. Box 1881, Milwaukee, Wisconsin 53233, United States
| | - Brandon Uhler
- Department of Chemistry, Marquette University , P.O. Box 1881, Milwaukee, Wisconsin 53233, United States
| | - Marat Talipov
- Department of Chemistry, Marquette University , P.O. Box 1881, Milwaukee, Wisconsin 53233, United States
| | - Rajendra Rathore
- Department of Chemistry, Marquette University , P.O. Box 1881, Milwaukee, Wisconsin 53233, United States
| | - Scott A Reid
- Department of Chemistry, Marquette University , P.O. Box 1881, Milwaukee, Wisconsin 53233, United States
| |
Collapse
|
42
|
Talipov MR, Ivanov MV, Reid SA, Rathore R. Two's Company, Three's a Crowd: Exciton Localization in Cofacially Arrayed Polyfluorenes. J Phys Chem Lett 2016; 7:2915-2920. [PMID: 27409718 DOI: 10.1021/acs.jpclett.6b01268] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Understanding the mechanisms of long-range energy transfer through polychromophoric assemblies is critically important in photovoltaics and biochemical systems. Using a set of cofacially arrayed polyfluorenes (Fn), we investigate the mechanism of (singlet) exciton delocalization in π-stacked polychromophoric assemblies. Calculations reveal that effective stabilization of an excimeric state requires an ideal sandwich-like arrangement; yet surprisingly, emission spectroscopy indicates that exciton delocalization is limited to only two fluorene units for all n. Herein, we show that delocalization is determined by the interplay between the energetic gain from delocalization, which quickly saturates beyond two units in larger Fn, and an energetic penalty associated with structural reorganization, which increases linearly with n. With these insights, we propose a hopping mechanism for exciton transfer, based upon the presence of multiple excimeric tautomers of similar energy in larger polyfluorenes (n ≥ 4) together with the anticipated low thermal barrier of their interconversion.
Collapse
Affiliation(s)
- Marat R Talipov
- Department of Chemistry, Marquette University , P.O. Box 1881, Milwaukee, Wisconsin 53233, United States
| | - Maxim V Ivanov
- Department of Chemistry, Marquette University , P.O. Box 1881, Milwaukee, Wisconsin 53233, United States
| | - Scott A Reid
- Department of Chemistry, Marquette University , P.O. Box 1881, Milwaukee, Wisconsin 53233, United States
| | - Rajendra Rathore
- Department of Chemistry, Marquette University , P.O. Box 1881, Milwaukee, Wisconsin 53233, United States
| |
Collapse
|
43
|
Hu K, Blair AD, Piechota EJ, Schauer PA, Sampaio RN, Parlane FGL, Meyer GJ, Berlinguette CP. Kinetic pathway for interfacial electron transfer from a semiconductor to a molecule. Nat Chem 2016; 8:853-9. [DOI: 10.1038/nchem.2549] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Accepted: 05/10/2016] [Indexed: 11/09/2022]
|
44
|
Li X, Huang Z, Zavala R, Tang ML. Distance-Dependent Triplet Energy Transfer between CdSe Nanocrystals and Surface Bound Anthracene. J Phys Chem Lett 2016; 7:1955-1959. [PMID: 27164056 DOI: 10.1021/acs.jpclett.6b00761] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We investigate triplet energy transfer (TET) across variable-length aromatic oligo-p-phenylene and aliphatic bridges in a covalently linked CdSe nanocrystal (NC)-bridge-anthracene hybrid system. Photon upconversion measurements in saturated 9,10-diphenylanthracene hexane solutions under air-free conditions at room temperature provided the steady-state rate of TET (ket) across this interface. For flexible transmitters, ket is similar for different lengths of aliphatic bridges, suggesting that the ligands bend backward. For the rigid phenylene spacer, triplet sensitization of anthracene transmitter molecules by CdSe NCs shows a strong distance dependence, with a Dexter damping coefficient of 0.43 ± 0.07 Å(-1). The anthracene transmitter bound closest to the NC surface gave the highest quantum yield of 14.3% for the conversion of green to violet light, the current record for a hybrid platform.
Collapse
Affiliation(s)
- Xin Li
- Department of Chemistry, University of California, Riverside , Riverside, California 92521, United States
| | - Zhiyuan Huang
- Department of Chemistry, University of California, Riverside , Riverside, California 92521, United States
| | - Ramsha Zavala
- Department of Chemistry, University of California, Riverside , Riverside, California 92521, United States
| | - Ming Lee Tang
- Department of Chemistry, University of California, Riverside , Riverside, California 92521, United States
| |
Collapse
|
45
|
Talipov MR, Abdelwahed SH, Thakur K, Reid SA, Rathore R. From Wires to Cables: Attempted Synthesis of 1,3,5-Trifluorenylcyclohexane as a Platform for Molecular Cables. J Org Chem 2016; 81:1627-34. [PMID: 26783949 DOI: 10.1021/acs.joc.5b02792] [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
Multiple molecular wires braided together in a single assembly, termed as molecular cable, are promising next-generation materials for effective long-range charge transport. As an example of the platform for constructing molecular cables, 1,3,5-trifluorenylcyclohexane (TFC) and its difluorenyl analogues (DFCs) were systematically investigated both experimentally (X-ray crystallography) and theoretically (DFT calculations). Although the syntheses of DFCs were successfully achieved, the synthesis of TFC, which involved a similar intramolecular Friedel-Crafts cyclization as the last step, was unsuccessful. An exhaustive study of the conformational landscape of cyclohexane ring of TFC and DFCs revealed that TFC is a moderately strained molecule (∼17 kcal/mol), and computational studies of the reaction profile show that this steric strain, present in the transition state, is responsible for the unusually high (∼5 years) reaction half-life. A successful synthesis of TFC will require that the steric strain is introduced in multiple steps, and such alternative strategies are being currently explored.
Collapse
Affiliation(s)
- Marat R Talipov
- Department of Chemistry, Marquette University , P.O. Box 1881, Milwaukee, Wisconsin 53201-1881, United States
| | - Sameh H Abdelwahed
- Department of Chemistry, Marquette University , P.O. Box 1881, Milwaukee, Wisconsin 53201-1881, United States
| | - Khushabu Thakur
- Department of Chemistry, Marquette University , P.O. Box 1881, Milwaukee, Wisconsin 53201-1881, United States
| | - Scott A Reid
- Department of Chemistry, Marquette University , P.O. Box 1881, Milwaukee, Wisconsin 53201-1881, United States
| | - Rajendra Rathore
- Department of Chemistry, Marquette University , P.O. Box 1881, Milwaukee, Wisconsin 53201-1881, United States
| |
Collapse
|
46
|
Talipov MR, Boddeda A, Hossain MM, Rathore R. Quantitative generation of cation radicals and dications using aromatic oxidants: effect of added electrolyte on the redox potentials of aromatic electron donors. J PHYS ORG CHEM 2015. [DOI: 10.1002/poc.3523] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
- Marat R. Talipov
- Department of Chemistry; Marquette University; Milwaukee WI 53201-1881 USA
| | - Anitha Boddeda
- Department of Chemistry; Marquette University; Milwaukee WI 53201-1881 USA
| | | | - Rajendra Rathore
- Department of Chemistry; Marquette University; Milwaukee WI 53201-1881 USA
| |
Collapse
|
47
|
Mallia AR, Salini PS, Hariharan M. Nonparallel Stacks of Donor and Acceptor Chromophores Evade Geminate Charge Recombination. J Am Chem Soc 2015; 137:15604-7. [PMID: 26440563 DOI: 10.1021/jacs.5b08257] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We report a nonparallel stacked arrangement of donor–acceptor (D–A) pairs for prolonging the lifetime of photoinduced charge-separated states. Hydrogen–hydrogen steric repulsion in naphthalimide-naphthalene (NIN) dyad destabilizes the planar geometry between the constituent units in solution/ground state. Sterically imposed nonplanar geometry of the dyad allows the access of nonparallel arrangement of the donor and acceptor stacks having triclinic space group in the crystalline state. Antiparallel trajectory of excitons in nonparallel D–A stacks can result in lower probability of geminate charge recombination, upon photoexcitation, thereby resulting in a long-lived charge-separated state. Upon photoexcitation of the NIN dyad, electron transfer from naphthalene to the singlet excited state of naphthalimide moiety results in radical ion pair intermediates that survive >10,000-fold longer in the aggregated state (τcra > 1.2 ns) as compared to that of monomeric dyad (τcrm < 110 fs), monitored using femtosecond transient absorption spectroscopy.
Collapse
Affiliation(s)
- Ajith R Mallia
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram , CET Campus, Sreekaryam, Thiruvananthapuram, Kerala, India 695016
| | - P S Salini
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram , CET Campus, Sreekaryam, Thiruvananthapuram, Kerala, India 695016
| | - Mahesh Hariharan
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram , CET Campus, Sreekaryam, Thiruvananthapuram, Kerala, India 695016
| |
Collapse
|
48
|
An Z, Zheng C, Tao Y, Chen R, Shi H, Chen T, Wang Z, Li H, Deng R, Liu X, Huang W. Stabilizing triplet excited states for ultralong organic phosphorescence. NATURE MATERIALS 2015; 14:685-90. [PMID: 25849370 DOI: 10.1038/nmat4259] [Citation(s) in RCA: 816] [Impact Index Per Article: 90.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Accepted: 03/04/2015] [Indexed: 05/22/2023]
Abstract
The control of the emission properties of synthetic organic molecules through molecular design has led to the development of high-performance optoelectronic devices with tunable emission colours, high quantum efficiencies and efficient energy/charge transfer processes. However, the task of generating excited states with long lifetimes has been met with limited success, owing to the ultrafast deactivation of the highly active excited states. Here, we present a design rule that can be used to tune the emission lifetime of a wide range of luminescent organic molecules, based on effective stabilization of triplet excited states through strong coupling in H-aggregated molecules. Our experimental data revealed that luminescence lifetimes up to 1.35 s, which are several orders of magnitude longer than those of conventional organic fluorophores, can be realized under ambient conditions. These results outline a fundamental principle to design organic molecules with extended lifetimes of excited states, providing a major step forward in expanding the scope of organic phosphorescence applications.
Collapse
Affiliation(s)
- Zhongfu An
- 1] Key Laboratory for Organic Electronics and Information Displays &Institute of Advanced Materials, Jiangsu National Synergistic Innovation Center for Advanced Materials, Nanjing University of Posts and Telecommunications, Nanjing 210023, China [2] Key Laboratory of Flexible Electronics and Institute of Advanced Materials, Jiangsu National Synergistic Innovation Center for Advanced Materials, Nanjing Tech University, Nanjing 211816, China
| | - Chao Zheng
- Key Laboratory for Organic Electronics and Information Displays &Institute of Advanced Materials, Jiangsu National Synergistic Innovation Center for Advanced Materials, Nanjing University of Posts and Telecommunications, Nanjing 210023, China
| | - Ye Tao
- Key Laboratory for Organic Electronics and Information Displays &Institute of Advanced Materials, Jiangsu National Synergistic Innovation Center for Advanced Materials, Nanjing University of Posts and Telecommunications, Nanjing 210023, China
| | - Runfeng Chen
- 1] Key Laboratory for Organic Electronics and Information Displays &Institute of Advanced Materials, Jiangsu National Synergistic Innovation Center for Advanced Materials, Nanjing University of Posts and Telecommunications, Nanjing 210023, China [2] Key Laboratory of Flexible Electronics and Institute of Advanced Materials, Jiangsu National Synergistic Innovation Center for Advanced Materials, Nanjing Tech University, Nanjing 211816, China
| | - Huifang Shi
- Key Laboratory of Flexible Electronics and Institute of Advanced Materials, Jiangsu National Synergistic Innovation Center for Advanced Materials, Nanjing Tech University, Nanjing 211816, China
| | - Ting Chen
- Key Laboratory for Organic Electronics and Information Displays &Institute of Advanced Materials, Jiangsu National Synergistic Innovation Center for Advanced Materials, Nanjing University of Posts and Telecommunications, Nanjing 210023, China
| | - Zhixiang Wang
- Key Laboratory for Organic Electronics and Information Displays &Institute of Advanced Materials, Jiangsu National Synergistic Innovation Center for Advanced Materials, Nanjing University of Posts and Telecommunications, Nanjing 210023, China
| | - Huanhuan Li
- Key Laboratory for Organic Electronics and Information Displays &Institute of Advanced Materials, Jiangsu National Synergistic Innovation Center for Advanced Materials, Nanjing University of Posts and Telecommunications, Nanjing 210023, China
| | - Renren Deng
- Department of Chemistry, National University of Singapore, Singapore 117543, Singapore
| | - Xiaogang Liu
- 1] Department of Chemistry, National University of Singapore, Singapore 117543, Singapore [2] Institute of Materials Research and Engineering, Agency for Science, Technology and Research, Singapore 117602, Singapore
| | - Wei Huang
- 1] Key Laboratory for Organic Electronics and Information Displays &Institute of Advanced Materials, Jiangsu National Synergistic Innovation Center for Advanced Materials, Nanjing University of Posts and Telecommunications, Nanjing 210023, China [2] Key Laboratory of Flexible Electronics and Institute of Advanced Materials, Jiangsu National Synergistic Innovation Center for Advanced Materials, Nanjing Tech University, Nanjing 211816, China
| |
Collapse
|
49
|
Zhang X, Shen W, Sun H, He R, Li M. Identifying efficient blue-phosphorescent polymer light-emitting diode host materials based on carbazole derivatives with C/Si-centered substituents using density functional theory. J Mol Model 2015; 21:178. [PMID: 26104849 DOI: 10.1007/s00894-015-2725-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Accepted: 06/08/2015] [Indexed: 11/29/2022]
Abstract
Two series of carbazole derivatives were designed and studied that could potentially be used in polymer light-emitting diodes (PLEDs) as host molecules. These carbazole-based host molecules incorporated substituents with C or Si at their centers at the 3- and 6-positions on the carbazole moiety. Density functional theory calculations were performed to investigate the influence of the substituent on energy and charge transfer, and to predict whether each molecule could act as an effective host material in PLEDs. The results show that, for the series in which the carbazole moiety is linked to the substituent via the central C/Si atom ("cbz-sub series"), triplet-state electron transitions and triplet excitons arise from the carbazole moiety. Members of the cbz-sub series also exhibited higher triplet energies (ET) than the series in which the carbazole moiety is linked to the C/Si-centered substituent via an extra phenyl group ("cbz-ph-sub series"). Moreover, members of the cbz-sub series presented strong molecular orbital interactions and suitable singlet and triplet energy differences (ΔEST). Further investigations showed that, in each series, the presence of an Si atom was more likely to inhibit charge and exciton delocalization, and inserting a methyl or tert-butyl group at the 2- and 7-position, respectively, of the carbazole moiety in the cbz-ph-sub molecules improved their ET values and led to clear intramolecular charge-transfer character. A comparison of the energies of host and guest molecules showed that all of the molecules designed in this work are suitable for use with blue-light guest materials.
Collapse
Affiliation(s)
- Xiaguang Zhang
- School of Chemistry and Chemical Engineering, Southwest University, Chongqing, 400715, People's Republic of China
| | | | | | | | | |
Collapse
|
50
|
Delor M, Sazanovich IV, Towrie M, Weinstein JA. Probing and Exploiting the Interplay between Nuclear and Electronic Motion in Charge Transfer Processes. Acc Chem Res 2015; 48:1131-9. [PMID: 25789559 DOI: 10.1021/ar500420c] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The Born-Oppenheimer approximation refers to the assumption that the nuclear and electronic wave functions describing a molecular system evolve and can be determined independently. It is now well-known that this approximation often breaks down and that nuclear-electronic (vibronic) coupling contributes greatly to the ultrafast photophysics and photochemistry observed in many systems ranging from simple molecules to biological organisms. In order to probe vibronic coupling in a time-dependent manner, one must use spectroscopic tools capable of correlating the motions of electrons and nuclei on an ultrafast time scale. Recent developments in nonlinear multidimensional electronic and vibrational spectroscopies allow monitoring both electronic and structural factors with unprecedented time and spatial resolution. In this Account, we present recent studies from our group that make use of different variants of frequency-domain transient two-dimensional infrared (T-2DIR) spectroscopy, a pulse sequence combining electronic and vibrational excitations in the form of a UV-visible pump, a narrowband (12 cm(-1)) IR pump, and a broadband (400 cm(-1)) IR probe. In the first example, T-2DIR is used to directly compare vibrational dynamics in the ground and relaxed electronic excited states of Re(Cl)(CO)3(4,4'-diethylester-2,2'-bipyridine) and Ru(4,4'-diethylester-2,2'-bipyridine)2(NCS)2, prototypical charge transfer complexes used in photocatalytic CO2 reduction and electron injection in dye-sensitized solar cells. The experiments show that intramolecular vibrational redistribution (IVR) and vibrational energy transfer (VET) are up to an order of magnitude faster in the triplet charge transfer excited state than in the ground state. These results show the influence of electronic arrangement on vibrational coupling patterns, with direct implications for vibronic coupling mechanisms in charge transfer excited states. In the second example, we show unambiguously that electronic and vibrational movement are coupled in a donor-bridge-acceptor complex based on a Pt(II) trans-acetylide design motif. Time-resolved IR (TRIR) spectroscopy reveals that the rate of electron transfer (ET) is highly dependent on the amount of excess energy localized on the bridge following electronic excitation. Using an adaptation of T-2DIR, we are able to selectively perturb bridge-localized vibrational modes during charge separation, resulting in the donor-acceptor charge separation pathway being completely switched off, with all excess energy redirected toward the formation of a long-lived intraligand triplet state. A series of control experiments reveal that this effect is mode specific: it is only when the high-frequency bridging C≡C stretching mode is pumped that radical changes in photoproduct yields are observed. These experiments therefore suggest that one may perturb electronic movement by stimulating structural motion along the reaction coordinate using IR light. These studies add to a growing body of evidence suggesting that controlling the pathways and efficiency of charge transfer may be achieved through synthetic and perturbative approaches aiming to modulate vibronic coupling. Achieving such control would represent a breakthrough for charge transfer-based applications such as solar energy conversion and molecular electronics.
Collapse
Affiliation(s)
- Milan Delor
- Department
of Chemistry, University of Sheffield, Sheffield S3 7HF, U.K
| | - Igor V. Sazanovich
- Central
Laser Facility, Research Complex at Harwell, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, STFC, Chilton, Oxfordshire OX11 0QX, U.K
| | - Michael Towrie
- Central
Laser Facility, Research Complex at Harwell, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, STFC, Chilton, Oxfordshire OX11 0QX, U.K
| | | |
Collapse
|