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Attwood M, Xu X, Newns M, Meng Z, Ingle RA, Wu H, Chen X, Xu W, Ng W, Abiola TT, Stavros VG, Oxborrow M. N-Heteroacenes as an Organic Gain Medium for Room-Temperature Masers. CHEMISTRY OF MATERIALS : A PUBLICATION OF THE AMERICAN CHEMICAL SOCIETY 2023; 35:4498-4509. [PMID: 37332679 PMCID: PMC10268955 DOI: 10.1021/acs.chemmater.3c00640] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 05/04/2023] [Indexed: 06/20/2023]
Abstract
The development of future quantum devices such as the maser, i.e., the microwave analog of the laser, could be well-served by the exploration of chemically tunable organic materials. Current iterations of room-temperature organic solid-state masers are composed of an inert host material that is doped with a spin-active molecule. In this work, we systematically modulated the structure of three nitrogen-substituted tetracene derivatives to augment their photoexcited spin dynamics and then evaluated their potential as novel maser gain media by optical, computational, and electronic paramagnetic resonance (EPR) spectroscopy. To facilitate these investigations, we adopted an organic glass former, 1,3,5-tri(1-naphthyl)benzene to act as a universal host. These chemical modifications impacted the rates of intersystem crossing, triplet spin polarization, triplet decay, and spin-lattice relaxation, leading to significant consequences on the conditions required to surpass the maser threshold.
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Affiliation(s)
- Max Attwood
- Department
of Materials, Imperial College London, South Kensington Campus, Exhibition
Road, London SW7 2AZ, U.K.
| | - Xiaotian Xu
- Department
of Materials, Imperial College London, South Kensington Campus, Exhibition
Road, London SW7 2AZ, U.K.
| | - Michael Newns
- Department
of Materials, Imperial College London, South Kensington Campus, Exhibition
Road, London SW7 2AZ, U.K.
| | - Zhu Meng
- Molecular
Sciences Research Hub, Department of Chemistry, Imperial College London, White City Campus, 82 Wood Lane, London W12 0BZ, U.K.
| | - Rebecca A. Ingle
- Department
of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, U.K.
| | - Hao Wu
- Center
for Quantum Technology Research and Key Laboratory of Advanced Optoelectronic
Quantum Architecture and Measurements, School of Physics, Beijing Institute of Technology, Beijing 100081, China
| | - Xi Chen
- Department
of Materials, Imperial College London, South Kensington Campus, Exhibition
Road, London SW7 2AZ, U.K.
- Department
of Computer Science, University of Southern
California, Los Angeles, California 90089, United States
| | - Weidong Xu
- Molecular
Sciences Research Hub, Department of Chemistry, Imperial College London, White City Campus, 82 Wood Lane, London W12 0BZ, U.K.
| | - Wern Ng
- Department
of Materials, Imperial College London, South Kensington Campus, Exhibition
Road, London SW7 2AZ, U.K.
| | - Temitope T. Abiola
- Department
of Chemistry, University of Toronto, 80 St. George Street, Toronto M5S 3H6, Canada
| | | | - Mark Oxborrow
- Department
of Materials, Imperial College London, South Kensington Campus, Exhibition
Road, London SW7 2AZ, U.K.
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Wei YC, Chen BH, Ye RS, Huang HW, Su JX, Lin CY, Hodgkiss J, Hsu LY, Chi Y, Chen K, Lu CH, Yang SD, Chou PT. Excited-State THz Vibrations in Aggregates of Pt II Complexes Contribute to the Enhancement of Near-Infrared Emission Efficiencies. Angew Chem Int Ed Engl 2023; 62:e202300815. [PMID: 36825300 DOI: 10.1002/anie.202300815] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Revised: 02/23/2023] [Accepted: 02/23/2023] [Indexed: 02/25/2023]
Abstract
The exploration of deactivation mechanisms for near-infrared(NIR)-emissive organic molecules has been a key issue in chemistry, materials science and molecular biology. In this study, based on transient absorption spectroscopy and transient grating photoluminescence spectroscopy, we demonstrate that the aggregated PtII complex 4H (efficient NIR emitter) exhibits collective out-of-plane motions with a frequency of 32 cm-1 (0.96 THz) in the excited states. Importantly, similar THz characteristics were also observed in analogous PtII complexes with prominent NIR emission efficiency. The conservation of THz motions enables excited-state deactivation to proceed along low-frequency vibrational coordinates, contributing to the suppression of nonradiative decay and remarkable NIR emission. These novel results highlight the significance of excited-state vibrations in nonradiative processes, which serve as a benchmark for improving device performance.
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Affiliation(s)
- Yu-Chen Wei
- Department of Chemistry, National Taiwan University, Taipei, 10617, Taiwan
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, 10617, Taiwan
| | - Bo-Han Chen
- Institute of Photonics Technologies, National Tsing Hua University, Hsinchu, 30013, Taiwan
| | - Ren-Siang Ye
- Institute of Photonics Technologies, National Tsing Hua University, Hsinchu, 30013, Taiwan
| | - Hsing-Wei Huang
- Institute of Photonics Technologies, National Tsing Hua University, Hsinchu, 30013, Taiwan
| | - Jia-Xuan Su
- Institute of Photonics Technologies, National Tsing Hua University, Hsinchu, 30013, Taiwan
| | - Chao-Yang Lin
- Robinson Research Institute, Faculty of Engineering, Victoria University of Wellington, Wellington, 6012, New Zealand
| | - Justin Hodgkiss
- MacDiarmid Institute for Advanced Materials and Nanotechnology, Wellington, 6010, New Zealand
| | - Lian-Yan Hsu
- Department of Chemistry, National Taiwan University, Taipei, 10617, Taiwan
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, 10617, Taiwan
- National Center for Theoretical Sciences, Taipei, 10617, Taiwan
| | - Yun Chi
- Department of Materials Science and Engineering, Department of Chemistry, and Center of Super-Diamond and Advanced Films (COSDAF), City University of Hong Kong, Hong Kong SAR, Hong Kong
| | - Kai Chen
- Robinson Research Institute, Faculty of Engineering, Victoria University of Wellington, Wellington, 6012, New Zealand
- MacDiarmid Institute for Advanced Materials and Nanotechnology, Wellington, 6010, New Zealand
- The Dodd-Walls Centre for Photonic and Quantum Technologies, Dunedin, 9016, New Zealand
| | - Chih-Hsuan Lu
- Institute of Photonics Technologies, National Tsing Hua University, Hsinchu, 30013, Taiwan
| | - Shang-Da Yang
- Institute of Photonics Technologies, National Tsing Hua University, Hsinchu, 30013, Taiwan
| | - Pi-Tai Chou
- Department of Chemistry, National Taiwan University, Taipei, 10617, Taiwan
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3
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Wei Y, Chen B, Ye R, Huang H, Su J, Lin C, Hodgkiss J, Hsu L, Chi Y, Chen K, Lu C, Yang S, Chou P. Excited‐State THz Vibrations in Aggregates of Pt
II
Complexes Contribute to the Enhancement of Near‐Infrared Emission Efficiencies**. Angew Chem Int Ed Engl 2023. [DOI: 10.1002/ange.202300815] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/16/2023]
Affiliation(s)
- Yu‐Chen Wei
- Department of Chemistry National Taiwan University Taipei 10617 Taiwan
- Institute of Atomic and Molecular Sciences Academia Sinica Taipei 10617 Taiwan
| | - Bo‐Han Chen
- Institute of Photonics Technologies National Tsing Hua University Hsinchu 30013 Taiwan
| | - Ren‐Siang Ye
- Institute of Photonics Technologies National Tsing Hua University Hsinchu 30013 Taiwan
| | - Hsing‐Wei Huang
- Institute of Photonics Technologies National Tsing Hua University Hsinchu 30013 Taiwan
| | - Jia‐Xuan Su
- Institute of Photonics Technologies National Tsing Hua University Hsinchu 30013 Taiwan
| | - Chao‐Yang Lin
- Robinson Research Institute Faculty of Engineering Victoria University of Wellington Wellington 6012 New Zealand
| | - Justin Hodgkiss
- MacDiarmid Institute for Advanced Materials and Nanotechnology Wellington 6010 New Zealand
| | - Lian‐Yan Hsu
- Department of Chemistry National Taiwan University Taipei 10617 Taiwan
- Institute of Atomic and Molecular Sciences Academia Sinica Taipei 10617 Taiwan
- National Center for Theoretical Sciences Taipei 10617 Taiwan
| | - Yun Chi
- Department of Materials Science and Engineering Department of Chemistry and Center of Super-Diamond and Advanced Films (COSDAF) City University of Hong Kong Hong Kong SAR Hong Kong
| | - Kai Chen
- Robinson Research Institute Faculty of Engineering Victoria University of Wellington Wellington 6012 New Zealand
- MacDiarmid Institute for Advanced Materials and Nanotechnology Wellington 6010 New Zealand
- The Dodd-Walls Centre for Photonic and Quantum Technologies Dunedin 9016 New Zealand
| | - Chih‐Hsuan Lu
- Institute of Photonics Technologies National Tsing Hua University Hsinchu 30013 Taiwan
| | - Shang‐Da Yang
- Institute of Photonics Technologies National Tsing Hua University Hsinchu 30013 Taiwan
| | - Pi‐Tai Chou
- Department of Chemistry National Taiwan University Taipei 10617 Taiwan
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4
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Posenitskiy E, Rapacioli M, Lemoine D, Spiegelman F. Theoretical investigation of the electronic relaxation in highly excited chrysene and tetracene: The effect of armchair vs zigzag edge. J Chem Phys 2020; 152:074306. [PMID: 32087654 DOI: 10.1063/1.5135369] [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
Non-adiabatic molecular dynamics of neutral chrysene and tetracene molecules is investigated using Tully's fewest switches surface hopping algorithm coupled to the time-dependent density functional based tight-binding (TD-DFTB) method for electronic structure calculations. We first assess the performance of two DFTB parameter sets based on the computed TD-DFTB absorption spectra. The main focus is given to the analysis of the electronic relaxation from the brightest excited state following absorption of a UV photon. We determine the dynamical relaxation times and discuss the underlying mechanisms. Our results show that the electronic population of the brightest excited singlet state in armchair-edge chrysene decays an order-of-magnitude faster than the one in zigzag-edge tetracene. This is correlated with a qualitatively similar difference of energy gaps between the brightest state and the state lying just below in energy, which is also consistent with our previous study on polyacenes.
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Affiliation(s)
- Evgeny Posenitskiy
- Laboratoire Collisions Agrégats et Réactivité (LCAR), IRSAMC UMR5589, Université de Toulouse (UPS) and CNRS, 118 Route de Narbonne, F-31062 Toulouse, France
| | - Mathias Rapacioli
- Laboratoire de Chimie et Physique Quantiques (LCPQ), IRSAMC UMR5626, Université de Toulouse (UPS) and CNRS, 118 Route de Narbonne, F-31062 Toulouse, France
| | - Didier Lemoine
- Laboratoire Collisions Agrégats et Réactivité (LCAR), IRSAMC UMR5589, Université de Toulouse (UPS) and CNRS, 118 Route de Narbonne, F-31062 Toulouse, France
| | - Fernand Spiegelman
- Laboratoire de Chimie et Physique Quantiques (LCPQ), IRSAMC UMR5626, Université de Toulouse (UPS) and CNRS, 118 Route de Narbonne, F-31062 Toulouse, France
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5
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Posenitskiy E, Rapacioli M, Lepetit B, Lemoine D, Spiegelman F. Non-adiabatic molecular dynamics investigation of the size dependence of the electronic relaxation in polyacenes. Phys Chem Chem Phys 2019; 21:12139-12149. [DOI: 10.1039/c9cp00603f] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Electronic relaxation from the brightest excited state has been investigated for neutral polyacenes ranging in size from naphthalene to heptacene.
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Affiliation(s)
- Evgeny Posenitskiy
- Laboratoire Collisions Agrégats et Réactivité (LCAR)
- IRSAMC UMR5589
- Université de Toulouse (UPS) and CNRS
- F-31062 Toulouse
- France
| | - Mathias Rapacioli
- Laboratoire de Chimie et Physique Quantiques (LCPQ)
- IRSAMC UMR5626
- Université de Toulouse (UPS) and CNRS
- F-31062 Toulouse
- France
| | - Bruno Lepetit
- Laboratoire Collisions Agrégats et Réactivité (LCAR)
- IRSAMC UMR5589
- Université de Toulouse (UPS) and CNRS
- F-31062 Toulouse
- France
| | - Didier Lemoine
- Laboratoire Collisions Agrégats et Réactivité (LCAR)
- IRSAMC UMR5589
- Université de Toulouse (UPS) and CNRS
- F-31062 Toulouse
- France
| | - Fernand Spiegelman
- Laboratoire de Chimie et Physique Quantiques (LCPQ)
- IRSAMC UMR5626
- Université de Toulouse (UPS) and CNRS
- F-31062 Toulouse
- France
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6
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Barsotti F, Ghigo G, Berto S, Vione D. The nature of the light absorption and emission transitions of 4-hydroxybenzophenone in different solvents. A combined computational and experimental study. Photochem Photobiol Sci 2018; 16:527-538. [PMID: 28102421 DOI: 10.1039/c6pp00272b] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The photophysics and photochemistry of 4-hydroxybenzophenone (4HOBP) are interesting because they can give some insight into the behavior of humic material. Here we show that 4HOBP has a number of fluorescence peaks: (i) an intense one at excitation/emission wavelengths Ex/Em ∼ 200-230/280-370 nm, likely due to an excitation transition from S0 to S5 or S6, followed by S2 → S0 in emission (Sn denotes the singlet states of 4HOBP); (ii) a minor peak at Ex/Em ∼ 270-300/320-360 nm (S0 → S2 in absorption and S2 → S0 in emission), and (iii) very interesting signals in the typical emission region of humic substances, most notably at Ex/Em ∼ 200-220/400-500 nm and Ex/Em ∼ 260-280/400-470 nm (in both cases the emission corresponded to an S1 → S0 transition). The peak (i) (Ex/Em ∼ 200-230/280-370 nm) is quite intense at low 4HOBP concentration values, but it undergoes an effective inner-filter phenomenon. Remarkably, 4HOBP shows fluorescence peaks that arise from S2 → S0 transitions and that do not follow Kasha's rule. Fluorescence is observed in aprotic or poorly protic solvents, and to a lesser extent in aqueous solution. The excited states of 4HOBP, and most notably 4HOBP-S1, are much stronger acids than 4HOBP-S0. Therefore, excited 4HOBP is quickly deprotonated to 4OBP--S0 in ∼neutral solution, with a considerable loss of the fluorescence properties. Higher fluorescence intensity can be observed under acidic conditions, where excited-state deprotonation is less effective, and in basic solution where the dissociated 4OBP--S0 form prevails as the ground state. The excited states of 4OBP- are formed directly upon radiation absorption, and being weak bases they do not undergo important acid-base equilibria. Therefore, they can undergo radiational deactivation to produce significant fluorescence emission.
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Affiliation(s)
- Francesco Barsotti
- Dipartimento di Chimica, Università di Torino, Via Giuria 5, 10125 Torino, Italy.
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Sun Q, Dereka B, Vauthey E, Lawson Daku LM, Hauser A. Ultrafast transient IR spectroscopy and DFT calculations of ruthenium(ii) polypyridyl complexes. Chem Sci 2016; 8:223-230. [PMID: 28451169 PMCID: PMC5308284 DOI: 10.1039/c6sc01220e] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Accepted: 08/10/2016] [Indexed: 12/23/2022] Open
Abstract
Ultrafast time-resolved infrared spectroscopy of [Ru(bpy)3]2+ (bpy = 2,2'-bipyridine), [Ru(mbpy)3]2+ (mbpy = 6-methyl-2,2'-bipyridine) and [Ru(mphen)3]2+ (mphen = 2-methyl-1,10'-phenanthroline) in deuterated acetonitrile serves to elucidate the evolution of the system following pulsed excitation into the 1MLCT band at 400 nm. While for [Ru(bpy)3]2+ no intermediate state can be evidenced for the relaxation of the corresponding 3MLCT state back to the ground state, for [Ru(mbpy)3]2+ and [Ru(mphen)3]2+ an intermediate state with a lifetime of about 400 ps is observed. The species associated IR difference spectra of this state are in good agreement with the calculated difference spectra of the lowest energy 3dd state using DFT. The calculated potential energy curves for all the complexes in the triplet manifold along the metal-ligand distance show that for [Ru(bpy)3]2+ the 3dd state is at a higher energy than the 3MLCT state and that there is a substantial barrier between the two minima. For [Ru(mbpy)3]2+ and [Ru(mphen)3]2+, the 3dd state is at a lower energy than the 3MLCT state.
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Affiliation(s)
- Qinchao Sun
- Département de Chimie Physique , Université de Genève , 30 Quai Ernest-Ansermet , 1211 Genève , Switzerland .
| | - Bogdan Dereka
- Département de Chimie Physique , Université de Genève , 30 Quai Ernest-Ansermet , 1211 Genève , Switzerland .
| | - Eric Vauthey
- Département de Chimie Physique , Université de Genève , 30 Quai Ernest-Ansermet , 1211 Genève , Switzerland .
| | - Latévi M Lawson Daku
- Département de Chimie Physique , Université de Genève , 30 Quai Ernest-Ansermet , 1211 Genève , Switzerland .
| | - Andreas Hauser
- Département de Chimie Physique , Université de Genève , 30 Quai Ernest-Ansermet , 1211 Genève , Switzerland .
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