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Tauchi D, Kanno K, Hasegawa M, Mazaki Y, Tsubaki K, Sugiura KI, Shiga T, Mori S, Nishikawa H. Aggregation-induced enhanced fluorescence emission of chiral Zn(II) complexes coordinated by Schiff-base type binaphthyl ligands. Dalton Trans 2024; 53:8926-8933. [PMID: 38687172 DOI: 10.1039/d4dt00903g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2024]
Abstract
A pair of novel chiral Zn(II) complexes coordinated by Schiff-base type ligands derived from BINOL (1,1'-bi-2-naphthol), R-/S-Zn, were synthesized. X-ray crystallography revealed the presence of two crystallographically independent complexes; one has a distorted trigonal-bipyramidal structure coordinated by two binaphthyl ligands and one disordered methanol molecule (molecule A), while the other has a distorted tetrahedral structure coordinated by two binaphthyl ligands (molecule B). Numerous CH⋯π and CH⋯O interactions were identified, contributing to the formation of a 3-dimensional rigid network structure. Both R-/S-Zn exhibited fluorescence in both CH2Cl2 solutions and powder samples, with the photoluminescence quantum yields (PLQYs) of powder samples being twice as large as those in solutions, indicating aggregation-induced enhanced emission (AIEE). The AIEE properties were attributed to the restraint of the molecular motion arising from the 3-dimensional intermolecular interactions. CD and CPL spectra were observed for R-/S-Zn in both solutions and powders. The dissymmetry factors, gabs and gCPL values, were within the order of 10-3 to 10-4 magnitudes, comparable to those reported for chiral Zn(II) complexes in previous studies.
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Affiliation(s)
- Daiki Tauchi
- Graduate School of Science and Engineering, Ibaraki University, 2-1-1 Bunkyo, Mito, Ibaraki 310-8512, Japan.
| | - Katsuya Kanno
- Graduate School of Science and Engineering, Ibaraki University, 2-1-1 Bunkyo, Mito, Ibaraki 310-8512, Japan.
| | - Masashi Hasegawa
- Graduate School of Science, Kitasato University, Kanagawa 252-0373, Japan
| | - Yasuhiro Mazaki
- Graduate School of Science, Kitasato University, Kanagawa 252-0373, Japan
| | - Kazunori Tsubaki
- Graduate School of Life and Environmental Sciences, Kyoto Prefectural University, Kyoto 606-8522, Japan
| | - Ken-Ichi Sugiura
- Graduate School of Science, Tokyo Metropolitan University, Tokyo, 192-0397, Japan
| | - Takuya Shiga
- Faculty of Pure and Applied Sciences, University of Tsukuba, Tsukuba 305-8577, Japan
| | - Seiji Mori
- Graduate School of Science and Engineering, Ibaraki University, 2-1-1 Bunkyo, Mito, Ibaraki 310-8512, Japan.
| | - Hiroyuki Nishikawa
- Graduate School of Science and Engineering, Ibaraki University, 2-1-1 Bunkyo, Mito, Ibaraki 310-8512, Japan.
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Ikeshita M, Ma SC, Muller G, Naota T. Linker-dependent control of the chiroptical properties of polymethylene-vaulted trans-bis[(β-iminomethyl)naphthoxy]platinum(II) complexes. Dalton Trans 2024; 53:7775-7787. [PMID: 38619916 DOI: 10.1039/d4dt00273c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/17/2024]
Abstract
The effects of polymethylene bridges on the chiroptical properties of trans-bis[(β-iminomethyl)naphthoxy]platinum(II) platforms were examined both experimentally and theoretically using newly designed planar chiral Pt analogues (1) having three-dimensional superstructures. A series of optically pure polymethylene-vaulted Pt complexes (R)- and (S)-1 were synthesized and characterized with regard to the chiroptical behaviour of the trans-bis[(β-iminomethyl)naphthoxy]platinum(II) platforms. These complexes were found to exhibit structure-dependent chiroptical characteristics in solution, such that the absolute values of specific rotation, the circular dichroism dissymmetry factor (gabs) and the circularly polarized luminescence dissymmetry factor (glum) all increased upon shortening the polymethylene bridges. Density functional theory and time dependent density functional theory calculations were used to analyse vaulted and non-vaulted complexes, which demonstrated that the present linker-dependent chiroptical properties resulted from constraint-induced changes in the square planar Pt coordination centres rather than from chiral distortion along the coordination platforms.
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Affiliation(s)
- Masahiro Ikeshita
- Department of Chemistry, Graduate School of Engineering Science, Osaka University, Machikaneyama, Toyonaka, Osaka 560-8531, Japan.
- Department of Applied Molecular Chemistry, College of Industrial Technology, Nihon University, Narashino, Chiba 275-8575, Japan.
| | - Shing Cho Ma
- Department of Chemistry, San José State University, One Washington Square, San José, California 95192-0101, USA.
| | - Gilles Muller
- Department of Chemistry, San José State University, One Washington Square, San José, California 95192-0101, USA.
| | - Takeshi Naota
- Department of Chemistry, Graduate School of Engineering Science, Osaka University, Machikaneyama, Toyonaka, Osaka 560-8531, Japan.
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Ikeshita M, Watanabe S, Suzuki S, Tanaka S, Hattori S, Shinozaki K, Imai Y, Tsuno T. Circularly polarized phosphorescence with a large dissymmetry factor from a helical platinum(II) complex. Chem Commun (Camb) 2024; 60:2413-2416. [PMID: 38323590 DOI: 10.1039/d3cc06293g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2024]
Abstract
A chiral platinum(II) complex with a helical Schiff-base [4]helicene ligand exhibits intense red circularly polarized phosphorescence (CPP) with a glum of 0.010 in the dilute solution state. The intense CPP was caused by a change in the electronic transition character based on the induction of the helical structure.
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Affiliation(s)
- Masahiro Ikeshita
- Department of Applied Molecular Chemistry, College of Industrial Technology, Nihon University, Narashino, Chiba 275-8575, Japan.
| | - Shinya Watanabe
- Department of Applied Molecular Chemistry, College of Industrial Technology, Nihon University, Narashino, Chiba 275-8575, Japan.
| | - Seika Suzuki
- Department of Applied Chemistry, Faculty of Science and Engineering, Kindai University, 3-4-1 Kowakae, Higashi-Osaka, Osaka 577-8502, Japan.
| | - Shota Tanaka
- Graduate School of Nanobioscience, Yokohama City University, 22-2 Seto, Kanazawa-ku, Yokohama 236-0027, Japan
| | - Shingo Hattori
- Graduate School of Nanobioscience, Yokohama City University, 22-2 Seto, Kanazawa-ku, Yokohama 236-0027, Japan
| | - Kazuteru Shinozaki
- Graduate School of Nanobioscience, Yokohama City University, 22-2 Seto, Kanazawa-ku, Yokohama 236-0027, Japan
| | - Yoshitane Imai
- Department of Applied Chemistry, Faculty of Science and Engineering, Kindai University, 3-4-1 Kowakae, Higashi-Osaka, Osaka 577-8502, Japan.
| | - Takashi Tsuno
- Department of Applied Molecular Chemistry, College of Industrial Technology, Nihon University, Narashino, Chiba 275-8575, Japan.
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Kitzmann WR, Freudenthal J, Reponen APM, VanOrman ZA, Feldmann S. Fundamentals, Advances, and Artifacts in Circularly Polarized Luminescence (CPL) Spectroscopy. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2302279. [PMID: 37658497 DOI: 10.1002/adma.202302279] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2023] [Revised: 05/06/2023] [Indexed: 09/03/2023]
Abstract
Objects are chiral when they cannot be superimposed with their mirror image. Materials can emit chiral light with an excess of right- or left-handed circular polarization. This circularly polarized luminescence (CPL) is key to promising future applications, such as highly efficient displays, holography, sensing, enantiospecific discrimination, synthesis of drugs, quantum computing, and cryptography. Here, a practical guide to CPL spectroscopy is provided. First, the fundamentals of the technique are laid out and a detailed account of recent experimental advances to achieve highly sensitive and accurate measurements is given, including all corrections required to obtain reliable results. Then the most common artifacts and pitfalls are discussed, especially for the study of thin films, for example, based on molecules, polymers, or halide perovskites, as opposed to dilute solutions of emitters. To facilitate the adoption by others, custom operating software is made publicly available, equipping the reader with the tools needed for successful and accurate CPL determination.
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Affiliation(s)
- Winald R Kitzmann
- Department of Chemistry, Johannes Gutenberg University, Duesbergweg 10-14, 55122, Mainz, Germany
- Rowland Institute, Harvard University, 100 Edwin H. Land Boulevard, Cambridge, MA, 02142, USA
| | - John Freudenthal
- Hinds Instruments Inc., 7245 NE Evergreen Parkway, Hillsboro, OR, 97124, USA
| | - Antti-Pekka M Reponen
- Rowland Institute, Harvard University, 100 Edwin H. Land Boulevard, Cambridge, MA, 02142, USA
| | - Zachary A VanOrman
- Rowland Institute, Harvard University, 100 Edwin H. Land Boulevard, Cambridge, MA, 02142, USA
| | - Sascha Feldmann
- Rowland Institute, Harvard University, 100 Edwin H. Land Boulevard, Cambridge, MA, 02142, USA
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Ikeshita M, He H, Kitahara M, Imai Y, Tsuno T. External environment sensitive circularly polarized luminescence properties of a chiral boron difluoride complex. RSC Adv 2022; 12:34790-34796. [PMID: 36540273 PMCID: PMC9724127 DOI: 10.1039/d2ra07386b] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Accepted: 11/28/2022] [Indexed: 08/23/2024] Open
Abstract
A chiral Schiff-base boron difluoride complex bearing a diethylamino group was synthesized. Its photophysical properties were investigated and compared with those of its non-substituted analogue. The complex was found to exhibit solvatofluorochromism with bluish-white emission in moderately polar solvents and intense blue emission in nonpolar solvent. Circularly polarized luminescence (CPL) properties were also examined and it was found that the absolute value of the luminescence dissymmetry factor (g lum) increases significantly in the KBr-dispersed pellet state compared to the solution state. Notably, CPL intensity of the complex enhanced approximately three times upon addition of CH3SO3H in CH2Cl2. Density functional theory (DFT) calculations were conducted to further understand the photophysical properties.
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Affiliation(s)
- Masahiro Ikeshita
- Department of Applied Molecular Chemistry, College of Industrial Technology, Nihon University Narashino Chiba 275-8575 Japan
| | - Hongxi He
- Department of Applied Molecular Chemistry, College of Industrial Technology, Nihon University Narashino Chiba 275-8575 Japan
| | - Maho Kitahara
- Department of Applied Chemistry, Faculty of Science and Engineering, Kindai University 3-4-1 Kowakae Higashi-Osaka Osaka 577-8502 Japan
| | - Yoshitane Imai
- Department of Applied Chemistry, Faculty of Science and Engineering, Kindai University 3-4-1 Kowakae Higashi-Osaka Osaka 577-8502 Japan
| | - Takashi Tsuno
- Department of Applied Molecular Chemistry, College of Industrial Technology, Nihon University Narashino Chiba 275-8575 Japan
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Morikubo J, Tsubomura T. Circularly Polarized Luminescence of Cyclometalated Platinum(II) Complex Excimers: Large Difference between Isomers. Inorg Chem 2022; 61:17154-17165. [PMID: 36260480 DOI: 10.1021/acs.inorgchem.2c02662] [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
A series of platinum(II) complexes bearing a chiral β-diketonato ligand and a cyclometalated ligand have been prepared. The platinum(II) complexes, (SP-4-3)-[Pt(ppy)(D-tac)] (ppy = 2-phenylpyridine, D-tac = 3-trifluoroacetyl-(D)-camphor), (SP-4-4)-[Pt(ppy)(D-tac)], (SP-4-3)-[Pt(ppy)(D-pbc)] (D-pbc = 3-perfluorobutyryl-(D)-camphor), and (SP-4-4)-[Pt(ppy)(D-pbc)], and their enantiomers were isolated and characterized by elemental analysis, NMR, and X-ray structural analysis. Photoisomerization between SP-4-3 (trans) and SP-4-4 (cis) isomers was observed. Green emission due to the monomer was observed in diluted solutions for all complexes. Higher quantum yields and longer lifetimes of green emission were observed in nonpolar solvents compared to polar solvents. The two geometrical isomers had surprisingly different excimer formation efficiencies. For the trans isomers, orange emission due to the excimers was observed in nonpolar solvents at high concentrations, whereas negligible intensities of the excimer emission were observed for the cis isomers. The formation of the excimers was evaluated by emission decay and time-resolved emission spectra. For the trans isomers, the green emission due to the monomer showed negligible CPL signals, but the orange emission gave pronounced CPL signals. The dissymmetry factors, g-values, of the excimer CPL (glum = 0.002) were enhanced over those of the circular dichroism (gabs = 0.0002, glum/gabs = 10). The intensities of the emission and the CPL of the excimer under oxygen were very small, although those under an argon atmosphere were very strong. Therefore, the emission color of the trans-isomers was changed from green to orange by deoxygenation.
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Affiliation(s)
- Jun Morikubo
- Department of Materials and Life Science, Seikei University, Musashino, Tokyo1808633, Japan
| | - Taro Tsubomura
- Department of Materials and Life Science, Seikei University, Musashino, Tokyo1808633, Japan
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Ikeshita M, Yamamoto T, Watanabe S, Kitahara M, Imai Y, Tsuno T. Circularly Polarized Luminescence of Chiral Platinum(II) Complexes with Tetradentate Salen Ligands. CHEM LETT 2022. [DOI: 10.1246/cl.220224] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Masahiro Ikeshita
- Department of Applied Molecular Chemistry, College of Industrial Technology, Nihon University, Narashino, Chiba 275-8575, Japan
| | - Takuho Yamamoto
- Department of Applied Molecular Chemistry, College of Industrial Technology, Nihon University, Narashino, Chiba 275-8575, Japan
| | - Shinya Watanabe
- Department of Applied Molecular Chemistry, College of Industrial Technology, Nihon University, Narashino, Chiba 275-8575, Japan
| | - Maho Kitahara
- Department of Applied Chemistry, Faculty of Science and Engineering, Kindai University, 3-4-1 Kowakae, Higashi-Osaka, Osaka 577-8502, Japan
| | - Yoshitane Imai
- Department of Applied Chemistry, Faculty of Science and Engineering, Kindai University, 3-4-1 Kowakae, Higashi-Osaka, Osaka 577-8502, Japan
| | - Takashi Tsuno
- Department of Applied Molecular Chemistry, College of Industrial Technology, Nihon University, Narashino, Chiba 275-8575, Japan
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