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Yoshida J, Yamazaki K, Tateyama K, Yuge H, Sato H. Chiroptical switching behavior of heteroleptic ruthenium complexes bearing acetylacetonato and tropolonato ligands. Dalton Trans 2021; 50:14611-14617. [PMID: 34605516 DOI: 10.1039/d1dt02592a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Four types of tris-chelate ruthenium complexes bearing acetylacetonato (acac) and tropolonato (trop) ligands were synthesized and optically resolved into Δ and Λ isomers: [Ru(acac)3] (Ru-0), [Ru(acac)2(trop)] (Ru-1), [Ru(acac)(trop)2] (Ru-2), and [Ru(trop)3] (Ru-3). Chiral HPLC chromatograms, electronic circular dichroism (ECD), and vibrational circular dichroism (VCD) of the four ruthenium complexes were systematically investigated. As a result, the absolute configurations of the newly prepared enantiomeric complexes Ru-2 and Ru-3 were determined. For the case of Ru-2, its absolute configuration was also confirmed by single crystal X-ray diffraction analysis. The ECD changes upon chemical oxidation were further investigated for the four complexes. An ECD change in enantiomeric Ru-1 was observed upon oxidation, but the oxidized species soon returned to the neutral state within a few minutes. Enantiomers of Ru-3 also showed explicit ECD changes upon oxidation. Further, the lifetime of the oxidized state was the longest among the four investigated complexes, whereas they racemized in solution at room temperature. In contrast, the enantiomers of heteroleptic complexes (Ru-1 and Ru-2) concurrently exhibited ECD changes, relatively long lifetime of the oxidized state, and nil or quite slow racemization behavior. The coexistence of acac and trop ligands was key to making the competing factors compatible in the resultant ruthenium complexes.
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Affiliation(s)
- Jun Yoshida
- Department of Chemistry, College of Humanities & Sciences, Nihon University, 3-25-40 Sakurajosui, Setagaya-ku, Tokyo 156-8550, Japan.
| | - Kana Yamazaki
- Department of Chemistry, School of Science, Kitasato University, 1-15-1 Kitasato Minami-ku, Sagamihara, 252-0373, Japan
| | - Kazunori Tateyama
- Department of Chemistry, School of Science, Kitasato University, 1-15-1 Kitasato Minami-ku, Sagamihara, 252-0373, Japan
| | - Hidetaka Yuge
- Department of Chemistry, School of Science, Kitasato University, 1-15-1 Kitasato Minami-ku, Sagamihara, 252-0373, Japan
| | - Hisako Sato
- Graduate School of Science and Engineering, Ehime University, 2-5 Bunkyo-chou, Matsuyama, Ehime 790-8577, Japan
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Watanabe G, Watanabe H, Suzuki K, Yuge H, Yoshida S, Mandai T, Yoneda S, Sato H, Hara M, Yoshida J. Visualizing the helical stacking of octahedral metallomesogens with a chiral core. Chem Commun (Camb) 2020; 56:12134-12137. [PMID: 32966410 DOI: 10.1039/d0cc05930g] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A combination of grazing-incidence X-ray diffraction and molecular dynamics simulation studies led to the visualization of the stacking structure of a helical columnar liquid crystal formed by enantiopure octahedral metallomesogens with ΔΛ chirality. The helical structure was elucidated as a hybrid of two major proposed structures.
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Affiliation(s)
- Go Watanabe
- Department of Physics, School of Science, Kitasato University, 1-15-1, Kitasato, Minami-ku, Sagamihara 252-0373, Japan.
| | - Hideyo Watanabe
- Department of Chemistry, School of Science, Kitasato University, 1-15-1, Kitasato, Minami-ku, Sagamihara 252-0373, Japan.
| | - Kota Suzuki
- Department of Chemistry, School of Science, Kitasato University, 1-15-1, Kitasato, Minami-ku, Sagamihara 252-0373, Japan.
| | - Hidetaka Yuge
- Department of Chemistry, School of Science, Kitasato University, 1-15-1, Kitasato, Minami-ku, Sagamihara 252-0373, Japan.
| | - Shintaro Yoshida
- Department of Physics, School of Science, Kitasato University, 1-15-1, Kitasato, Minami-ku, Sagamihara 252-0373, Japan.
| | - Takuyoshi Mandai
- Department of Physics, School of Science, Kitasato University, 1-15-1, Kitasato, Minami-ku, Sagamihara 252-0373, Japan.
| | - Shigetaka Yoneda
- Department of Physics, School of Science, Kitasato University, 1-15-1, Kitasato, Minami-ku, Sagamihara 252-0373, Japan.
| | - Hisako Sato
- Department of Chemistry, Graduate School of Science and Engineering, Ehime University, 2-5, Bunkyo-cho, Matsuyama 790-8577, Japan
| | - Mitsuo Hara
- Department of Molecular and Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan.
| | - Jun Yoshida
- Department of Chemistry, School of Science, Kitasato University, 1-15-1, Kitasato, Minami-ku, Sagamihara 252-0373, Japan.
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