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Nandi RP, Chandra B, Ghosh S, Sarma SP, Geremia S, Hickey N, Thilagar P. Pyrrole βC-B-N Fused Porphyrins: Molecular Structures and Opto-Electrochemical Studies. Chemistry 2024; 30:e202304219. [PMID: 38155424 DOI: 10.1002/chem.202304219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Accepted: 12/28/2023] [Indexed: 12/30/2023]
Abstract
Herein, we report the design, synthesis, structure, and electrochemical study of doubly βC-B-N fused Ni(II) porphyrins (1-trans, 1-cis, 2-trans, and 2-cis). These compounds have been synthesized from A2B2 type dipyridyl Ni(II) porphyrins (Ar=Ph for 1 a; Ar=C6F5 for 2 a) via Lewis base-directed electrophilic aromatic borylation reactions. The solution state structures of these compounds have been established using 1H NMR, 11B NMR, 1H-1H COSY, 1H-13C HSQC, and 19F-13C HSQC NMR techniques. Single crystal X-ray analysis have revealed that 1-trans, 1-cis, and 2-trans adopt ruffled conformations, with alternate meso-carbons on the opposite sides of the mean porphyrin plane. The Soret bands in the absorption spectra of the B-N fused molecules are ~40 nm redshifted compared to unfused Ni(II) porphyrin precursors. The B-N fusion have diminished the redox potential of fused porphyrins. Although 1-trans and 1-cis, show four oxidation processes, 2-trans and 2-cis show only three oxidation processes. DFT studies have revealed that the tetrahedral geometry of the boron has induced a twist in the π-conjugation, which destabilizes the HOMO and stabilizes the LUMO in 1-trans, 1-cis, 2-trans, and 2-cis.
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Affiliation(s)
- Rajendra Prasad Nandi
- Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore, 560012, INDIA
| | - Brijesh Chandra
- Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore, 560012, INDIA
| | - Subhajit Ghosh
- Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore, 560012, INDIA
| | - Siddhartha P Sarma
- Molecular Biophysics Unit, Division of Biological Sciences, Indian Institute of Science, Bangalore, 560012, INDIA
| | - Silvano Geremia
- Department of Chemical and Pharmaceutical Sciences, University of Trieste, via L. Giorgieri 1, 34127, Trieste, ITALY
| | - Neal Hickey
- Department of Chemical and Pharmaceutical Sciences, University of Trieste, via L. Giorgieri 1, 34127, Trieste, ITALY
| | - Pakkirisamy Thilagar
- Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore, 560012, INDIA
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Full J, Wildervanck MJ, Dillmann C, Panchal SP, Volland D, Full F, Meerholz K, Nowak-Król A. Impact of Truncation on Optoelectronic Properties of Azaborole Helicenes. Chemistry 2023:e202302808. [PMID: 37651165 DOI: 10.1002/chem.202302808] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 08/31/2023] [Accepted: 08/31/2023] [Indexed: 09/01/2023]
Abstract
Herein, we report configurationally stable singly-truncated (ST) and structurally flexible doubly-truncated (DT) helically chiral compounds derived from azabora[7]helicenes by a hypothetical removal of a single or two C=C double bonds. The singly-truncated constitutional isomers were synthesized from either benzoisoquinoline (BIQ) or phenantherene building blocks and the corresponding biaryls in excellent yields to give azabora[5]helicenes with a pendant phenyl ring at a sterically hindered position. These systems highlight the electronic impact of the nitrogen donor substitution position. The compounds with a disrupted BIQ moiety (STN) possess remarkable photoluminescence quantum yields of up to 0.53 in the solid state and a blue emission in solution with dissymmetry factors of up to ca. 3×10-3 . Upon cooling to 79 K all compounds exhibit phosphorescence with lifetimes of up to ca. 0.5 s. A methyl complex of azabora[7]helicene showing excellent configurational stability was used as a chiral inducer embedded in an emissive polymer (F8BT) to produce circularly polarized organic light emitting diodes with an electroluminescence dissymmetry factor gEL of up to 0.54.
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Affiliation(s)
- Julian Full
- Institut für Anorganische Chemie and Institute for Sustainable Chemistry & Catalysis with Boron, Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
- Institut für Organische Chemie and Center for Nanosystems Chemistry, Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Martijn J Wildervanck
- Institut für Anorganische Chemie and Institute for Sustainable Chemistry & Catalysis with Boron, Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
- Institut für Organische Chemie and Center for Nanosystems Chemistry, Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Claudia Dillmann
- Department of Chemistry, University of Cologne, Greinstr. 4-6, 50939, Köln, Germany
| | - Santosh P Panchal
- Institut für Anorganische Chemie and Institute for Sustainable Chemistry & Catalysis with Boron, Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
- Institut für Organische Chemie and Center for Nanosystems Chemistry, Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Daniel Volland
- Institut für Anorganische Chemie and Institute for Sustainable Chemistry & Catalysis with Boron, Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
- Institut für Organische Chemie and Center for Nanosystems Chemistry, Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Felix Full
- Institut für Anorganische Chemie and Institute for Sustainable Chemistry & Catalysis with Boron, Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
- Institut für Organische Chemie and Center for Nanosystems Chemistry, Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Klaus Meerholz
- Department of Chemistry, University of Cologne, Greinstr. 4-6, 50939, Köln, Germany
| | - Agnieszka Nowak-Król
- Institut für Anorganische Chemie and Institute for Sustainable Chemistry & Catalysis with Boron, Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
- Institut für Organische Chemie and Center for Nanosystems Chemistry, Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
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Kitamoto Y, Oda K, Kita H, Hattori T, Oi S. Synthesis of Azadioxa-Planar Triphenylboranes Bridged by Aryl- and Alkylimino Groups and Their Photophysical Properties. J Org Chem 2023; 88:5852-5860. [PMID: 37083363 DOI: 10.1021/acs.joc.3c00275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/22/2023]
Abstract
Heteroatom-bridged planar triphenylboranes, in which the three phenyl groups are bridged at the ortho positions by heteroatoms, are attracting growing attention as one of the heteroatom-containing π-conjugated molecules. Herein, we developed the synthetic method of planar triphenylboranes bridged by two oxygen atoms and one nitrogen atom, and the substituent on the nitrogen atom is derived into various aryl and alkyl groups. A key intermediate bearing an imino group (-NH-) was synthesized from a bis-triflate precursor bridged by two oxo groups via a nucleophilic aromatic substitution reaction of benzyl amine and following debenzylation. The X-ray crystallographic analysis revealed that the compound exhibits a planar molecular structure which can form a one-dimensionally π-stacked structure. The photophysical and density functional theory studies revealed that their highest occupied molecular orbitals and lowest unoccupied molecular orbitals (LUMOs) are originated from the triphenylborane moiety, while introducing strong electron-withdrawing groups such as the 4-cyanophenyl group on the nitrogen atom can induce the localization of the LUMO at the aryl groups instead of the triphenylborane moiety.
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Affiliation(s)
- Yuichi Kitamoto
- Department of Biomolecular Engineering, Graduate School of Engineering, Tohoku University, 6-6-11 Aramaki-Aoba, Aoba-ku, Sendai 980-8579, Japan
| | - Kazuma Oda
- Advanced Core Technology Center, Technology Development Headquarters, KONICA MINOLTA, INC., 2970 Ishikawa-machi, Hachioji-shi, Tokyo 192-8505, Japan
| | - Hiroshi Kita
- Advanced Core Technology Center, Technology Development Headquarters, KONICA MINOLTA, INC., 2970 Ishikawa-machi, Hachioji-shi, Tokyo 192-8505, Japan
| | - Tetsutaro Hattori
- Department of Biomolecular Engineering, Graduate School of Engineering, Tohoku University, 6-6-11 Aramaki-Aoba, Aoba-ku, Sendai 980-8579, Japan
| | - Shuichi Oi
- Department of Applied Chemistry, Graduate School of Engineering, Tohoku University, 6-6-11 Aramaki-Aoba, Aoba-ku, Sendai 980-8579, Japan
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Double boron-embedded multiresonant thermally activated delayed fluorescent materials for organic light-emitting diodes. Commun Chem 2022; 5:149. [PMID: 36698018 PMCID: PMC9814903 DOI: 10.1038/s42004-022-00766-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2022] [Accepted: 10/25/2022] [Indexed: 11/12/2022] Open
Abstract
The subclass of multi resonant thermally activated delayed fluorescent emitters (MR-TADF) containing boron atoms has garnered significant attention in the field of organic light emitting diode (OLED) research. Among boron-based MR-TADF emitters, double boron-embedded MR-TADF (DB-MR-TADF) emitters show excellent electroluminescence performances with high photoluminescence quantum yields, narrow band emission, and beneficially small singlet-triplet energy levels in all the full-color gamut regions. This article reviews recent progress in DB-MR-TADF emitters, with particular attention to molecular design concepts, synthetic routes, optoelectronic properties, and OLED performance, giving future prospects for real-world applications.
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