1
|
Narita H, Min H, Kubo N, Hattori I, Yasuda T, Yamaguchi S. Bis-Ortho-Donor-Modification of Boracyclic π-Electron Systems beyond Steric Protection to Produce Thermally Activated Delayed Fluorescence Materials. Angew Chem Int Ed Engl 2024; 63:e202405412. [PMID: 38714489 DOI: 10.1002/anie.202405412] [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: 03/19/2024] [Revised: 05/02/2024] [Accepted: 05/02/2024] [Indexed: 05/10/2024]
Abstract
Polycyclic π-conjugated compounds that contain tricoordinate boron atoms at their periphery represent an attractive class of materials with electron-accepting character. Their molecular design generally requires the introduction of a bulky aryl group onto the boron atom, where it provides predominantly kinetic stabilization. The addition of extra functionality to the aryl group on the boron atom can be expected to further expand the potential utility of this class of materials. Herein, we report the synthesis of a series of boracyclic π-conjugated molecules with firm ortho B⋅⋅⋅N nonbonding interactions by introducing N-containing electron-donors at the ortho-positions of the aryl group on the boron atom. X-ray crystallographic analysis revealed that the combination of a planar boracyclic π-skeleton with only sp2 carbons and a strong electron-donating phenothiazine moiety results in a particularly short B⋅⋅⋅N distance. Theoretical study provided insights into the inherent nature of the B⋅⋅⋅N interaction. Owing to their donor-acceptor (D-A) structures, these molecules exhibit substantially red-shifted fluorescence in solution, albeit that the fluorescence quantum yields (ΦF) are low. In contrast, when incorporated into films, these compounds exhibit thermally activated delayed fluorescence (TADF) with improved ΦF values. Organic light-emitting diodes (OLEDs) fabricated using the ortho-donor-substituted derivatives exhibit orange-red electroluminescence.
Collapse
Affiliation(s)
- Hiroki Narita
- Department of Chemistry, Graduate School of Science, Research Center for Materials Science (RCMS), Integrated Research Consortium on Chemical Sciences (IRCCS), Nagoya University, Furo, Chikusa, Nagoya, 464-8602, Japan
| | - Hyukgi Min
- Department of Applied Chemistry, Graduate School of Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan
- Institute for Advanced Study, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan
| | - Nanami Kubo
- Department of Applied Chemistry, Graduate School of Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan
- Institute for Advanced Study, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan
| | - Izumi Hattori
- Department of Chemistry, Graduate School of Science, Research Center for Materials Science (RCMS), Integrated Research Consortium on Chemical Sciences (IRCCS), Nagoya University, Furo, Chikusa, Nagoya, 464-8602, Japan
| | - Takuma Yasuda
- Department of Applied Chemistry, Graduate School of Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan
- Institute for Advanced Study, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan
| | - Shigehiro Yamaguchi
- Department of Chemistry, Graduate School of Science, Research Center for Materials Science (RCMS), Integrated Research Consortium on Chemical Sciences (IRCCS), Nagoya University, Furo, Chikusa, Nagoya, 464-8602, Japan
- Institute of Transformative Bio-Molecules (WPI-ITbM), Nagoya University, Furo, Chikusa, Nagoya, 464-8601, Japan
| |
Collapse
|
2
|
Abstract
X-ray crystallography is an invaluable tool in design and development of organometallic catalysis, but application typically requires species to display sufficiently high solution concentrations and lifetimes for single crystalline samples to be obtained. In crystallo organometallic chemistry relies on chemical reactions that proceed within the single-crystal environment to access crystalline samples of reactive organometallic fragments that are unavailable by alternate means. This highlight describes approaches to in crystallo organometallic chemistry including (a) solid-gas reactions between transition metal complexes in molecular crystals and diffusing small molecules, (b) reactions of organometallic complexes within the extended lattices of metal-organic frameworks (MOFs), and (c) intracrystalline photochemical transformations to generate reactive organometallic fragments. Application of these methods has enabled characterization of catalytically important transient species, including σ-alkane adducts of transition metals, metal alkyl intermediates implicated in metal-catalyzed carbonylations, and reactive M-L multiply bonded species involved in C-H functionalization chemistry. Opportunities and challenges for in crystallo organometallic chemistry are discussed.
Collapse
Affiliation(s)
- Kaleb A Reid
- Department of Chemistry, Texas A&M University, 3255 TAMU, College Station, TX 77843, USA.
| | - David C Powers
- Department of Chemistry, Texas A&M University, 3255 TAMU, College Station, TX 77843, USA.
| |
Collapse
|
3
|
Bodach A, Nöthling N, Felderhoff M. Activation of Molecular Hydrogen by Inter‐ and Intramolecular Al−N Lewis Pairs. Eur J Inorg Chem 2021. [DOI: 10.1002/ejic.202001152] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
| | - Nils Nöthling
- Max-Planck-Institut für Kohlenforschung Kaiser-Wilhelm-Platz 1
| | | |
Collapse
|
4
|
Bodach A, Bernert T, Fischer M, Ley MB, Weidenthaler C. Polymorphism of dimethylaminoborane N(CH 3) 2-BH 2. ACTA CRYSTALLOGRAPHICA SECTION B, STRUCTURAL SCIENCE, CRYSTAL ENGINEERING AND MATERIALS 2021; 77:299-306. [PMID: 33843738 PMCID: PMC8040097 DOI: 10.1107/s2052520621001979] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Accepted: 02/19/2021] [Indexed: 06/12/2023]
Abstract
Dehydrocoupling of the adduct of dimethylamine and borane, NH(CH3)2-BH3 leads to dimethylaminoborane with formal composition N(CH3)2-BH2. The structure of this product depends on the conditions of the synthesis; it may crystallize either as a dimer in a triclinic space group forming a four-membered ring [N(CH3)2-BH2]2 or as a trimer forming a six-membered ring [N(CH3)2-BH2]3 in an orthorhombic space group. Due to the denser packing, the six-membered ring in the trimer structure should be energetically more stable than the four-membered ring. The triclinic structure is stable at low temperatures. Heating the triclinic phase above 290 K leads to a second-order phase transition to a new monoclinic polymorph. While the crystal structures of the triclinic and orthorhombic phases were already known in the literature, the monoclinic crystal structure was determined from powder diffraction data in this study. Monoclinic dimethylaminoborane crystallizes in space group C2/m with the boron and nitrogen atoms located on the mirror plane, Wyckoff position 4i, while the carbon and hydrogen atoms are on the general position 8j.
Collapse
Affiliation(s)
- Alexander Bodach
- Heterogeneous Catalysis, Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, Mülheim an der Ruhr, 45470, Germany
| | - Thomas Bernert
- Heterogeneous Catalysis, Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, Mülheim an der Ruhr, 45470, Germany
| | - Michael Fischer
- Crystallography/Geosciences, University Bremen, Klagenfurter Str., Bremen, 28359, Germany
- MAPEX Center for Materials and Processes, University of Bremen, Bremen, 28359, Germany
| | - Morten Brix Ley
- Heterogeneous Catalysis, Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, Mülheim an der Ruhr, 45470, Germany
| | - Claudia Weidenthaler
- Heterogeneous Catalysis, Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, Mülheim an der Ruhr, 45470, Germany
| |
Collapse
|