1
|
Stoy A, Arrowsmith M, Eyßelein M, Dellermann T, Mies J, Radacki K, Kupfer T, Braunschweig H. NHC-Stabilized 1,2-Dihalodiborenes: Synthesis, Characterization, and Reactivity Toward Elemental Chalcogens. Inorg Chem 2021; 60:12625-12633. [PMID: 34042444 DOI: 10.1021/acs.inorgchem.1c01169] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The 2-fold reduction of B2X4(NHC)2 (X = Cl, Br, I; NHC = (un)saturated N-heterocyclic carbene) yields the corresponding green-colored 1,2-dihalodiborenes B2X2(NHC)2, the 11B NMR resonances of which are strongly upfield-shifted upon descending the halide group. The diborenes crystallize as the trans isomers, with relatively short B═B double bonds (1.513(9) to 1.568(4) Å). Cyclic voltammetric experiments with these diborenes reveal reversible one-electron oxidation processes to the corresponding diboron radical cation (E1/2 = -1.16 to -1.50 V); the reducing power of B2X2(NHC)2 increasing with the electronegativity of the halide and for the less π-accepting unsaturated NHCs. The main UV-vis absorption (393-463 nm), which corresponds mainly to a highest occupied molecular orbital (HOMO) → lowest unoccupied molecular orbital (LUMO) transition, undergoes a blueshift upon descending the halide group and shows some dependence on the stereoelectronics of the NHC ligands. Computational analyses show that the HOMO of B2X2(NHC)2 is mostly localized on the B═B π bond, with the contribution from halide p orbitals decreasing down the group, and the saturated NHCs affording some π-bonding delocalization over the B-CNHC bonds. The calculated HOMO and LUMO energies decrease upon descending the halide group, while the HOMO-LUMO gap also decreases, correlating well with the cyclovoltammetry and UV-vis data. The reactions of B2Br2(NHC)2 with elemental sulfur and red selenium lead to the formation of the corresponding diborathiiranes and seleniranes, respectively, which were characterized by NMR and UV-vis spectroscopy, cyclic voltammetry, and X-ray diffraction analyses. In one case, an additional one-electron oxidation yields a unique cyclic B2Se radical cation. Computational analyses show that the localization of the HOMO and HOMO - 1 of the diboraseleniranes is inverted compared to the diborathiiranes.
Collapse
Affiliation(s)
- Andreas Stoy
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.,Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Merle Arrowsmith
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.,Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Maximilian Eyßelein
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.,Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Theresa Dellermann
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.,Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Jan Mies
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.,Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Krzysztof Radacki
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.,Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Thomas Kupfer
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.,Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Holger Braunschweig
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.,Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| |
Collapse
|
2
|
Englert L, Stoy A, Arrowsmith M, Muessig JH, Thaler M, Deißenberger A, Häfner A, Böhnke J, Hupp F, Seufert J, Mies J, Damme A, Dellermann T, Hammond K, Kupfer T, Radacki K, Thiess T, Braunschweig H. Stable Lewis Base Adducts of Tetrahalodiboranes: Synthetic Methods and Structural Diversity. Chemistry 2019; 25:8612-8622. [DOI: 10.1002/chem.201901437] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Indexed: 02/02/2023]
Affiliation(s)
- Lukas Englert
- Institute for Inorganic Chemistry and theInstitute for Sustainable Chemistry & Catalysis with BoronJulius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
| | - Andreas Stoy
- Institute for Inorganic Chemistry and theInstitute for Sustainable Chemistry & Catalysis with BoronJulius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
| | - Merle Arrowsmith
- Institute for Inorganic Chemistry and theInstitute for Sustainable Chemistry & Catalysis with BoronJulius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
| | - Jonas H. Muessig
- Institute for Inorganic Chemistry and theInstitute for Sustainable Chemistry & Catalysis with BoronJulius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
| | - Melanie Thaler
- Institute for Inorganic Chemistry and theInstitute for Sustainable Chemistry & Catalysis with BoronJulius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
| | - Andrea Deißenberger
- Institute for Inorganic Chemistry and theInstitute for Sustainable Chemistry & Catalysis with BoronJulius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
| | - Alena Häfner
- Institute for Inorganic Chemistry and theInstitute for Sustainable Chemistry & Catalysis with BoronJulius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
| | - Julian Böhnke
- Institute for Inorganic Chemistry and theInstitute for Sustainable Chemistry & Catalysis with BoronJulius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
| | - Florian Hupp
- Institute for Inorganic Chemistry and theInstitute for Sustainable Chemistry & Catalysis with BoronJulius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
| | - Jens Seufert
- Institute for Inorganic Chemistry and theInstitute for Sustainable Chemistry & Catalysis with BoronJulius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
| | - Jan Mies
- Institute for Inorganic Chemistry and theInstitute for Sustainable Chemistry & Catalysis with BoronJulius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
| | - Alexander Damme
- Institute for Inorganic Chemistry and theInstitute for Sustainable Chemistry & Catalysis with BoronJulius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
| | - Theresa Dellermann
- Institute for Inorganic Chemistry and theInstitute for Sustainable Chemistry & Catalysis with BoronJulius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
| | - Kai Hammond
- Institute for Inorganic Chemistry and theInstitute for Sustainable Chemistry & Catalysis with BoronJulius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
| | - Thomas Kupfer
- Institute for Inorganic Chemistry and theInstitute for Sustainable Chemistry & Catalysis with BoronJulius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
| | - Krzysztof Radacki
- Institute for Inorganic Chemistry and theInstitute for Sustainable Chemistry & Catalysis with BoronJulius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
| | - Torsten Thiess
- Institute for Inorganic Chemistry and theInstitute for Sustainable Chemistry & Catalysis with BoronJulius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
| | - Holger Braunschweig
- Institute for Inorganic Chemistry and theInstitute for Sustainable Chemistry & Catalysis with BoronJulius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
| |
Collapse
|
3
|
Schuster JK, Roy DK, Lenczyk C, Mies J, Braunschweig H. New Outcomes of Beryllium Chemistry: Lewis Base Adducts for Salt Elimination Reactions. Inorg Chem 2019; 58:2652-2658. [DOI: 10.1021/acs.inorgchem.8b03263] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Julia K. Schuster
- Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
- Institute for Sustainable Chemistry and Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Dipak Kumar Roy
- Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
- Institute for Sustainable Chemistry and Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Carsten Lenczyk
- Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
- Institute for Sustainable Chemistry and Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Jan Mies
- Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
- Institute for Sustainable Chemistry and Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Holger Braunschweig
- Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
- Institute for Sustainable Chemistry and Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| |
Collapse
|
4
|
Braunschweig H, Dellermann T, Dewhurst RD, Hupp B, Kramer T, Mattock JD, Mies J, Phukan AK, Steffen A, Vargas A. Strongly Phosphorescent Transition Metal π-Complexes of Boron–Boron Triple Bonds. J Am Chem Soc 2017; 139:4887-4893. [DOI: 10.1021/jacs.7b00766] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Holger Braunschweig
- Institute
for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
- Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Theresa Dellermann
- Institute
for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
- Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Rian D. Dewhurst
- Institute
for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
- Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Benjamin Hupp
- Institute
for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Thomas Kramer
- Institute
for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - James D. Mattock
- Department
of Chemistry, School of Life Sciences, University of Sussex, Brighton BN1 9QJ, Sussex, United Kingdom
| | - Jan Mies
- Institute
for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Ashwini K. Phukan
- Department
of Chemical Sciences, Tezpur University Napaam, 784028 Assam, India
| | - Andreas Steffen
- Institute
for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Alfredo Vargas
- Department
of Chemistry, School of Life Sciences, University of Sussex, Brighton BN1 9QJ, Sussex, United Kingdom
| |
Collapse
|
5
|
Arrowsmith M, Böhnke J, Braunschweig H, Deißenberger A, Dewhurst RD, Ewing WC, Hörl C, Mies J, Muessig JH. Simple solution-phase syntheses of tetrahalodiboranes(4) and their labile dimethylsulfide adducts. Chem Commun (Camb) 2017; 53:8265-8267. [DOI: 10.1039/c7cc03148c] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Convenient solution-phase syntheses of tetrahalodiboranes(4) and the dimethylsulfide adducts B2Cl4(SMe2)2 and B2Br4(SMe2)2 are presented.
Collapse
Affiliation(s)
- Merle Arrowsmith
- Institute for Inorganic Chemistry
- Julius-Maximilians-Universität Würzburg
- 97074 Würzburg
- Germany
- Institute for Sustainable Chemistry & Catalysis with Boron
| | - Julian Böhnke
- Institute for Inorganic Chemistry
- Julius-Maximilians-Universität Würzburg
- 97074 Würzburg
- Germany
- Institute for Sustainable Chemistry & Catalysis with Boron
| | - Holger Braunschweig
- Institute for Inorganic Chemistry
- Julius-Maximilians-Universität Würzburg
- 97074 Würzburg
- Germany
- Institute for Sustainable Chemistry & Catalysis with Boron
| | - Andrea Deißenberger
- Institute for Inorganic Chemistry
- Julius-Maximilians-Universität Würzburg
- 97074 Würzburg
- Germany
- Institute for Sustainable Chemistry & Catalysis with Boron
| | - Rian D. Dewhurst
- Institute for Inorganic Chemistry
- Julius-Maximilians-Universität Würzburg
- 97074 Würzburg
- Germany
- Institute for Sustainable Chemistry & Catalysis with Boron
| | - William C. Ewing
- Institute for Inorganic Chemistry
- Julius-Maximilians-Universität Würzburg
- 97074 Würzburg
- Germany
| | - Christian Hörl
- Institute for Inorganic Chemistry
- Julius-Maximilians-Universität Würzburg
- 97074 Würzburg
- Germany
| | - Jan Mies
- Institute for Inorganic Chemistry
- Julius-Maximilians-Universität Würzburg
- 97074 Würzburg
- Germany
| | - Jonas H. Muessig
- Institute for Inorganic Chemistry
- Julius-Maximilians-Universität Würzburg
- 97074 Würzburg
- Germany
- Institute for Sustainable Chemistry & Catalysis with Boron
| |
Collapse
|
6
|
Braunschweig H, Demeshko S, Ewing WC, Krummenacher I, Macha BB, Mattock JD, Meyer F, Mies J, Schäfer M, Vargas A. A Binuclear 1,1′-Bis(boratabenzene) Complex: Unprecedented Intramolecular Metal-Metal Communication through a B−B Bond. Angew Chem Int Ed Engl 2016; 55:7708-11. [DOI: 10.1002/anie.201603437] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Indexed: 11/11/2022]
Affiliation(s)
- Holger Braunschweig
- Institut für Anorganische Chemie; Julius-Maximilians-Universität Würzburg; Am Hubland 97074 Würzburg Germany
| | - Serhiy Demeshko
- Institut für Anorganische Chemie; Georg-August-Universität Göttingen; Tammannstrasse 4 37077 Göttingen Germany
| | - William C. Ewing
- Institut für Anorganische Chemie; Julius-Maximilians-Universität Würzburg; Am Hubland 97074 Würzburg Germany
| | - Ivo Krummenacher
- Institut für Anorganische Chemie; Julius-Maximilians-Universität Würzburg; Am Hubland 97074 Würzburg Germany
| | - Bret B. Macha
- Institut für Anorganische Chemie; Julius-Maximilians-Universität Würzburg; Am Hubland 97074 Würzburg Germany
| | - James D. Mattock
- Department of Chemistry, School of Life Sciences; University of Sussex; Brighton BN1 9QJ Sussex UK
| | - Franc Meyer
- Institut für Anorganische Chemie; Georg-August-Universität Göttingen; Tammannstrasse 4 37077 Göttingen Germany
| | - Jan Mies
- Institut für Anorganische Chemie; Julius-Maximilians-Universität Würzburg; Am Hubland 97074 Würzburg Germany
| | - Marius Schäfer
- Institut für Anorganische Chemie; Julius-Maximilians-Universität Würzburg; Am Hubland 97074 Würzburg Germany
| | - Alfredo Vargas
- Department of Chemistry, School of Life Sciences; University of Sussex; Brighton BN1 9QJ Sussex UK
| |
Collapse
|
7
|
Braunschweig H, Demeshko S, Ewing WC, Krummenacher I, Macha BB, Mattock JD, Meyer F, Mies J, Schäfer M, Vargas A. Ein zweikerniger 1,1′-Bis(boratabenzol)-Komplex: beispiellose intramolekulare Metall-Metall-Kommunikation durch eine B-B-Bindung. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201603437] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Holger Braunschweig
- Institut für Anorganische Chemie; Julius-Maximilians-Universität Würzburg; Am Hubland 97074 Würzburg Deutschland
| | - Serhiy Demeshko
- Institut für Anorganische Chemie; Georg-August-Universität Göttingen; Tammannstraße 4 37077 Göttingen Deutschland
| | - William C. Ewing
- Institut für Anorganische Chemie; Julius-Maximilians-Universität Würzburg; Am Hubland 97074 Würzburg Deutschland
| | - Ivo Krummenacher
- Institut für Anorganische Chemie; Julius-Maximilians-Universität Würzburg; Am Hubland 97074 Würzburg Deutschland
| | - Bret B. Macha
- Institut für Anorganische Chemie; Julius-Maximilians-Universität Würzburg; Am Hubland 97074 Würzburg Deutschland
| | - James D. Mattock
- Department of Chemistry, School of Life Sciences; University of Sussex; Brighton BN1 9QJ Sussex Großbritannien
| | - Franc Meyer
- Institut für Anorganische Chemie; Georg-August-Universität Göttingen; Tammannstraße 4 37077 Göttingen Deutschland
| | - Jan Mies
- Institut für Anorganische Chemie; Julius-Maximilians-Universität Würzburg; Am Hubland 97074 Würzburg Deutschland
| | - Marius Schäfer
- Institut für Anorganische Chemie; Julius-Maximilians-Universität Würzburg; Am Hubland 97074 Würzburg Deutschland
| | - Alfredo Vargas
- Department of Chemistry, School of Life Sciences; University of Sussex; Brighton BN1 9QJ Sussex Großbritannien
| |
Collapse
|
8
|
Böhnke J, Braunschweig H, Dellermann T, Ewing WC, Hammond K, Jimenez-Halla JOC, Kramer T, Mies J. Die Synthese von B2(SIDip)2und seine Reaktivität zwischen denen von Diboracumulenen und Diborinen. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201506368] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
9
|
Böhnke J, Braunschweig H, Dellermann T, Ewing WC, Hammond K, Jimenez-Halla JOC, Kramer T, Mies J. The Synthesis of B2(SIDip)2and its Reactivity Between the Diboracumulenic and Diborynic Extremes. Angew Chem Int Ed Engl 2015; 54:13801-5. [DOI: 10.1002/anie.201506368] [Citation(s) in RCA: 97] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Indexed: 11/11/2022]
|
10
|
Bertermann R, Braunschweig H, Constantinidis P, Dellermann T, Dewhurst RD, Ewing WC, Fischer I, Kramer T, Mies J, Phukan AK, Vargas A. Exklusiver π-Einschluss leichter Alkalimetallkationen durch ein neutrales Molekül. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201506487] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
11
|
Bertermann R, Braunschweig H, Constantinidis P, Dellermann T, Dewhurst RD, Ewing WC, Fischer I, Kramer T, Mies J, Phukan AK, Vargas A. Exclusive π Encapsulation of Light Alkali Metal Cations by a Neutral Molecule. Angew Chem Int Ed Engl 2015; 54:13090-4. [DOI: 10.1002/anie.201506487] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Indexed: 11/08/2022]
Affiliation(s)
- Rüdiger Bertermann
- Institut für Anorganische Chemie, Julius‐Maximilians‐Universität Würzburg, Am Hubland, 97074 Würzburg (Germany)
| | - Holger Braunschweig
- Institut für Anorganische Chemie, Julius‐Maximilians‐Universität Würzburg, Am Hubland, 97074 Würzburg (Germany)
| | - Philipp Constantinidis
- Institut für Physikalische und Theoretische Chemie, Julius‐Maximilians‐Universität Würzburg, Am Hubland, 97074 Würzburg (Germany)
| | - Theresa Dellermann
- Institut für Anorganische Chemie, Julius‐Maximilians‐Universität Würzburg, Am Hubland, 97074 Würzburg (Germany)
| | - Rian D. Dewhurst
- Institut für Anorganische Chemie, Julius‐Maximilians‐Universität Würzburg, Am Hubland, 97074 Würzburg (Germany)
| | - William C. Ewing
- Institut für Anorganische Chemie, Julius‐Maximilians‐Universität Würzburg, Am Hubland, 97074 Würzburg (Germany)
| | - Ingo Fischer
- Institut für Physikalische und Theoretische Chemie, Julius‐Maximilians‐Universität Würzburg, Am Hubland, 97074 Würzburg (Germany)
| | - Thomas Kramer
- Institut für Anorganische Chemie, Julius‐Maximilians‐Universität Würzburg, Am Hubland, 97074 Würzburg (Germany)
| | - Jan Mies
- Institut für Anorganische Chemie, Julius‐Maximilians‐Universität Würzburg, Am Hubland, 97074 Würzburg (Germany)
| | - Ashwini K. Phukan
- Department of Chemical Sciences, Tezpur University, Napaam 784028, Assam (India)
| | - Alfredo Vargas
- Department of Chemistry, School of Life Sciences, University of Sussex, Brighton BN1 9QJ, Sussex (UK)
| |
Collapse
|
12
|
Arnold T, Braunschweig H, Ewing WC, Kramer T, Mies J, Schuster JK. Beryllium bis(diazaborolyl): old neighbors finally shake hands. Chem Commun (Camb) 2015; 51:737-40. [PMID: 25417558 DOI: 10.1039/c4cc08519a] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The synthesis of a linear beryllium bis(diazaborolyl) compound featuring the first non-cluster bond between boron and beryllium has been achieved through the reaction of Yamashita's lithium diazaborolide and BeCl2. In accord with the established chemistry of beryllium, the bonding is polar covalent in character, as determined by structural and spectroscopic analysis, as well as reactivity studies.
Collapse
Affiliation(s)
- T Arnold
- Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.
| | | | | | | | | | | |
Collapse
|
13
|
Böhnke J, Braunschweig H, Constantinidis P, Dellermann T, Ewing WC, Fischer I, Hammond K, Hupp F, Mies J, Schmitt HC, Vargas A. Experimental Assessment of the Strengths of B–B Triple Bonds. J Am Chem Soc 2015; 137:1766-9. [DOI: 10.1021/ja5116293] [Citation(s) in RCA: 94] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Julian Böhnke
- Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Holger Braunschweig
- Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | | | - Theresa Dellermann
- Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - William C. Ewing
- Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Ingo Fischer
- Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Kai Hammond
- Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Florian Hupp
- Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Jan Mies
- Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | | | - Alfredo Vargas
- Department
of Chemistry, School of Life Sciences, University of Sussex, Brighton BN1 9QJ, Sussex, U.K
| |
Collapse
|
14
|
Braunschweig H, Damme A, Mies J, Schäfer M. Insertion of Chalcogens and Bis(tert-butylisonitrile)palladium(0) into a Strained Ruthenium Half-sandwich Complex. Zeitschrift für Naturforschung B 2014. [DOI: 10.5560/znb.2012-0242] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The previously synthesized strained distannadiyl-ansa half-sandwich complex [{k1-SntBu2- SntBu2-(η5-C5H5)}Ru(CO)2] was investigated with respect to its reactivity toward group 16 elements and bis(tert-butylisonitrile)palladium(0). All products were analyzed by multinuclear NMR spectroscopy, IR spectroscopy and elemental analysis. [{k1-SntBu2SSntBu2-(η5-C5H5)}Ru(CO)2] was furthermore characterized by X-ray diffraction.
Collapse
Affiliation(s)
- Holger Braunschweig
- Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Alexander Damme
- Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Jan Mies
- Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Marius Schäfer
- Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| |
Collapse
|
15
|
Böhnke J, Braunschweig H, Ewing WC, Hörl C, Kramer T, Krummenacher I, Mies J, Vargas A. Diborabutatrien: ein elektronenarmes Cumulen. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201403888] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
16
|
Böhnke J, Braunschweig H, Ewing WC, Hörl C, Kramer T, Krummenacher I, Mies J, Vargas A. Diborabutatriene: An Electron-Deficient Cumulene. Angew Chem Int Ed Engl 2014; 53:9082-5. [DOI: 10.1002/anie.201403888] [Citation(s) in RCA: 124] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Indexed: 11/08/2022]
|
17
|
Braunschweig H, Dellermann T, Dewhurst RD, Mies J, Radacki K, Stellwag-Konertz S, Vargas A. Strained ansa Half-Sandwich Complexes of Ruthenium and Osmium and a Non-Iron Metallopolymer by Ring-Opening Polymerization. Organometallics 2014. [DOI: 10.1021/om500111r] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Holger Braunschweig
- Institut für
Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Theresa Dellermann
- Institut für
Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Rian D. Dewhurst
- Institut für
Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Jan Mies
- Institut für
Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Krzysztof Radacki
- Institut für
Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Sascha Stellwag-Konertz
- Institut für
Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Alfredo Vargas
- Institut für
Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany
- Department of Chemistry, School of Life Sciences, University of Sussex, Brighton BN1 9QJ, Sussex, U.K
| |
Collapse
|
18
|
Braunschweig H, Dewhurst RD, Hammond K, Mies J, Radacki K, Vargas A. Ambient-Temperature Isolation of a Compound with a Boron-Boron Triple Bond. Science 2012; 336:1420-2. [DOI: 10.1126/science.1221138] [Citation(s) in RCA: 458] [Impact Index Per Article: 38.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
|
19
|
|
20
|
Braunschweig H, Dörfler R, Mies J, Oechsner A. Sterically Demanding Hetero-Substituted [2]Borametallocenophanes of Group IV Metals: Synthesis, Structure and Reactivity. Chemistry 2011; 17:12101-7. [DOI: 10.1002/chem.201101774] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2011] [Indexed: 11/10/2022]
|
21
|
Braunschweig H, Dörfler R, Hammond K, Mies J, Radacki K. Synthesis and Structure of Trisilane-1,3-diyl ansa Half-Sandwich Complexes of Group 6 Metals. Eur J Inorg Chem 2010. [DOI: 10.1002/ejic.201000965] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
22
|
Affiliation(s)
- Holger Braunschweig
- Institut für Anorganische Chemie, Julius‐Maximilians‐Universität Würzburg, Am Hubland, 97074 Würzburg, Germany, Fax: +49‐931‐888‐4623
| | - Thomas Kupfer
- Department of Chemistry 6‐421, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, Massachusetts 02139, USA
| | - Jan Mies
- Institut für Anorganische Chemie, Julius‐Maximilians‐Universität Würzburg, Am Hubland, 97074 Würzburg, Germany, Fax: +49‐931‐888‐4623
| | - Andreas Oechsner
- Institut für Anorganische Chemie, Julius‐Maximilians‐Universität Würzburg, Am Hubland, 97074 Würzburg, Germany, Fax: +49‐931‐888‐4623
| |
Collapse
|
23
|
Tasler S, Mies J, Lang M. Applicability Aspects of Transition Metal-Catalyzed Aromatic Amination Protocols in Medicinal Chemistry. Adv Synth Catal 2007. [DOI: 10.1002/adsc.200700133] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
24
|
Leban J, Baierl M, Mies J, Trentinaglia V, Rath S, Kronthaler K, Wolf K, Gotschlich A, Seifert MHJ. A novel class of potent NF-kappaB signaling inhibitors. Bioorg Med Chem Lett 2007; 17:5858-62. [PMID: 17869512 DOI: 10.1016/j.bmcl.2007.08.022] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2007] [Revised: 08/09/2007] [Accepted: 08/10/2007] [Indexed: 12/11/2022]
Abstract
A novel class of NF-kappaB pathway signaling inhibitors was discovered by virtual screening, medicinal chemistry, and QSAR analysis. An initial set of compounds inhibited NF-kappaB signaling in a whole cell reporter gene assay in the micro-molar range. Activity was improved step by step by medicinal chemistry to yield nano-molar signaling inhibitors.
Collapse
Affiliation(s)
- Johann Leban
- 4SC AG, Am Klopferspitz 19a, 82152 Martinsried, Germany.
| | | | | | | | | | | | | | | | | |
Collapse
|
25
|
Abstract
Human dihydroorotate dehydrogenase (DHODH) represents an important target for the treatment of hyperproliferative and inflammatory diseases. In the cell DHODH catalyzes the rate-limiting step of the de novo pyrimidine biosynthesis. DHODH inhibition results in beneficial immunosuppressant and antiproliferative effects in diseases such as rheumatoid arthritis. Here, we present high-resolution X-ray structures of human DHODH in complex with a novel class of low molecular weight compounds that inhibit the enzyme in the nanomolar range. Some compounds showed an interesting dual binding mode within the same cocrystal strongly depending on the nature of chemical substitution. Measured in vitro activity data correlated with the prevailing mode of binding and explained the observed structure-activity relationship. Additionally, the X-ray data confirmed the competitive nature of the inhibitors toward the putative ubiquinone binding site and will guide structure-based design and synthesis of molecules with higher activity.
Collapse
|
26
|
Leban J, Kralik M, Mies J, Baumgartner R, Gassen M, Tasler S. Biphenyl-4-ylcarbamoyl thiophene carboxylic acids as potent DHODH inhibitors. Bioorg Med Chem Lett 2006; 16:267-70. [PMID: 16246558 DOI: 10.1016/j.bmcl.2005.10.011] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2005] [Revised: 09/14/2005] [Accepted: 10/05/2005] [Indexed: 10/25/2022]
Abstract
A previously discovered DHODH inhibitor series was further improved by replacing the cyclopentene ring by aromatic heterocycles. Different isomers of these compounds were prepared by the directed ortho-metallation procedure. The compounds are more active than the corresponding cyclopentene analogs and show potent effects on PBMC's proliferation.
Collapse
Affiliation(s)
- Johann Leban
- 4SC AG, Am Klopferspitz 19a, 82152 Martinsried, Germany.
| | | | | | | | | | | |
Collapse
|
27
|
Leban J, Kralik M, Mies J, Gassen M, Tentschert K, Baumgartner R. SAR, species specificity, and cellular activity of cyclopentene dicarboxylic acid amides as DHODH inhibitors. Bioorg Med Chem Lett 2005; 15:4854-7. [PMID: 16143532 DOI: 10.1016/j.bmcl.2005.07.053] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2005] [Revised: 07/05/2005] [Accepted: 07/07/2005] [Indexed: 11/22/2022]
Abstract
Novel DHODH inhibitors were developed based on a previously described series by introduction of heteroatoms into the cyclopentene ring and hydroxyl groups attached to it. Also, the hydrophobic biphenyl side chain was replaced with benzyloxy phenyl groups. Activities on human, rat, and mouse enzymes indicate a species specificity of these inhibitors.
Collapse
Affiliation(s)
- Johann Leban
- 4SC AG, Am Klopferspitz 19a, 82152 Martinsried, Germany.
| | | | | | | | | | | |
Collapse
|
28
|
Meiering S, Inhoff O, Mies J, Vincek A, Garcia G, Kramer B, Dormeyer M, Krauth-Siegel RL. Inhibitors of Trypanosoma cruzi trypanothione reductase revealed by virtual screening and parallel synthesis. J Med Chem 2005; 48:4793-802. [PMID: 16033259 DOI: 10.1021/jm050027z] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In an approach to discover new inhibitors of trypanothione reductase from Trypanosoma cruzi, the causative agent of Chagas' disease, a virtual high-throughput screening was performed. Two structurally new types of inhibitors emerged, the antimicrobial chlorhexidine {1,1'-hexamethylenebis[5-(4-chlorophenyl)biguanide]}, a linear competitive inhibitor (K(i) = 2 +/- 1 microM), and a piperidine derivative acting as mixed inhibitor (K(i) = 6.2 +/- 2 microM and K(i)' = 8.5 +/- 2 microM). Neither compound interferes with human glutathione reductase. Based on chlorhexidine, different series of compounds were synthesized and studied as inhibitors of T. cruzi trypanothione reductase. Most efficient derivatives were three bis(amidines) showing mixed type inhibition with K(i,slope) and K(i,int) values of 2-5 microM and 16-47 microM, respectively. Although these compounds did not exert an improved inhibitory potency compared to chlorhexidine, the change from competitive to mixed-type inhibition is advantageous, since substrate accumulation does not overcome inhibition. Remarkably, all three derivatives carried two copies of an identical 2-methoxy-4-methyl-1-(phenylmethoxy)benzene substituent.
Collapse
Affiliation(s)
- Svea Meiering
- Biochemie-Zentrum, Universität Heidelberg, Im Neuenheimer Feld 504, D-69120 Heidelberg, Germany
| | | | | | | | | | | | | | | |
Collapse
|
29
|
Bringmann G, Saeb W, Rückert M, Mies J, Michel M, Mudogo V, Brun R. Ancistrolikokine D, a 5,8'-coupled naphthylisoquinoline alkaloid, and related natural products from Ancistrocladus likoko. Phytochemistry 2003; 62:631-636. [PMID: 12560038 DOI: 10.1016/s0031-9422(02)00570-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
A new naphthylisoquinoline alkaloid, ancistrolikokine D, and the likewise 5,8'-coupled alkaloid ancistroealaine A, as well as two further, biosynthetically related, but nitrogen-free natural products, ancistronaphthoic acid B and cis-isoshinanolone, have been isolated from Ancistrocladus likoko J. LEACUTE;ONARD (Ancistrocladaceae). The 5,8'-coupling of the new alkaloids and of the alkaloids isolated earlier hints at a close phylogenetic relationship of A. likoko to other Central African Ancistrocladus species. The compounds show moderate activities against Leishmania donovani, Trypanosoma cruzi, and Trypanosoma brucei rhodesiense.
Collapse
Affiliation(s)
- Gerhard Bringmann
- Institut für Organische Chemie der Universität, Am Hubland, D-97074 Würzburg, Germany.
| | | | | | | | | | | | | |
Collapse
|
30
|
Bringmann G, Günther C, Saeb W, Mies J, Wickramasinghe A, Mudogo V, Brun R. Ancistrolikokines A-C: new 5,8'-coupled naphthylisoquinoline alkaloids from Ancistrocladus likoko. J Nat Prod 2000; 63:1333-1337. [PMID: 11076547 DOI: 10.1021/np000199t] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Three new naphthylisoquinoline alkaloids, ancistrolikokines A-C (1-3), have been isolated and structurally assigned from Ancistrocladus likoko, as well as the known compound korupensamine A (4). Their 5,8'-coupling hints at a close biogenetic relationship of A. likoko to other Central African Ancistrocladus species. Compounds 1-4 showed good to moderate antimalarial activities when evaluated in vitro against the NF54 and K1 strains of Plasmodium falciparum.
Collapse
Affiliation(s)
- G Bringmann
- Institut für Organische Chemie der Universität, Am Hubland, D-97074 Würzburg, Germany, Department of Chemistry, University of Peradeniya, Peradeniya, Sri Lanka.
| | | | | | | | | | | | | |
Collapse
|
31
|
Bringmann G, Günther C, Saeb W, Mies J, Brun R, Assi LA. 8-O-methyldioncophyllinol B and revised structures of other 7,6'-coupled naphthylisoquinoline alkaloids from Triphyophyllum peltatum (Dioncophyllaceae). Phytochemistry 2000; 54:337-346. [PMID: 10870189 DOI: 10.1016/s0031-9422(00)00107-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The isolation and structural elucidation of a new naphthylisoquinoline alkaloid, 8-O-methyldioncophyllinol B, from Triphyophyllum peltatum (Hutch. et Dalz.) Airy Shaw (Dioncophyllaceae) is described, together with the revised structures of other 'B-type' compounds previously misidentified as dioncophylline D, dioncophyllinol D, and 8-O-methyldioncophylline D. All of the presently described structures are 7,6'-coupled and thus have to be addressed as 'B-type' naphthylisoquinoline alkaloids. This is in contrast to the initially defined 'D-type' structures, which are 7,8'-coupled as confirmed by a total synthesis of dioncophylline D. Some of these natural and synthetic naphthylisoquinolines were found to display good in vitro antiplasmodial activities.
Collapse
Affiliation(s)
- G Bringmann
- Institut für Organische Chemie, Universität Würzburg, Germany.
| | | | | | | | | | | |
Collapse
|
32
|
Bringmann G, Saeb W, Mies J, Messer K, Wohlfarth M, Brun R. One-Step Oxidative Dimerization of Genuine, Unprotected Naphthylisoquinolines Alkaloids to Give Michellamines and Other Bioactive Quateraryls. SYNTHESIS-STUTTGART 2000. [DOI: 10.1055/s-2000-8236] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
|
33
|
Mies J. [The aging heart and its treatment in general practice]. Dtsch Med J 1965; 16:528-530. [PMID: 5891383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
|