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Luder DJ, Terefenko N, Sun Q, Eckert H, Mück-Lichtenfeld C, Kehr G, Erker G, Wiegand T. Polar covalent apex-base bonding in borapyramidanes probed by solid-state NMR and DFT calculations. Chemistry 2024; 30:e202303701. [PMID: 38078510 DOI: 10.1002/chem.202303701] [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: 11/07/2023] [Indexed: 01/04/2024]
Abstract
Pyramidane molecules have attracted chemists for many decades due to their regular shape, high symmetry and their correspondence in the macroscopic world. Recently, experimental access to a number of examples has been reported, in particular the rarely reported square pyramidal bora[4]pyramidanes. To describe the bonding situation of the nonclassical structure of pyramidanes, we present solid-state Nuclear Magnetic Resonance (NMR) as a versatile tool for deciphering such bonding properties for three now accessible bora[4]pyramidane and dibora[5]pyramidane molecules. 11 B solid-state NMR spectra indicate that the apical boron nuclei in these compounds are strongly shielded (around -50 ppm vs. BF3 -Et2 O complex) and possess quadrupolar coupling constants of less than 0.9 MHz pointing to a rather high local symmetry. 13 C-11 B spin-spin coupling constants have been explored as a measure of the bond covalency in the borapyramidanes. While the carbon-boron bond to the -B(C6 F5 )2 substituents of the base serves as an example for a classical covalent 2-center-2-electron (2c-2e) sp2 -carbon-sp2 -boron σ-bond with 1 J(13 C-11 B) coupling constants in the order of 75 Hz, those of the boron(apical)-carbon(basal) bonds in the pyramid are too small to measure. These results suggest that these bonds have a strongly ionic character, which is also supported by quantum-chemical calculations.
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Affiliation(s)
- Dominique J Luder
- Institute of Technical and Macromolecular Chemistry, RWTH Aachen University, Worringerweg 2, 52074, Aachen, Germany
- Laboratory of Physical Chemistry, ETH Zürich, Vladimir-Prelog-Weg 2, 8093, Zürich, Switzerland
| | - Nicole Terefenko
- Institute of Technical and Macromolecular Chemistry, RWTH Aachen University, Worringerweg 2, 52074, Aachen, Germany
| | - Qiu Sun
- Organische Chemie, University of Münster, Corrensstr. 36, 48149, Münster, Germany
| | - Hellmut Eckert
- Instituto de Física de São Carlos, Universidade de São Paulo, São Carlos, SP 13566-590, Brazil
- Institut für Physikalische Chemie, University of Münster, Corrensstr. 30, 48149, Münster, Germany
| | | | - Gerald Kehr
- Organische Chemie, University of Münster, Corrensstr. 36, 48149, Münster, Germany
| | - Gerhard Erker
- Organische Chemie, University of Münster, Corrensstr. 36, 48149, Münster, Germany
| | - Thomas Wiegand
- Institute of Technical and Macromolecular Chemistry, RWTH Aachen University, Worringerweg 2, 52074, Aachen, Germany
- Max Planck Institute for Chemical Energy Conversion, Stiftstr. 34-36, 45470, Mülheim, Germany
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Saouli I, Landron S, Peric B, Boutarfaia A, Kouvatas C, Le Pollès L, Cuny J, Gautier R. Computing of 93Nb NMR Parameters of Solid-State Niobates. The Geometry Matters. J STRUCT CHEM+ 2019. [DOI: 10.1134/s0022476619030090] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Zhou B, Sun W, Zhao BC, Mi JX, Laskowski R, Terskikh V, Zhang X, Yang L, Botis SM, Sherriff BL, Pan Y. 11B MAS NMR and First-Principles Study of the [OBO3] Pyramids in Borates. Inorg Chem 2016; 55:1970-7. [DOI: 10.1021/acs.inorgchem.5b02071] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Bing Zhou
- College of Materials Science and Engineering, Tongji University, Shanghai 200092, China
| | - Wei Sun
- Department of Geological Sciences, University of Saskatchewan, Saskatoon, SK S7N 5E2, Canada
- Fujian Provincial Key Laboratory of Advanced Materials,
Department of Materials Science and Engineering, College of Materials, Xiamen University, Xiamen 361005, Fujian China
| | - Biao-Chun Zhao
- Fujian Provincial Key Laboratory of Advanced Materials,
Department of Materials Science and Engineering, College of Materials, Xiamen University, Xiamen 361005, Fujian China
| | - Jin-Xiao Mi
- Fujian Provincial Key Laboratory of Advanced Materials,
Department of Materials Science and Engineering, College of Materials, Xiamen University, Xiamen 361005, Fujian China
| | - Robert Laskowski
- Institute of High Performance Computing, A*STAR, 1 Fusionopolis
Way, No. 16-16, Connexis 138632, Singapore
| | - Victor Terskikh
- Department of Chemistry, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - Xi Zhang
- Shanghai Key Laboratory of Magnetic Resonance, East China Normal University, Shanghai 200062, China
| | - Lingyun Yang
- Shanghai Key Laboratory of Magnetic Resonance, East China Normal University, Shanghai 200062, China
| | - Sanda M. Botis
- Department of Geological Sciences, University of Saskatchewan, Saskatoon, SK S7N 5E2, Canada
| | - Barbara L. Sherriff
- Department of Geological Sciences, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
| | - Yuanming Pan
- Department of Geological Sciences, University of Saskatchewan, Saskatoon, SK S7N 5E2, Canada
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