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Updated: Nov 24, 2025
06:56
1,3,5-Triphenylbenzene and Corannulene as Electron Receptors for Lithium Solvated Electron Solutions
Published on: October 10, 2016
8.0K
Structural and electronic studies of substituted m-terphenyl lithium complexes
Andrew J Valentine1, Ana M Geer, Laurence J Taylor
1School of Chemistry, University of Nottingham, University Park, Nottingham, NG7 2RD, UK. Deborah.Kays@nottingham.ac.uk Jonathan.McMaster@nottingham.ac.uk.
Dalton Transactions (Cambridge, England : 2003)
|December 21, 2020
Summary
Para-substitution influences electronic properties of m-terphenyl lithium complexes. Electron-withdrawing groups cause upfield shifts in NMR spectra, indicating electronic variations despite structural similarity.
Area of Science:
- Organometallic Chemistry
- Lithium Chemistry
- Spectroscopy
Background:
- m-Terphenyl lithium complexes are valuable synthetic intermediates.
- Understanding substituent effects is crucial for tuning reactivity.
- Structural and electronic properties of organolithium compounds are key research areas.
Purpose of the Study:
- To investigate the impact of para-substitution on the structural and electronic characteristics of m-terphenyl lithium complexes.
- To correlate spectroscopic data with electronic substituent parameters.
- To elucidate the nature of interactions influencing observed spectral shifts.
Main Methods:
- Synthesis and X-ray crystallography of para-substituted m-terphenyl lithium complexes.
- Nuclear Magnetic Resonance (NMR) spectroscopy (7Li{1H} and 1H NMR).
- Two-dimensional 7Li-1H heteronuclear Overhauser spectroscopy (HOESY) and computational analysis.
Main Results:
- X-ray crystallography showed minimal structural variations across the series.
- NMR studies revealed significant electronic differences, correlating 7Li{1H} NMR chemical shifts with Hammett constants.
- Through-space LiH interactions were identified via HOESY, influencing proton NMR shifts.
- Electron-withdrawing substituents consistently led to upfield NMR peak shifts.
Conclusions:
- Para-substitution significantly impacts the electronic properties of m-terphenyl lithium complexes.
- NMR spectroscopy, particularly 7Li{1H} and 1H shifts, effectively probes these electronic variations.
- Through-space LiH interactions play a role in the observed spectroscopic trends.
- Computational methods support the experimental findings on substituent effects.
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