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Experimental Approaches for the Synthesis of Low-Valent Metal-Organic Frameworks from Multitopic Phosphine Linkers
Published on: May 12, 2023
Mixed donor-functionalised phosphinomethanide complexes of the alkali metals; synthesis, structures, and solution
Corinne Wills1, Keith Izod, Jonathan Young
1Main Group Chemistry Laboratories, School of Chemistry, Bedson Building, University of Newcastle, Newcastle upon Tyne, UK NE1 7RU.
Dalton Transactions (Cambridge, England : 2003)
|May 8, 2010
Summary
Researchers synthesized novel alkali metal phosphinomethanides from a mixed donor tertiary phosphine. Variable-temperature NMR and DFT calculations revealed dynamic conformational equilibria in solution, influenced by carbanion proximity.
Area of Science:
- Organometallic Chemistry
- Main Group Chemistry
- Coordination Chemistry
Background:
- Tertiary phosphines with mixed donor ligands are crucial in catalysis and materials science.
- Understanding the structural dynamics and electronic properties of phosphine derivatives is key to designing new functional molecules.
Purpose of the Study:
- To synthesize and characterize novel alkali metal phosphinomethanides.
- To investigate the solution dynamics and conformational behavior of these compounds.
- To elucidate the electronic factors influencing their structural properties.
Main Methods:
- Stepwise synthesis involving organolithium reagents and dichlorophosphines.
- Metathesis reactions with alkali metal alkoxides.
- Solid-state structural analysis using X-ray diffraction.
- Variable-temperature Nuclear Magnetic Resonance (NMR) spectroscopy.
- Density Functional Theory (DFT) calculations and GIAO NMR shielding tensor analysis.
Main Results:
- Successful synthesis of sodium (12) and potassium (13) phosphinomethanides.
- Solid-state structures reveal monomeric (12) and dimeric (13) arrangements.
- Variable-temperature NMR demonstrates significant fluxionality in solution due to conformational equilibria.
- DFT calculations confirm low energy differences between conformers and explain NMR chemical shifts through proximity to the carbanion.
Conclusions:
- The synthesized alkali metal phosphinomethanides exhibit rich solution dynamics governed by ligand orientation.
- Computational studies provide insights into the electronic and structural factors driving this fluxionality.
- The findings contribute to the understanding of bonding and reactivity in organophosphorus compounds.
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