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Updated: Jul 26, 2025
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Determination of Thermodynamic Properties of Alkaline Earth-liquid Metal Alloys Using the Electromotive Force Technique
Published on: November 3, 2017
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A Blueprint for the Stabilization of Sub-Valent Alkaline Earth Complexes
Alex W J Bowles1, Yu Liu1, Matthew P Stevens1
1School of Chemistry, University of Leicester, University Road, Leicester, LE1 7RH, UK.
Chemistry (Weinheim an Der Bergstrasse, Germany)
|June 20, 2023
Summary
Researchers developed a new method to stabilize sub-valent heavy alkaline earth metal (AE) complexes. This breakthrough utilizes planar coordination geometries and shows potential for creating novel AE(I) compounds.
Area of Science:
- Inorganic Chemistry
- Main Group Chemistry
- Organometallic Chemistry
Background:
- Sub-valent Group 2 chemistry, particularly Mg(I) dimers, was established in 2007.
- Stabilizing heavier alkaline earth (AE) metals in sub-valent states presents significant synthetic challenges due to unstable AE-AE interactions.
Purpose of the Study:
- To present a novel strategy for stabilizing heavy AE(I) complexes.
- To explore the synthesis and characterization of AE(II) precursors with planar coordination geometries.
Main Methods:
- Synthesis and structural characterization of homoleptic trigonal planar AE(II) complexes using amide ligands.
- Density Functional Theory (DFT) calculations to analyze frontier orbital character.
- Natural Bond Orbital (NBO) calculations to assess electronic structure changes upon reduction.
Main Results:
- Successfully synthesized and characterized trigonal planar AE(II) complexes (AE = Ca-Ba) with amide ligands.
- DFT calculations revealed d-orbital character in the LUMOs of AE(II) complexes (AE = Ca-Ba) and square planar Sr(II) complex.
- Computational modeling indicated exergonic formation of AE(I) complexes upon reduction of AE(II) precursors.
- NBO calculations showed preserved d-orbital character in the SOMO of theoretical AE(I) products.
Conclusions:
- A new blueprint for stabilizing heavy AE(I) complexes has been established.
- The presence of d-orbital character in AE(II) precursors is crucial for the potential stabilization of heavy AE(I) complexes.
- This research opens avenues for exploring novel sub-valent heavy alkaline earth metal chemistry.
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