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Non-covalent bonds in group 1 and group 2 elements: the 'alkalene bond'
1Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore 560012, India. arunan@iisc.ac.in.
Physical Chemistry Chemical Physics : PCCP
|November 23, 2022
Summary
This study analyzes non-covalent bonds in alkali and alkaline earth metals using computational methods. A strong correlation between electron density and binding energy was found, leading to the proposal of the
Area of Science:
- Computational Chemistry
- Quantum Chemistry
- Materials Science
Background:
- Non-covalent interactions are crucial in chemistry and materials science.
- Understanding bonding in alkali and alkaline earth metals is essential for various applications.
- Systematic analysis of these weak bonds requires advanced computational techniques.
Purpose of the Study:
- To systematically analyze non-covalent bonds formed by group 1 and group 2 elements.
- To classify weak bonds based on computational data and theoretical analysis.
- To propose a unified nomenclature for these interactions.
Main Methods:
- Utilized ab initio calculations at the MP2/aug-cc-pVDZ level of theory.
- Employed Atoms in Molecules (AIM) analysis on computed wave functions.
- Investigated a range of donor and acceptor molecules to establish correlations.
Main Results:
- Established a strong correlation between electron density at the bond critical point (BCP) and binding energy.
- Quantified the relationship using the slopes of electron density versus binding energy plots.
- Identified similarities in bonding characteristics for group 1 (excluding H-bonds) and group 2 elements.
Conclusions:
- The bonding in alkali and alkaline earth metals is largely electrostatic, characterized by a high slope in the density-energy plot.
- Proposed the term 'alkalene bond' to encompass non-covalent bonding involving alkali and alkaline earth metals.
- This classification provides a framework for understanding and predicting these weak interactions.
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