Gold as a 6p-Element in Dense Lithium Aurides
Guochun Yang1,2, Yanchao Wang1, Feng Peng1
1State Key Laboratory of Superhard Materials, Jilin University , Changchun 130012, China.
Journal of the American Chemical Society
|March 5, 2016
Summary
High pressure enables the creation of gold (Au) compounds with unprecedentedly high negative oxidation states. These novel aurides exhibit unique structures and properties, expanding the chemistry of gold anions.
Area of Science:
- Materials Science
- Solid State Chemistry
- Computational Chemistry
Background:
- Negative oxidation states of gold (Au) are rare but exhibit unique properties like ferroelectricity.
- Previous research has only confirmed monatomic anionic gold (Au(-)).
- Higher negative oxidation states for gold have remained elusive.
Purpose of the Study:
- To explore the possibility of achieving higher negative oxidation states for gold.
- To investigate the reaction of gold with alkali metals under high pressure.
- To discover novel gold-containing compounds with unusual stoichiometries and structures.
Main Methods:
- First-principles calculations were employed.
- Swarm structural searches were utilized to predict stable phases.
- High-pressure synthesis conditions were proposed.
Main Results:
- Stable lithium-rich aurides (e.g., Li4Au, Li5Au) were predicted under high pressure.
- These compounds feature unique structures, including Au-centered polyhedrons and a graphene-like Li sublattice.
- Gold atoms in these compounds exhibit high negative oxidation states, acting as 6p-elements.
- Similar high negative oxidation states were observed for gold reacting with other alkali metals like Cesium (Cs) under pressure.
Conclusions:
- High pressure is a viable method for synthesizing gold compounds with high negative oxidation states.
- This approach allows for the creation of diverse gold anions with novel structural motifs.
- The findings open new avenues for exploring exotic properties of gold-based materials.
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