D _4h OMg₄S₄^2-: a global minimum featuring a planar tetracoordinate oxygen

Area of Science:

• Inorganic Chemistry
• Computational Chemistry
• Materials Science

Background:

• Planar hypercoordinate oxygen clusters are difficult to synthesize due to oxygen's high electronegativity and bonding versatility.
• Previous research has primarily focused on covalent bonding in hypercoordinate systems.

Purpose of the Study:

• To theoretically design and verify a stable planar hypercoordinate oxygen cluster.
• To investigate the bonding nature responsible for the stability of planar oxygen clusters.

Main Methods:

• Density Functional Theory (DFT) calculations were employed.
• Global minimum search and vibrational frequency analysis were performed to confirm dynamic stability.

Main Results:

• A novel OMg4S42- cluster with a planar tetracoordinate oxygen was successfully designed.
• The designed cluster was found to be a dynamically stable global minimum.
• Analysis revealed that electrostatic interactions, not covalent interactions, are key to its planar configuration.

Conclusions:

• The theoretical design of OMg4S42- demonstrates the feasibility of stable planar hypercoordinate oxygen clusters.
• This finding challenges conventional bonding theories and opens new avenues for designing novel inorganic materials.