CBe5E- (E = Al, Ga, In, Tl): planar pentacoordinate carbon in heptaatomic clusters

Area of Science:

• Computational Chemistry
• Materials Science
• Inorganic Chemistry

Background:

• Pentacoordinate carbon is a rare bonding motif.
• Understanding novel bonding in clusters is crucial for materials design.

Purpose of the Study:

• To theoretically investigate the existence and stability of planar pentacoordinate carbon in CBe(5)E(-) clusters.
• To elucidate the bonding characteristics and structural framework of these novel cluster systems.

Main Methods:

• Density Functional Theory (DFT) calculations were employed.
• Structural, electronic, and bonding analyses were performed.

Main Results:

• A series of CBe(5)E(-) clusters (E = Al, Ga, In, Tl) were predicted to possess a planar pentacoordinate carbon atom.
• The stable structures exhibit a planar EBe(4) ring with an in-plane Be capping atom.
• The central carbon atom acts as an electron acceptor within a multicenter σ-bond network and donates charge through π systems.

Conclusions:

• The theoretical findings confirm the feasibility of planar pentacoordinate carbon in these beryllium-based clusters.
• The unique bonding network, involving multicenter σ and π interactions, is key to stabilizing these unusual structures.
• These results open avenues for designing new materials with exotic coordination geometries.