An Anionic Amido-Substituted Seven-Vertex Siliconoid Cluster.

Area of Science:

• Inorganic Chemistry
• Materials Science
• Computational Chemistry

Background:

• The synthesis and characterization of silicon cluster compounds are crucial for developing novel materials.
• Understanding the electronic structure and bonding in silicon anions provides insights into silicon chemistry.

Purpose of the Study:

• To investigate the transformation of a silanide anion into a larger siliconoid cluster.
• To elucidate the electronic structure and magnetic properties of the resulting siliconoid cluster.

Main Methods:

• Reaction of [Si4 {N(SiMe3)Dipp}3]- with [K([18]crown-6)] in C6D6.
• Natural population analysis (NPA) and visualization of intrinsic atomic orbitals (IAO).
• Magnetically induced current-density (MICD) calculations.

Main Results:

• The silanide [Si4 {N(SiMe3)Dipp}3]- (1) was observed to transform into the anionic siliconoid cluster [Si7 {N(SiMe3)Dipp}3]- (2).
• Electronic investigations revealed two strong diatropic current vortices within the siliconoid cluster.
• These vortices contribute to a significant magnetic shielding effect on the apical silicon atom.

Conclusions:

• The transformation demonstrates a novel pathway for silicon cluster expansion.
• The electronic structure calculations confirm aromaticity in the siliconoid cluster.
• The observed magnetic shielding highlights unique electronic properties of the synthesized silicon cluster.