Cooperative Noncovalent Interactions Induce Ion Pair Separation in Diphenylsilanides.

This crystallographic and computational study describes an unusual potassium silanide structure. A contact ion pair is expected in the solid state between potassium and silicon, yet the potassium cation binds an aromatic ring and the anionic silanide interacts with CH bonds on neighboring crown ether molecules. These structure-bonding phenomena are attributed to strong soft-soft interactions.