Pentasilacyclopentadienide: A Hückel aromatic species at the border of resonance and equilibrium | Science

Aromatic rings such as the ubiquitous π-ligand cyclopentadienide (C5H5−) adhere to the famous Hückel rule with their 4n+2 π cyclically delocalized electrons. Since the advent of stable Si–Si π-bonds in 1981, all-silicon aromatics have been targeted, yet ...