A supported Cr–Cr sextuple bond in an all-metal cluster

Abstract

Herein, we report a distinct Cr–Cr sextuple bond with an ultra-short length stabilized by equatorial alkali metals. Bonding analyses indicate that the two desired 4p–pi bonds failed to be formed but the bonding strength is enhanced due to the introduction of alkali metals, weakening the Cr–Cr 4s–4s effect. The Cr–Cr sextuple bond comprises five explicit 3d–3d overlaps and another delocalized σ bond.