Remarkably Short Metal–Metal Bonds: A Lantern‐Type Quintuply Bonded Dichromium(I) Complex

Abstract

The shortest metal–metal bond so far is found in complex anion 2 (CrCr 1.7397(9) Å), which is the one-electron reduction product of thermally stable mixed-valent complex 1 (see scheme). Experimental data unambiguously show that the electronic configuration of 1 is σ2π4δ3, and theoretical studies confirm the presence of a CrCr quintuple bond in 2. Ar=2,6-C6H3(CH3)2.