The dicarbon bonding puzzle viewed with photoelectron imaging

Abstract

In spite of its apparent simplicity, the dicarbon molecule has a bonding structure which is matter of debate. Here the authors measure high-resolution spectra of the $${{\mathrm{C}}}_{2}$$ C2 anion by photoelectron imaging, revealing a bonding configuration dominated by a double $$\pi$$ π bond, with no accompanying $$\sigma$$ σ bond.