Metal-Metal Distances at the Limit: Cr-Cr 1.73 angstrom - the Importance of the Ligand and its Fine Tuning

The synthesis and structure of a homobimetallic chromium complex is reported. The ligand used to stabilise the quintuply bonded metals is a sterically fine-tuned guanidinate. A chromium-chromium bond length of 1.7293(12) angstrom was observed. It is the shortest metal-metal distance reported for a stable compound yet.