title: The shortest metal-metal bond.
abstract: The synthesis and isolation of stable bimetallic complexes that contain formally quintuply bonded transition metals is a novel and emerging field of science. Efforts have been undertaken in designing and tuning the ligands to achieve a very short (actually the shortest) metal-metal bond. The motivation for these efforts arose from the expectation that an increasing bond order may go along with a shortening of the bond length. In consequence, formally quintuply bonded bimetallics could have shorter metal-metal distances than quadruply bonded ones. A chromium homo-bimetallic complex with a Cr-Cr bond length of 1.7293(12) Å has been synthesized, and a formal bond order of five was assigned. This compound holds the record for the shortest metal-metal bond in a stable molecule to date. At this stage, there is no evidence that additional shortening is impossible.
authors.affiliation: Lehrstuhl Anorganische Chemie II, Universität Bayreuth, 95440 Bayreuth, Germany.
authors.forename: Awal
authors.initials: A
authors.lastname: Noor
authors.forename: Rhett
authors.initials: R
authors.lastname: Kempe