Metallacrown

In chemistry, metallacrowns are a macrocyclic compounds that consist of metal ions and solely or predominantly heteroatoms in the ring.

First discovered by Vincent L. Pecoraro and Myoung Soo Lah in 1989,[1] metallacrowns are best described as inorganic analogues of crown ethers.

[2] Metallacrowns form via self-assembly, i.e. by dissolving the ligand in a solvent followed by the desired metal salt.

Metallacrowns typically contain fused chelate rings in their structure, which imparts them with substantial stability.

Inverse metallacrowns have been reported that contain metal ions oriented towards the center of the ring.

[4] Metallacrowns with gadolinium as the central metal are potential MRI contrast agents.

[8] Metallacrown container molecules constructed from the 15-MC-5 structure type have been shown to selectively encapsulate carboxylate anions in hydrophobic cavities.