Kläui ligand

The ligand, popularized by Wolfgang Kläui, binds metals and metalloids via a facial O3 donor set.

[1] Related tridentate and tripodal anionic ligands include trispyrazolylborates.

The ligand is derived from the cationic complex of trimethylphosphite {(C5H5)Co[P(OCH3)3]3}2+ via an Arbuzov reaction.

[2] Using other phosphites and other cyclopentadienyl ligands, a large variety of derivatives are possible.

The parent acid {(C5H5)Co[(CH3O)2PO]3}H is highly soluble in water (270 g/100 mL).

General structure of a metal center (ML n ) coordinated to a κ 3 -Kläui ligand.