Kläui ligand
Encyclopedia
The Kläui ligand is the anion {(C5H5)Co[(CH3O)2PO]3}-. The ligand
, popularlized by Wolfgang Kläui, binds metals and metalloids via a facial O3 donor set. Related tridentate anionic ligands include trispyrazolylborate and cyclopentadienyl
anions.
The ligand is derived from the cationic complex of trimethylphosphite {(C5H5)Co[P(OCH3)3]3}2+ via an Arbuzov reaction. 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). Its pKa is about 2. Many complexes have been described, including bis(chelate) complexes of the type {M[{(C5H5)Co[(CH3O)2PO]3}2]n+ (M = Co(II), Mn(II), Bi(III), etc.).
Ligand
In coordination chemistry, a ligand is an ion or molecule that binds to a central metal atom to form a coordination complex. The bonding between metal and ligand generally involves formal donation of one or more of the ligand's electron pairs. The nature of metal-ligand bonding can range from...
, popularlized by Wolfgang Kläui, binds metals and metalloids via a facial O3 donor set. Related tridentate anionic ligands include trispyrazolylborate and cyclopentadienyl
Cyclopentadienyl
In organic chemistry, cyclopentadienyl is a cyclic group of atoms with the formula C5H5. Cyclopentadienyl are closely related to cyclopentadiene. Cyclopentadienyl have five carbon atoms bonded together in a pentagonal planar ring, all five of which are bonded to individual hydrogen atoms...
anions.
The ligand is derived from the cationic complex of trimethylphosphite {(C5H5)Co[P(OCH3)3]3}2+ via an Arbuzov reaction. 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). Its pKa is about 2. Many complexes have been described, including bis(chelate) complexes of the type {M[{(C5H5)Co[(CH3O)2PO]3}2]n+ (M = Co(II), Mn(II), Bi(III), etc.).