The Kläui ligand is the anion
−. The
ligand
In coordination chemistry, a ligand is an ion or molecule ( functional group) that binds to a central metal atom to form a coordination complex. The bonding with the metal generally involves formal donation of one or more of the ligand's ele ...
, popularized by
Wolfgang Kläui
Wolfgang is a German male given name traditionally popular in Germany, Austria and Switzerland. The name is a combination of the Old High German words ''wolf
The wolf (''Canis lupus''; : wolves), also known as the gray wolf or grey wo ...
, binds metals and
metalloids via a facial O
3 donor set. Related
tridentate and
tripodal anionic ligands include
trispyrazolylborates.
:
160px, General structure of a metal center coordinated to a κ3-Kläui ligand.
The ligand is derived from the cationic complex of
trimethylphosphite
Trimethyl phosphite is an organophosphorus compound with the formula P(OCH3)3, often abbreviated P(OMe)3. It is a colorless liquid with a highly pungent odor. It is the simplest phosphite ester and finds used as a ligand in organometallic che ...
2+ via an
Arbuzov reaction Arbuzov (masculine, russian: Арбузов) or Arbuzova (feminine, russian: Арбузовa) is a Russian surname, derived from the word арбуз (''arbooz'', meaning "watermelon
Watermelon (''Citrullus lanatus'') is a flowering plant spec ...
. Using other
phosphite
The general structure of a phosphite ester showing the lone pairs on the P
In organic chemistry, a phosphite ester or organophosphite usually refers to an organophosphorous compound with the formula P(OR)3. They can be considered as esters of ...
s and other
cyclopentadienyl Cyclopentadienyl can refer to
* Cyclopentadienyl anion, or cyclopentadienide,
**Cyclopentadienyl ligand
A cyclopentadienyl complex is a coordination complex of a metal and cyclopentadienyl anion, cyclopentadienyl groups (, abbreviated as Cp−) ...
ligands, a large variety of derivatives are possible. The parent acid H is highly soluble in water (270 g/100 mL). Its p''K''
a is about 2. Many complexes have been described, including bis(
chelate
Chelation is a type of bonding of ions and molecules to metal ions. It involves the formation or presence of two or more separate coordinate bonds between a polydentate (multiple bonded) ligand and a single central metal atom. These ligands are ...
) complexes of the type {M
(C5H5)Co[(CH3O)2POsub>3}
2]
n+ (M = Co(II), Mn(II), Bi(III), etc.).
[Wolfgang Kläui, Heiko Otto, Werner Eberspach, Elke Buchholz "Die Michaelis-Arbusov-Reaktion als Zugang zu neuen Sauerstoff-Tripodliganden des Typs 5R5M{P(O)(OCH3)2}3sup>−. Ligandfeldspektroskopische und koordinationschemische Charakterisierung der Liganden" Chemische Berichte 1982, Volume 115, Pages 1922–1933. ]
References
{{DEFAULTSORT:Klaui Ligand
Organocobalt compounds
Half sandwich compounds
Cyclopentadienyl complexes
Phosphites
Tripodal ligands
