Organoantimony chemistry

[2] An organoantimony synthesis typically begins with tricoordinate antimony compounds, called stibines.

As soft Lewis donors, they see wide use in coordination chemistry[3]: 348  and typically react through oxidative addition: This property also sensitizes them to air.

If reduced instead, stibanes typically release substituents (ligands):[3]: 443 The cyclic compound stibole, a structural analog of pyrrole, has not been isolated, but substituted derivatives have.

They can be synthesised from stibines and halogens (Ph = C6H5): As confirmed by X-ray crystallography, dichlorostiboranes feature pentacoordinate Sb(V) with trans-diaxial chloride ligands.

Unsymmetrical stiboranes can also be obtained through the stibonium ions: Pentaphenylantimony decomposes at 200 °C to triphenylstibine and biphenyl.

Distibines are formally SbII compounds, but feature tricoordinate Sb atoms with a single Sb-Sb bond.

[6][3]: 442  A typical synthesis first displaces an SbIII halide with an alkali metal and then reduces the resulting anion with ethylene dichloride.

[8]: 403  However, stibanes poorly imitate active metal organometallics: only with difficulty do their ligands add to carbonyls or they power noble-metal cross couplings.

[8]: 406–408  In air, tris(thiophenyl)stibine catalyzes a Hunsdiecker-like decarboxylative oxidation of anhydrides to alcohols.