[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.