Pentamethylbismuth

Pentamethylbismuth (or pentamethylbismuthorane) is an organometalllic compound containing five methyl groups bound to a bismuth atom with formula Bi(CH3)5. It is an example of a hypervalent compound. The molecular shape is trigonal bipyramid.

==Production== Pentamethylbismuth is produced in a two step process. First, trimethylbismuth is reacted with sulfuryl chloride to yield dichloro trimethylbismuth, which is then reacted with two equivalents of methyllithium dissolved in ether. The blue solution is cooled to −110 °C to precipitate the solid product. Bi(CH3)3 + SO2Cl2 → Bi(CH3)3Cl2 + SO2 Bi(CH3)3Cl2 + 2LiCH3 → Bi(CH3)5 + 2LiCl