Compounds of Bismuth

Less reduced intermetallic phases with the alkali metals and alkaline-earth metals are also known. Examples include MBi (M = Li, Na), MBi2 (M = K, Rb, Cs), and MʹBi3 (M = Mg, Ca, Sr, Ba). The compounds MʹBi3 (Mʹ = Ca, Sr, or Ba) superconduct at low temperatures. Some of these intermetallic phases have been extracted with amine solvents to yield anionic bismuth clusters in solution - http://www.science-chemistry.com/compounds-of-bismuth