Fischer's lab team designed the material by building compounds made of individual copper and aluminum atoms. For this superatom, a mixture of aluminium atoms complexed with pentamethylcyclopentadiene (Cp*) and copper atoms complexed with mesitylene (Mes) were combined in an inert atmosphere.
:[AlCp*] + [CuMes] → [CuAl](Cp*)
After adding a solvent, the copper and aluminum atoms spontaneously separated from the organic compounds and formed the superatom cluster. The exergonic nature of the reaction demonstratesg that this specific arrangement of copper and aluminum atoms is stable.