Treatment of Bi2O3 with the acids; S-(+)-10-camphorsulfonic, 2,4,6-mesitylenesulfonic and sulfamic, under sonication at room temperature in water for 2–4 h, results in the formation and subsequent crystallisation of polynuclear bismuth oxido-clusters; [Bi18O12(OH)12(O3S–Cam)18(H2O)2], [Bi38O45(O3S-Mes)24(H2O)14] and [Bi6O4(OH)4(O3SNH2)6].
