Our next task was to reduce the size from µm to nm by 10 9 in volume. Gibbs' classical nucleation theory tells us that reduction of the surface energy of forming crystal nuclei results in the production of more nuclei and hence reduction of their sizes . We found that the addition of OAM dramatically reduced the QD size. With 0.15 equiv of OAM per PbBr2 following the synthesis procedure for 2, we formed a stable green-emitting solution of QD irregular cubic particles of 10.6 ± 2 nm (measured on amorphous carbon, aC, using TEM, Fig. ). With 1.5 equiv OAM, we obtained a stable colloidal suspension of blue-emitting magic-sized nanoclusters with the size further decreased to »2.5 nm on aC (Fig. ). Note that saturated linear C8, C12, and C18 amines and benzylamine failed to produce a stable suspension in either toluene, chlorobenzene, or 1,2-dichlorobenzene. The crucial role of the cis-olefinic bond in OAM is therefore evident.