Magic-sized clusters (MSCs) can provide valuable insight into the atomically precise progression of semiconductor nanocrystal transformations. We report the conversion of an InP MSC to a Cd₃P₂ MSC through a cation exchange mechanism and attempt to shed light on the evolution of the physical and electronic structure of the clusters during the transformation. Utilizing a combination of spectroscopic (NMR/UV–vis) and structural characterization (ICP-OES/MS/PXRD/XPS/PDF) tools, we demonstrate retention of the original InP MSC crystal lattice as Z-type ligand exchange initially occurs. Further cation exchange induces lattice relaxation and a significant structural rearrangement. These observations contrast with reports of cation exchange in InP quantum dots, indicating unique reactivity of the InP MSC.

The reaction of primary amines with In₃₇P₂₀(O₂CR)₅₁ is found to remove In(O₂CR)₃ subunits from In₃₇P₂₀(O₂CR)₅₁. This loss of Z-type ligands coincides with structural rearrangement to alleviate core strain and passivate phosphorus atoms. This result consolidates conflicting claims that primary amines both promote and retard precursor conversion rates for InP nanocrystals.