Mechanistic Study of the Role of Primary Amines in Precursor Conversions to Semiconductor Nanocrystals at Low Temperature

Primary alkyl amines (RNH2) have been empirically used to engineer various colloidal semiconductor nanocrystals (NCs). Here, we present a general mechanism in which the amine acts as a hydrogen/proton donor in the precursor conversion to nanocrystals at low temperature, which was assisted by the presence of a secondary phosphine. Our findings introduce the strategy of using a secondary phosphine together with a primary amine as new routes to prepare high‐quality NCs at low reaction temperatures but with high particle yields and reproducibility and thus, potentially, low production costs. Identifying roles: 31P NMR and absorption spectroscopy was used in conjunction with DFT calculations to identify the reaction pathways leading to semiconductor nanocrystals (NCs), together with compounds 1–4 (see scheme). With SePPh2H as the Se precursor instead of SeP(C8H17)3, the conversion takes place at low temperature. The amine contributes to the formation of the two nitrogen compounds 1 and 2.