Reaction Intermediates in the Synthesis of Colloidal Nanocrystals

Over the past 40 years, scientists have learned to synthesize colloidal nanocrystals of different composition with tunable size and shape. These features dictate the properties of these nanomaterials. Thus, their control is crucial for the discovery of phenomena, many of which contribute to technological advances. One example of the societal impact of this class of materials is the use of semiconductor nanocrystals as the active component in displays with the best color purity on the market. A second example is their use as materials platforms to advance catalyst development. Yet, the synthesis of colloidal nanocrystals still proceeds by trial and error. The search for the reaction conditions to obtain the nanocrystals with the desired composition, size and shape is time consuming and can fail in delivering the target product.<br/> <br/>In this talk, I will highlight the importance of identifying the reaction intermediates during the formation of colloidal nanocrystals for the development of a more predictive synthesis to these nanomaterials. By discussing specific examples, I will illustrate that the chemical nature of these intermediates is diverse and that state-of-the-art in-situ techniques combined with theory are often needed to capture those transient species during the synthesis of nanocrystals. Nevertheless, I will use concrete examples to demonstrate that such efforts are worth it as the discovered mechanistic pathways pinpoint the critical steps to enhance the tunability of existing materials and to accelerate the discover of new ones.