Addressing a "Black Box" of Bottom-Up Synthesis: Revealing the Structures of Growing Colloidal-Nanocrystal Nuclei.

In bottom-up synthesis, products from reactions of structural building units rapidly pass from soluble molecular complexes to nanoscale intermediates, whose solution-state structures defy elucidation by any routine method. To address this, electron diffraction is used to reveal the structures of cryogenically "trapped" colloidal nanocrystals.