biostudies-literatureAbecassis BBasic Energy SciencesNational Science Foundation4977-4983https://www.ebi.ac.uk/biostudies/studies/S-EPMC9067564biostudies-literatureUnknown13(17)Modern syntheses of colloidal nanocrystals yield extraordinarily narrow size distributions that are believed to result from a rapid "burst of nucleation" (La Mer, <i>JACS</i>, 1950, <b>72</b>(11), 4847-4854) followed by diffusion limited growth and size distribution focusing (Reiss, <i>J. Chem. Phys.</i>, 1951, <b>19</b>, 482). Using a combination of <i>in situ</i> X-ray scattering, optical absorption, and ¹³C nuclear magnetic resonance (NMR) spectroscopy, we monitor the kinetics of PbS solute generation, nucleation, and crystal growth from three thiourea precursors whose conversion reactivity spans a 2-fold range. In all three cases, nucleation is found to be slow and continues during >50% of the precipitation. A population balance model based on a size dependent growth law (1/Chemical sciencePersistent nucleation and size dependent attachment kinetics produce monodisperse PbS nanocrystals.PMC9067564DE-AC02-05CH11231CHE-2004008DeRosha DMcMurtry BMPeters BBennett EGreenberg MWOwen JSGuillemeney LAbecassis BBal VCampos MPSharpnack LHendricks MPMahler BPrevost SSaenz NfalsePersistent nucleation and size dependent attachment kinetics produce monodisperse PbS nanocrystals.Modern syntheses of colloidal nanocrystals yield extraordinarily narrow size distributions that are believed to result from a rapid "burst of nucleation" (La Mer, <i>JACS</i>, 1950, <b>72</b>(11), 4847-4854) followed by diffusion limited growth and size distribution focusing (Reiss, <i>J. Chem. Phys.</i>, 1951, <b>19</b>, 482). Using a combination of <i>in situ</i> X-ray scattering, optical absorption, and ¹³C nuclear magnetic resonance (NMR) spectroscopy, we monitor the kinetics of PbS solute generation, nucleation, and crystal growth from three thiourea precursors whose conversion reactivity spans a 2-fold range. In all three cases, nucleation is found to be slow and continues during >50% of the precipitation. A population balance model based on a size dependent growth law (1/2022-01-01T00:00:00Z2022 May2025-05-18T13:23:24.177Z2024-12-04T09:14:21.025ZS-EPMC90675643565587310.1039/d1sc06134h