Calixarene-Mediated Synthesis of Cobalt Nanoparticles: An Accretion Model for Separate Control over Nucleation and Growth.

ABSTRACT: The nucleation and growth of crystalline cobalt nanoparticles (Co NPs) under solvothermal conditions can be separated into distinct stages by using (i) polynuclear clusters with multivalent capping ligands to initiate nucleation, and (ii) thermolabile organometallic complexes with low autonucleation potential to promote crystalline growth. Both nucleation and growth take place within an amorphous accretion, formed in the presence of polyvalent surfactants. At the pre-nucleation stage, a calixarene complex with multiple Co₂-alkyne ligands (Co₁₆-calixarene 1) undergoes thermal decomposition above 130 °C to form "capped cluster" intermediates that coalesce into well-defined Co nanoclusters, but are resistant to further aggregation. At the post-nucleation stage, a

SUBMITTER: Chen Z 

PROVIDER: S-EPMC4423618 | biostudies-literature | 2014

REPOSITORIES: biostudies-literature