A general strategy for colloidal stable ultrasmall amorphous mineral clusters in organic solvents

While nature exerts precise control over the size and chemical composition of minerals, this is still a challenging task for artificial syntheses. Despite its significance, until now, there are still no reports on colloidal mineral nanoparticles in the subnanometer range. Here we developed a general gas diffusion strategy using 10,12-pentacosadiynoic acid as a ligand and ethanol as a solvent to fabricate stable amorphous mineral clusters with a core size of less than 2 nm. First discovered for CaCO(3), the method was successfully extended to produce monolayer protected clusters of MgCO(3), SrCO(3), Eu(2)(CO(3))(3), Tb(2)(CO(3))(3), Ce(2)(CO(3))(3), Ca( x )(PO(4))( y ), CaC(2)O(4) and their hybrid minerals, Ca( x )Mg( y )(CO(3))( z ) and Ca( x )(CO(3))( y )(PO(4))( z ). All the mineral clusters can be well dispersed in organic solvents like toluene, and are stable for a long period without further crystallization. Our work paves a way for the artificial synthesis of colloidal mineral clusters, which may have various uses in both fundamental research and industry.