Structure-conserving spontaneous transformations between nanoparticles.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 27830711.
- Also identified by DOI 10.1038/ncomms13447 and PMC identifier 5110647.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Ambient, structure- and topology-preserving chemical reactions between two archetypal nanoparticles, Ag<sub>25</sub>(SR)<sub>18</sub> and Au<sub>25</sub>(SR)<sub>18</sub>, are presented. Despite their geometric robustness and electronic stability, reactions between them in solution produce alloys, Ag<sub>m</sub>Au<sub>n</sub>(SR)<sub>18</sub> (m+n=25), keeping their M<sub>25</sub>(SR)<sub>18</sub> composition, structure and topology intact. We demonstrate that a mixture of Ag<sub>25</sub>(SR)<sub>18</sub> and Au<sub>25</sub>(SR)<sub>18</sub> can be transformed to any arbitrary alloy composition, Ag<sub>m</sub>Au<sub>n</sub>(SR)<sub>18</sub> (n=1-24), merely by controlling the reactant compositions. We capture one of the earliest events of the process, namely the formation of the dianionic adduct, (Ag<sub>25</sub>Au<sub>25</sub>(SR)<sub>36</sub>)<sup>2-</sup>, by electrospray ionization mass spectrometry. Molecular docking simulations and density functional theory (DFT) calculations also suggest that metal atom exchanges occur through the formation of an adduct between the two clusters. DFT calculations further confirm that metal atom exchanges are thermodynamically feasible. Such isomorphous transformations between nanoparticles imply that microscopic pieces of matter can be transformed completely to chemically different entities, preserving their structures, at least in the nanometric regime.