Surface-Induced Isomerization in [PtAg₂₀{S₂P(OR)₂}₁₂] (R = ⁿPr, ⁱPr, ⁱBu) Nanoclusters: Unveiling Shell Variability through X-ray Diffraction

Abstract

We present the synthesis and structural characterization of four distinct crystal structures, [PtAg20{S2P(O n Pr)2}12]0.4[Ag20{S2P(O n Pr)2}12]0.6 (1), [PtAg20{S2P(O n Pr)2}12]0.25[Ag20{S2P(O n Pr)2}12]0.75 (2), [PtAg20{S2P(O i Pr)2}12] (3), and [PtAg20{S2P(O i Bu)2}12] (4), utilizing two primary synthetic routes: galvanic replacement and coreduction. Despite different synthetic approaches, the PtAg20 skeleton exhibited variations in symmetry, primarily due to the different arrangements of capping silver atoms. Positive-ion ESI-MS verified the composition, aligning well with theoretical calculations. Notably, the surface of these NCs demonstrates fluxional properties, suggesting rapid and dynamic changes in solution. Variable-temperature 31P{1H} NMR experiments provided insights into the fluxional nature of the NC surface and the potential for symmetry transformations in solution.