Direct Observation of Three Chiral Conformers of an Atomically Precise Metal Nanoparticle

Atomically precise metal nanoclusters
(NCs) have attracted a lot
of attention owing to their many interesting properties and applications.
On the fundamental side, they can provide a testbed for understanding
structure–property relationships in nanomaterials. Hence, their
isomerism is of intrinsic significance. In this work, we report the
atomically precise structure of three Cu14 NC conformers,
i.e., NCs with the same chemical formula and atomic connectivity but
with varying bond angles and distances, obtained through X-ray crystallography.
Interestingly, all three conformers exhibit chirality and cocrystallize
in the same lattice structure. Since interconversion of each conformer
and its chiral counterpart is possible without breaking and remaking
bonds, these NCs constitute a set of atrop­isomers. The structure
of our Cu14 NC highlights the various sources of isomerism
one can observe at the nanoscale. These subtle yet identifiable differences
represent something like a minimal unit of structural change, facilitating
future investigation of structure–property relationships.