Diphosphine-Stabilized Small Gold Nanoclusters: From Crystal Structure Determination to Ligation-Driven Symmetry Breaking and Anion Exchange Properties

A new
class of small gold nanoclusters with molecular characteristics
has been constructed using 1,1′-bis­(diphenyl­phosphino)­ferrocene
(dppf) as the stabilizing ligand. The identities of the small gold
nanoclusters have been fully characterized by NMR, electrospray ionization
mass spectrometry, elemental analysis, and single-crystal X-ray diffraction
analysis. Octa- and undeca­gold clusters are found to display
different UV–vis absorption behavior. The ligation of the bidentate
ligands and halides or pseudo­halides has resulted in the symmetry
breaking of these nanoclusters with C1 symmetry. The small gold nanoclusters with different coordinating
halides or pseudo­halides show distinct reactivities and stabilities
in ligand/anion exchange experiments. The current research has provided
insights into the origin of chirality in the diphosphine-stabilized
small gold nanoclusters.