Tailoring Vacancy Defects in Isolated Atomically Precise Silver Clusters through Mercury-Doped Intermediates

Vacancy defects are known to have significant effects on the physical and chemical properties of nanomaterials. However, the formation and structural dynamics of vacancy defects in atomically precise coinage metal clusters have hardly been explored due to the challenges associated with isolation of such defected clusters. Herein, we isolate [Ag28(BDT)12]2– (BDT is 1,3-benzenedithiol), a cluster with a “missing atom” site compared to [Ag29(BDT)12]3–, whose precise structure is known from X-ray diffraction. [Ag28(BDT)12]2– was formed in the gas-phase by collisional heating of [Ag28Hg(BDT)12]2–, a Hg-doped analogue of the parent cluster. The structural changes resulting from the loss of the Hg heteroatom were investigated by trapped ion mobility mass spectrometry. Density functional theory calculations were performed to provide further insights into the defect structures, and molecular dynamics simulations revealed defect site-dependent structural relaxation processes.