Sequential growth of iridium cluster anions based on simple cubic packing.

Geometric structures of free iridium cluster anions, Irn-, were examined by means of ion mobility mass spectrometry and density functional theory calculation for n = 3-15 with the additional help of photoelectron spectroscopy for n = 4-10. It has been revealed that Irn- clusters with n ≥ 5 favor a square facet and take a cubic motif in contrast to the face-centered cubic structures in the corresponding nanoparticles and bulk. A growth sequence of Irn- for n = 5-15 is proposed: single Ir atoms are sequentially attached to one side of the square plane of Ir4- to form a cubic Ir8-, and are then continuously attached on one of the square facets of Ir8- for n = 9-12 and Ir12- for n = 13-15.

Characterization of chemically modified gold and silver clusters in gas phase.

Atomically precise Au and Ag clusters protected by organic ligands can be viewed as chemically modified Au/Ag superatoms and have attracted interest as promising building units of functional materials and ideal platforms for studying the size-dependent evolution of structures and properties. Their structures, stability, and physicochemical properties have been characterized in solution and solid (or crystalline) phases by various methods conventionally used in materials science. However, novel and complementary information on their intrinsic stability and structures can be obtained by applying a variety of gas-phase methods, including mass spectrometry, ion mobility mass spectrometry, collision- or surface-induced dissociation mass spectrometry, photoelectron spectroscopy, and photodissociation mass spectrometry, to the chemically modified Au/Ag superatoms isolated in the gas phase.

N-heterocyclic carbene-functionalized magic-number gold nanoclusters.

Magic-number gold nanoclusters are atomically precise nanomaterials that have enabled unprecedented insight into structure-property relationships in nanoscience. Thiolates are the most common ligand, binding to the cluster via a staple motif in which only central gold atoms are in the metallic state. The lack of other strongly bound ligands for nanoclusters with different bonding modes has been a significant limitation in the field.

Collision-Induced Dissociation of Undecagold Clusters Protected by Mixed Ligands [Au(PPh)X] (X = Cl, C≡CPh).

We herein investigated collision-induced dissociation (CID) processes of undecagold clusters protected by mixed ligands [Au(PPh)X] (X = Cl, C≡CPh) using mass spectrometry and density functional theory calculations. The results showed that the CID produced fragment ions [Au (PPh) X ] with a formal electron count of eight via sequential loss of PPh ligands and AuX(PPh) units in a competitive manner, indicating that the CID channels are governed by the electronic stability of the fragments. Interestingly, the branching fraction of the loss of the AuX(PPh) units was significantly smaller for X = C≡CPh than that for X = Cl.