Determining the total structure of metal nanoparticles is vital to understand their properties. In this work, the first all-alkynyl-protected Ag nanocluster, Ag(C≡CPh), was synthesized and structurally characterized by single crystal diffraction. Ag atoms are arranged in a Ag@Ag@Ag three shell structure and all 44 phenylethynyl ligands coordinated with Ag in a μ mode. In spite of being absent in nanocluster, P NMR study reveals that bidentate phosphine first reacts with Ag(I) to form a dinuclear complex, from which Ag atoms are then released to phenylethynyl ligands. This phosphine mediated strategy may find general application in synthesis of alkynyl-protected Ag nanoclusters.
The structures and electronic properties of LaSi n − (n = 2−6) anions and their neutral counterparts were investigated by anion photoelectron spectroscopy and theoretical calculations. The vertical detachment energies of the most stable structures of LaSi n − (n = 2−6) were measured to be 1.28, 1.58, 2.30, 2.05, and 2.91 eV, respectively. The lowest-energy isomer of LaSi 2− is an isosceles triangle with a C 2v symmetry. For LaSi 3−6 − clusters, the most stable isomers are polyhedrons with La atom face-capping the Si n frameworks. The lowest-energy structures of neutral LaSi 2,4,5 clusters are similar to their anionic counterparts. The most stable isomer of neutral LaSi 3 is a planar structure with C 2v symmetry, which is different from the triangular pyramid structure of LaSi 3 − anion. The lowest-energy isomer of LaSi 6− is a C 5v symmetric pentagonal bipyramid structure, while for neutral LaSi 6 cluster, the C 5v structure is not the most stable one. The natural population analysis showed that there is electron transfer from La atoms to Si atoms in LaSi n −/0 (n = 2−6). The ZZ tensor component in isochemical shielding surfaces and the anisotropy of the induced current density analyses indicate that the most stable isomer of LaSi 6 − has aromaticity.
The structures and chemical bonding of Ge 3 C − and Ge 3 O − as well as their neutrals are explored with anion photoelectron spectroscopy and theoretical calculations. The vertical detachment energies of Ge 3 C − and Ge 3 O − are measured to be 1.51 ± 0.04 and 2.00 ± 0.04 eV, respectively. It is found that Ge 3 C −/0 have a C 2v symmetric planar structure with the C atom interacting with three Ge atoms. Ge 3 O −/0 have the O atom interacting with two Ge atoms of the triangular Ge 3 unit. Ge 3 O − has a C s symmetric nonplanar structure, while Ge 3 O has a C 2v symmetric planar structure. Theoretical results show that the multiconfigurational effects in Ge 3 C −/0 and Ge 3 O −/0 are insignificant. Chemical bonding analyses reveal that there exist the C−Ge 3 π ⊥ orbital interaction and two π aromatic Ge 2 C units in Ge 3 C. There are O−Ge 3 π ⊥ orbital interaction and one doubly aromatic Ge 3 unit in Ge 3 O, but the π ⊥ orbital interaction is relatively weak.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.