Structural and bonding properties of Cu3O3- and Cu3O4- clusters: anion photoelectron spectroscopy and density functional calculations

Anion Photoelectron Spectroscopy and Quantum Chemical Calculations of Bimetallic Oxide Clusters YCu2On-/0 (n = 2-5)

The structural and electronic properties of bimetallic oxide clusters, YCu₂O_n^- and YCu₂O_n (n = 2-5), are investigated using anion photoelectron spectroscopy and density functional theory calculations. The experimental vertical detachment energies of YCu₂O₂^-, YCu₂O₃^-, YCu₂O₄^-, and YCu₂O₅^- were measured to be 1.59, 1.76, 3.85, and 3.78 eV, respectively. Vibrationally resolved photoelectron spectra have been obtained for YCu₂O₂^-, with a spacing of 726 ± 80 cm^-1 assigned to the Y-O stretching vibrational mode. It is found that YCu₂O₂^- and YCu₂O₂ have C_2v symmetric planar five-membered ring structures. YCu₂O₃^- and YCu₂O₃ have C_2v symmetric planar six-membered ring structures. The most stable structure of YCu₂O₄^- is a quasi-planar structure which can be viewed as one O atom interacting with the Y atom of the YCu₂O₃ six-membered ring, while the most stable structure of YCu₂O₄ is a planar seven-membered ring. YCu₂O₅^- and YCu₂O₅ have nonplanar structures, which can be viewed as an O₂ unit interacting with the Y atom of the YCu₂O₃ six-membered ring. In YCu₂O_3,4,5^-/0, the Y-O and Cu-O bonds are dominant, while the Y-Cu and Cu-Cu interactions are weak.

Anion Photoelectron Spectroscopy and Theoretical Studies of Al4C6-/0: Global Minimum Triangle-Shaped Structures and Hexacoordinated Aluminum

Anion photoelectron spectroscopy and theoretical calculations were used to investigate the structural and bonding properties of Al₄C₆^-/0 clusters. The vertical detachment energy of Al₄C₆^- was measured to be 3.36 ± 0.08 eV. The structure of the Al₄C₆^- anion is confirmed to be a bowl-shaped distorted triangle with an Al atom at the center and three Al atoms at the vertices. The global minimum isomer of neutral Al₄C₆ has a planar triangle-shaped structure with D_3h symmetry. Both anionic and neutral Al₄C₆ have a hexacoordinated Al atom surrounded by three C≡C groups. Compared with the structure of neutral Al₄C₆, the structure of Al₄C₆^- is distorted due to the addition of the excess electron. The molecular orbital analysis shows that the singly occupied molecular orbital of Al₄C₆^- mainly locates on one side of the triangle plane and the neutral Al₄C₆ has a large highest occupied molecular orbital and lowest unoccupied molecular orbital gap. Theoretical calculations indicate that neutral Al₄C₆ has some aromaticity.