Argon tagging of doubly transition metal doped aluminum clusters: The importance of electronic shielding

Abstract

The interaction of argon with doubly transition metal doped aluminum clusters, Al n TM 2 + (n = 1 -18, TM = V, Nb, Co, Rh), is studied experimentally in the gas phase via mass spectrometry. Density functional theory calculations on selected sizes are used to understand the argon affinity of the clusters, which differ depending on the transition metal dopant. The analysis is focused on two pairs of consecutive sizes: Al 6,7 V 2 + and Al 4,5 Rh 2 + , the largest of each pair showing a low affinity toward Ar. Another remarkable observation is a pronounced drop in reactivity at n = 14, independent on the dopant element. Analysis of the cluster orbitals shows that this feature is not a consequence of cage formation but is electronic in nature. The mass spectra demonstrate a high similarity between the size-dependent reactivity of the clusters with Ar and H 2 . Orbital interactions provide an intuitive link between the two and further establish the importance of precursor states in the reactions of the clusters with hydrogen.

Hydride Locations and Planar σ‐Aromaticity in Hydrido‐Coinage‐Metal Clusters

“…It should be pointed out that such functional based on this basis set is demonstrated to be reliable and widely used to determine configurations of binary clusters. [42,43] The Figure S1 presents the benchmark calculation results for DFT/Def2-TZVP and CCSD(T)/Def2-TZVP. The gaps in relative energies for three Cu 5 H isomers optimized using the PBE functional are in excellent agreement with those obtained from the CCSD(T) method.…”

“…Using the GA‐DFT method, we first identified the ground states and isomeric structures of M n H (M=Cu, Ag and Au; n =2–9) clusters at the PBE/Def2‐TZVP level. It should be pointed out that such functional based on this basis set is demonstrated to be reliable and widely used to determine configurations of binary clusters [42,43] . The Figure S1 presents the benchmark calculation results for DFT/Def2‐TZVP and CCSD(T)/Def2‐TZVP.…”