DFT calculations for aerobic oxidation of alcohols over neutral Au6cluster

Probing the structural, electronic, and adsorptive properties of Au16O2- clusters

Great progress has been made in O₂ adsorption on gold clusters. However, systematic investigations of O₂ adsorption on [Formula: see text] clusters have not been reported. Here, we present a systematic study of the structural, electronic, and adsorptive properties of [Formula: see text] clusters by density functional theory (DFT) calculations coupled with stochastic kicking method. Global minimum searches for [Formula: see text] reveal that exohedral derivatives are more favored. Furthermore, the obtained ground-state structure exhibits significant stability, as judged by its larger adsorption energy (1.16 eV) and a larger HOMO-LUMO gap (0.57 eV). The simulated photoelectron spectra (PES) of [Formula: see text] isomers will be instructive to identify the structures in future experiments. There are three interesting discoveries in the present paper: (1) O₂ undergoes chemical adsorption onto the parent [Formula: see text] clusters, but the amount of the adsorption energy is related to the parent [Formula: see text] clusters; (2) the process that O₂ undergoes dissociative adsorption onto the parent [Formula: see text] clusters is exothermic; (3) [Formula: see text] isomers show smaller X-A energy gaps than those of parent [Formula: see text] clusters, reflecting that their geometric and electronic structures are distorted remarkably due to dissociative adsorption of O₂.

Probing the Hydrogen Bonding in Microsolvated Clusters of Au1,2-(Solv)n (Solv = C2H5OH, n-C3H7OH; n = 1-3 for Au-; n =1 for Au2-)

The microsolvation of gold anions in different alcohol solvents is demonstrated by the combination of anion photoelectron spectroscopy and quantum chemical calculations on the Au_1,2^-(Solv)_n (Solv = C₂H₅OH, n-C₃H₇OH; n = 1-3 for Au^-; n = 1 for Au₂^-). The microsolvation structures of these clusters and their corresponding neutrals are assigned by comparing calculations with experiments. In terms of overall regularity, the increasing solvation number (n) and carbon chain extension both can increase the stability of the anion. When n ≥ 2, these clusters have low-energy isomers, where conventional hydrogen bonds (HBs) compete with nonconventional HBs (NHBs). NHBs are dominant when n ≤ 2 and when n is increased, vice versa. Interestingly, a variety of theoretical calculations show that after the hydroxy H atom of the ethanol molecule forms a weak ionic HB with Au^-, there are two lowest conformations of ethanol, trans and gauche, which could be coexisting in the molecular beams. Some theoretical methods also suggest that the gauche isomer is more stable than the trans one, which indicates that Au^- may exist as a gold gauche effect similar to fluorine.