Adsorption of multiple NO molecules on Au 10 - and Au 9 Zn - planar clusters. A comparative DFT study.

The doping of atomic clusters with transition-metal atoms modifies to a lesser or greater extent the catalytic properties of the pure forms. Here we study by means of density functional theory (DFT) the adsorption of up to six NO molecules on Au 10 - and Au 9 Zn - clusters, both with well-tested D 3h planar geometry, to learn how precise modifications of the atomic and electronic environment, namely one atom and a valence electron, affect the bonding of multiple NO molecules to anionic gold clusters. First, we confirm that these clusters have D 3h symmetry as determined by L. S. Wang and coworkers using photoelectron spectroscopy experiments [Kulichenko et al. , J. Phys. Chem. A , 2021, 125 , 4606]. Second, we verify that Au 10 (NO) n - with n ≤ 6 does not form adsorbed (NO) 2 dimers, as realized by the experiments of Ma and coworkers [Ma et al. , Phys. Chem. Chem. Phys. , 2020, 22 , 25227] using a mini flow-tube reactor at 150 K. Third, we discover that the ground state of the doped Au 9 Zn(NO) 6 - compound forms a (NO) 2 cis -dimer bridging two non-corner Au atoms of the Au 9 Zn(NO) 4 - compound. The discussion of adsorption energies, spin multiplicities, bond lengths, charge trends, vibrational strength frequencies of adsorbed NO's, and projected density of states (PDOS), brings additional testable differences between Au 10 (NO) n - and Au 9 Zn(NO) n - compounds ( n ≤ 6).