Magnetically induced currents and aromaticity in ligand-stabilized Au and AuPt superatoms.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 33931646.
- Also identified by DOI 10.1038/s41467-021-22715-x and PMC identifier 8087673.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Understanding magnetically induced currents (MICs) in aromatic or metallic nanostructures is crucial for interpreting local magnetic shielding and NMR data. Direct measurements of the induced currents have been successful only in a few planar molecules but their indirect effects are seen in NMR shifts of probe nuclei. Here, we have implemented a numerically efficient method to calculate gauge-including MICs in the formalism of auxiliary density functional theory. We analyze the currents in two experimentally synthesized gold-based, hydrogen-containing ligand-stabilized nanoclusters [HAu<sub>9</sub>(PPh<sub>3</sub>)<sub>8</sub>]<sup>2+</sup> and [PtHAu<sub>8</sub>(PPh<sub>3</sub>)<sub>8</sub>]<sup>+</sup>. Both clusters have a similar octet configuration of Au(6s)-derived delocalized "superatomic" electrons. Surprisingly, Pt-doping in gold increases the diatropic response of the superatomic electrons to an external magnetic field and enhances the aromaticity of [PtHAu<sub>8</sub>(PPh<sub>3</sub>)<sub>8</sub>]<sup>+</sup>. This is manifested by a stronger shielding of the hydrogen proton in the metal core of the cluster as compared to [HAu<sub>9</sub>(PPh<sub>3</sub>)<sub>8</sub>]<sup>2+</sup>, causing a significant upfield shift in agreement with experimental proton NMR data measured for these two clusters. Our method allows the determination of local magnetic shielding properties for any component in large 3D nanostructures, opening the door for detailed interpretation of complex NMR spectra.