The location of the Pd atoms in Pd₂Au₃₆(SC₂H₄Ph)₂₄, is studied both experimentally and theoretically. X-ray photoelectron spectroscopy (XPS) indicates oxidized Pd atoms. Palladium K-edge extended X-ray absorption fine-structure (EXAFS) data clearly show Pd-S bonds, which is supported by far infrared spectroscopy. By comparing theoretical EXAFS spectra in R space and circular dichroism spectra of the staple, surface and core doped structures with experimental spectra.

The Au₁₀₂(p-MBA)₄₄ cluster (p-MBA: para-mercaptobenzoic acid) is observed as a chiral compound comprised of achiral components in its single-crystal structure. So far the enantiomers observed in the crystal structure are not isolated, nor is the circular dichroism spectrum known. A chiral phase transfer method is presented which allows partial resolution of the enantiomers by the use of a chiral ammonium bromide, (−)-1R,2S-N-dodecyl-N-methylephedrinium bromide ((−)-DMEBr). At sufficiently low concentration of (−)-DMEBr, the phase transfer from water to chloroform is incomplete. Both the aqueous and organic phases show optical activity of near mirror image relationship. Differences in the spectra are ascribed to the formation of diastereomeric salts. At high concentrations of (−)-DMEBr, full phase transfer is observed. The organic phase, however, still displays optical activity. We assume that one of the diastereomers has very strong optical activity, which overrules the cancelation of the spectra with opposite sign. Comparison with computations further corroborates the experimental data and allows a provisional assignment of handedness of each fraction.

The recently reported crystal structure of the Au₂₈(TBBT)₂₀ cluster (TBBT: para-tert-butylbenzenethiolate) is analyzed with (Time-Dependent-) Density Functional Theory (TD-DFT). Bader charge analysis reveals a novel trimeric Au₃(SR)₄ binding motif. The cluster can be formulated as Au₁₄(Au2(SR)₃)₄(Au₃(SR)₄)₂. The electronic structure of the Au146+ core and the ligand-protected cluster were analyzed and their stability can be explained by formation of distorted eight-electron superatoms. Optical absorption and Circular Dichroism (CD) spectra were calculated and compared to the experiment. Assignment of handedness of the intrinsically chiral cluster is possible.

We predict and analyze density-functional theory (DFT) -based structures for the recently isolated Au₄₀(SR)₂₄ cluster. Combining structural information extracted from ligand-exchange reactions, circular dichroism and transmission electron microscopy leads us to propose two families of low-energy structures that have a chiral Au-S framework on the surface. These families have a common geometrical motif where a non-chiral Au₂₆ bi-icosahedral cluster core is protected by 6 RS-Au-SR and 4 RS-Au-SR-Au-SR oligomeric units, analogously to the “Divide and Protectâ€� motif of known clusters Au₂₅(SR)18^-/0, Au₃₈(SR)₂₄ and Au₁₀₂(SR)₄₄. The strongly prolate shape of the proposed Au₂₆ core is supported by transmission electron microscopy. Density-of-state-analysis shows that the electronic structure of Au₄₀(SR)₂₄ can be interpreted in terms of a dimer of two 8-electron superatoms, where the 8 shell electrons are localized at the two icosahedral halves of the metal core. The calculated optical and chiroptical characteristics of the optimal chiral structure are in a fair agreement with the reported data for Au₄₀(SR)₂₄.