Au₂₄(SAdm)₁₆ nanomolecules: X-ray crystal structure, theoretical analysis, adaptability of adamantane ligands to form Au₂₃(SAdm)₁₆ and Au₂₅(SAdm)₁₆, and its relation to Au₂₅(SR)₁₈

J Am Chem Soc. 2014 Oct 22;136(42):14933-40. doi: 10.1021/ja507738e. Epub 2014 Oct 13.

Abstract

Here we present the crystal structure, experimental and theoretical characterization of a Au24(SAdm)16 nanomolecule. The composition was verified by X-ray crystallography and mass spectrometry, and its optical and electronic properties were investigated via experiments and first-principles calculations. Most importantly, the focus of this work is to demonstrate how the use of bulky thiolate ligands, such as adamantanethiol, versus the commonly studied phenylethanethiolate ligands leads to a great structural flexibility, where the metal core changes its shape from five-fold to crystalline-like motifs and can adapt to the formation of Au(24±1)(SAdm)16, namely, Au23(SAdm)16, Au24(SAdm)16, and Au25(SAdm)16. The basis for the construction of a thermodynamic phase diagram of Au nanomolecules in terms of ligands and solvent features is also outlined.