The title question is motivated by the fact that extremely small thiolated-gold clusters such as Au20(SR)16 have been isolated, but their undetermined structures cannot be fully rationalized by the present knowledge derived from single-crystal structures of larger clusters. One needs to go beyond the linear monomer (RSAuSR) and V-shaped dimer (RSAuSRAuSR) motifs that were found to protect larger clusters. We hypothesize that the U-shaped trimer motif (RSAuSRAuSRAuSR) is required to protect the core of some extremely small thiolated-gold clusters, which have about 20 or fewer Au atoms. We test this hypothesis by proposing structural models for Au 10(SR)8 based on two trimer motifs protecting a tetrahedral Au4 core and for Au20(SR)16 based on four trimer motifs protecting an Au8 core.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Physical and Theoretical Chemistry
- Surfaces, Coatings and Films