Controlling Chirality and Stability of Gold Nanoclusters by PNP Pincer Ligand Diastereomers

The emerging metal nanoclusters with atomically precise structures have gained considerable attention because they exhibit promising applications in various fields and serve as ideal models for studying the structure-property correlation of nanoparticles. Despite significant advances, it is still unclear how ligand diastereomers impact the stability and chirality of metal nanoclusters. In this work, we systematically studied the construction of gold nanoclusters using the PNP (PNP = 2,6-bis(1-(diphenylphosphaneyl)ethyl)pyridine) pincer ligand consisting of multiple stereoisomers. A metastable Au₆ skeleton was found to be a key intermediate, which can be controlled in the aspects of stability and chirality by the PNP ligand diastereomers to selectively produce Au₉(R,R-PNP)₄, Au₉(S,S-PNP)₄, Au₉(R,S-PNP)₄, Au₆(R,S-PNP)₂(R,R-PNP), and Au₆(R,S-PNP)₂(S,S-PNP) nanoclusters with intriguing properties such as self-sorting and spontaneous resolution. This work provides a strategy for regulating the stability and chirality of metal nanoclusters by ligand diastereomers.