Alternating Array Stacking of Ag26Au and Ag24Au Nanoclusters

An assembly strategy for metal nanoclusters using electrostatic interactions with weak interactions, such as C−H⋅⋅⋅π and π⋅⋅⋅π interactions in which cationic [Ag26Au(2‐EBT)18(PPh3)6]+ and anionic [Ag24Au(2‐EBT)18]− nanoclusters gather and assemble in an unusual alternating array stacking structure is presented. [Ag26Au(2‐EBT)18(PPh3)6]+ [Ag24Au(2‐EBT)18]− is a new compound type, a double nanocluster ion compound (DNIC). A single nanocluster ion compound (SNIC) [PPh4]+ [Ag24Au(2‐EBT)18]− was also synthesized, having a k‐vector‐differential crystallographic arrangement. [PPh4]+ [Ag24Au(2,4‐DMBT)18]− adopts a different assembly mode from both [Ag26Au(2‐EBT)18(PPh3)6]+ [Ag24Au(2‐EBT)18]− and [PPh4]+ [Ag24Au(2‐EBT)18]−. Thus, the striking packing differences of [Ag26Au(2‐EBT)18(PPh3)6]+ [Ag24Au(2‐EBT)18]−, [PPh4]+ [Ag24Au(2‐EBT)18]− and the existing [PPh4]+ [Ag24Au(2,4‐DMBT)18]− from each other indicate the notable influence of ligands and counterions on the self‐assembly of nanoclusters. A double nanocluster ion compound (DNIC) was synthesized that has a unique alternating stacking array of the cationic and anionic nanoclusters. A single nanocluster ion compound (SNIC), exhibiting a k‐vector‐differential crystallographic arrangement, was also obtained. The notable packing differences among the DNIC and the new and the existing SNICs indicate the dramatic influence of ligands and counterions on crystallographic arrangement.