Stabilization of a new nanocomposite family by reduction of gold nanoclusters with electron-reservoir complexes

Four stable 19-electron Fe and Co sandwich electron-reservoirs and three hydride reservoir complexes reduce the prototypal nanocluster Au 25 (SR) 18 (R = CH 2 CH 2 Ph) leading to a largely increased kinetic stabilization of the anionic nanocluster form compared to previously known nanocluster anion salts; these salts represent new and robust nanocomposite anionic gold clusters with 18-electron sandwich complexes as counter cations. The aerobic stabilities of four new Au 25 nanocluster-metal sandwich composites are provided by and related to the metal-sandwich ring sizes.