Photoluminescence of Doped Superatoms M@Au<sub>12</sub> (M = Ru, Rh, Ir) Homoleptically Capped by (Ph<sub>2</sub>)PCH<sub>2</sub>P(Ph<sub>2</sub>): Efficient Room-Temperature Phosphorescence from Ru@Au<sub>12</sub>
Shinjiro Takano, Haru Hirai, Takuya Nakashima, Takeshi Iwasa, Tetsuya Taketsugu, Tatsuya Tsukuda
Abstract
A series of doped gold superatoms M@Au12 (M = Ru, Rh, Ir) was synthesized by capping with the bidentate ligand (Ph2)PCH2P(Ph2). A single-crystal X-ray diffraction analysis showed that all the M@Au12 superatoms had icosahedral motifs with a significantly higher symmetry than that of the pure Au13 counterpart due to different coordination geometries. The Ru@Au12 superatom exhibited a room-temperature phosphorescence with the highest quantum yield of 0.37 in deaerated dichloromethane. Density functional theory calculations suggested that the efficient phosphorescence is ascribed to a rapid intersystem crossing due to the similarity between the singlet and triplet excited states in terms of structure and energy.