The fluorescence properties of tiara like structural thiolated palladium clusters

Abstract

A series of tiara like structural Pd_n(SR)_2n (5 ≤ n ≤ 20) nanoclusters were synthesized by using a modified Brust–Schiffrin route and isolated via thin layer chromatography, and further measured using MALDI-MS. A new crystal structure of tiara like structural Pd₆(SC₂H₄Ph)₁₂ was determined by single-crystal X-ray crystallography. The atomic distance of Pd⋯Pd increased and the Pd–S bond length decreased with the increase in the n value in the optimized structure of Pd_n(SR)_2n (5 ≤ n ≤ 10), which were optimized by density functional theory at the B3LYP level. All these 16 Pd_n(SR)_2n nanoclusters exhibit weak emission at 620 nm with single band excitation at around 268 nm. The origin of emission of this series of clusters could be illustrated by using a ligand to metal charge transfer model.