A 36-Nucleus Silver-Thiolate Cluster Encapsulating Double Sulfates and Co-Protected by Cyclen

Abstract

New type of cyclic multi-dentate ligand named, Cyclen (1,4,7,10-tetraazacyclododecane, [12]aneN4), was successfully introduced onto the surface of a 36-nucleus double sulfates templated silver-thiolate cluster [(SO4)2@Ag36(SPhtBu)24(cyclen)4(CF3CO2)6(OH)2] (1). The nanocluster was investigated and characterized by single-crystal X-ray crystallography (SXRD), infrared spectroscopy (IR), X-ray photoelectron spectroscopy (XPS), thermogravimetry (TG), ultraviolet−visible (UV) spectroscopy, and photoluminescence (PL). The cluster shows very good solution stability in four different solvents and excellent thermal stability in the solid-state. It shows orange-red emission in EtOAc/THF/CH2Cl2/CHCl3 at 77 K. The lifetime of 1 in four different solvents is over 140 μs, and the highest quantum yield of 1 is 25.46 %. The nanocluster shows temperature-dependent photoluminescence properties in different solvents, which make them potential candidates in the fields of optical devices for future applications.

Keywords: Coinage metal nanoclusters, Sliver cluster, Surface functional ligands, Photoluminescence