Search

The first mixed-valence nanocluster Cu I /Cu II with the highest percentage of Cu II ions was synthesized by using 4- tert -butylcalix[4]arene (Calix4), with the formula DMF 2 ⊂[(CO 3 ) 2- @Cu II 6 Cu I 3 (Calix4) 3 Cl 2 (DMF) 5 (H 3 O)]•DMF ( 1 ), as a photothermal nanocluster. Its structure was characterized using single-crystal X-ray diffraction, Fourier-transform infrared spectroscopy, and powder X-ray diffraction. In addition, the charge state and chemical composition of the nanocluster were determined using electrospray ionization spectrometry and X-ray photoelectron spectroscopy (XPS) spectrum. The results of the XPS and X-ray crystallography revealed that there are two independent Cu II and Cu I centers in nanocluster 1 with the relative abundances of 66.6 and 33.3% for Cu II and Cu I , respectively. The nanocluster contains three four-coordinated Cu I ions with a square-planar geometry and six five-coordinated Cu II ions with a square pyramid geometry. The nanocluster shows strong near-infrared optical absorption in the solid state and excellent photothermal conversion ability (the equilibrium temperature ∼78.2 °C) with the light absorption centers in 286-917 nm over previous reported pentanucleus Cu I 4 Cu II clusters and Cu II compounds.

A pair of enantiopure Au 13 nanoclusters have been enantioselectively synthesized by chiral ligands with stereogenic centers at the phosphorus atoms. Their structures are determined by X-ray crystallography, which are typical models with a high symmetric core and chiral surface ligand arrangement. Correlation between the crystallographic structure, the calculation, and the circular dichroism (CD) study indicates that helical ligand arrangement inducing the core into chiral distortion accounts for the chiroptical activities in the visible region. A rare example of cocrystallization of a mixture of diastereomers has been observed for the first time for gold nanoclusters, reflecting the lack of chiral self-sorting of the ligands.