Chemical characterization, absolute configuration and optical purity of (1S)-(+)- and (1R)-(-)-10-camphorsulfonic acid.

Comprehensive chemical characterization for two isomers of camphorsulfonic acid (CSA), occasionally used in the manufacture of active pharmaceutical ingredients (APIs), was performed by nuclear magnetic resonance (NMR) spectroscopy, high-resolution mass spectroscopy in negative electrospray ionization mode and gas chromatography/mass spectrometry (GC/MS) in electron ionization mode. Electronic circular dichroism (ECD) spectra together with quantum chemical calculations using time-dependent density functional theory (TD-DFT) were used to assign the stereochemistry for CSA for the first time and these assignments were then confirmed by single-crystal X-ray diffraction. As crystals were grown under the same conditions of high supersaturation using a mixed solvent without water removal, the crystal structures of the two enantiomers contained one ordered molecule of water in the asymmetric unit.

Enhanced dark adsorption and visible-light-driven photocatalytic properties of narrower-band-gap CuS decorated CuO nanocomposites for efficient removal of organic pollutants.

The CuS-decorated CuO nanocomposites were synthesized by a facile co-precipitation and calcination method, and used as adsorbent and photocatalyst to remove organic pollutants from wastewater. Batch adsorption experiments were conducted to investigate the influences of molar ratio of CuO to CuS, initial solution pH, coexisting anion and temperature on the adsorption performances. As-obtained CuO/CuS-9/1 nanocomposite with high specific surface area (45.