Contacted Ion Pairs in Aqueous CuCl₂ by the Combination of Ratio Spectra, Difference Spectra, Second Order Difference Spectra in the UV-Visible Spectra

Abstract

The microstructure of aqueous CuCl 2 has been studied through lots of technologies for many years; however, it remains a controversial subject. In this study, a new spectroscopic method has been proposed to analyze the UV-visible spectra of thin film of CuCl 2 /H 2 O solutions at different concentrations. This method is the combination of ratio spectra, difference spectra and second order difference spectra. By using this method, two new bands at ∼230 and ∼380 nm are obviously observed. The bands are assigned as the contacted ion pairs [CuCl 3 (H 2 O) n ] − or [CuCl 4 (H 2 O) n ] 2− , which demonstrates that ion pairs exist in the CuCl 2 /H 2 O solution. Such finding agrees with the recent theoretical spectra obtained by time-dependent density functional theory. Furthermore, the populations of the contacted ion pairs are discussed. This study not only offers the direct spectroscopic evidence of [CuCl 3 (H 2 O) n ] − or [CuCl 4 (H 2 O) n ] 2− in aqueous CuCl 2 , but also suggests that the spectroscopic analysis method is powerful to extract the weak bands in a strong overlapping spectrum.

The Effect of Disulfiram and Copper on Cellular Viability, ER Stress and ALDH Expression of Human Meningioma Cells

“…First, we conducted the UV-Vis spectral analysis of CuCl 1 mM and CuCl 2 1 mM in an aqueous solution. As shown in Figure 3a, the absorbance spectra of CuCl and CuCl 2 were 260~280 nm and 190~200 nm, separately [46,47]. Then, we treated MgACs and MgSCs for 48 h with DSF/CuCl, DSF/CuCl 2 , or DSF/CuSO 4 .…”