Optical-Response Extraction of Au(III) with Bis(2,2′-dipyridyl-6-yl)diazene and Octanoic Acid

抄録

The optical-response extraction of Au(III) with an azo compound, bis(2,2′-dipyridyl-6-yl)diazene (BDPDA), was studied. The distribution ratio of Au was increased by the configuration change of BDPDA from trans to cis under UV irradiation (340 nm); however, the distribution ratios under UV irradiation were less than 3 times those under VIS irradiation (465 nm). For further improvement of optical-response extraction, the synergistic extraction of Au using octanoic acid as a synergist was tested. Octanoic acid was coordinated mainly with the complex of Au and cis-BDPDA, and effectively enhanced the hydrophobicity of the complex. The distribution ratio of Au under the UV irradiation increased with increasing the concentration of octanoic acid in the organic phase. In the presence of 3 mol/L octanoic acid, the distribution ratio under the UV irradiation reached up to 10 times that under the VIS irradiation.