Application of crown compounds bearing photochromic moiety for metal ion separation and determination

Abstract

Organic compounds, whose structure and absorption spectrum are changed by photoirradiation with a particular wavelength and vise versa by the other light irradiation, are called photochromic. The metal-ion complexing abilities and selectivities of several crown ether derivatives bearing photochromic moiety have been so far investigated under photoirradiation conditions, and remarkable changes in their properties were often realized. Several compounds, such as crowned photochromic compounds, are isomerized and their absorption spectra are simultaneously changed by metal ion complexation even under dark conditions. In this paper, quantitative evaluation of metal-ion complexing abilities of crowned photochromic compounds caused by photoirradiation with electrospray ionization mass spectrometry (ESI-MS) was described. Liquid-liquid extraction and liquid membrane transport using photochromic crown compounds with photoirradiation were also shown as metal-ion separation methods. Absorption spectral changes with metal ion complexation of photochromic crown compounds were applied to metal ion determination using liquid-liquid extraction and micelles containing them.