A New Type of Terpene-Based D-2-Symmetric Macrocycles, Capable of Selectively Extracting Au, Pd and Pt from Complex Mixtures

摘要

C-2-symmetric terpene-based bis(alpha-amine oximes) prepared from monoterpene hydrocarbons (+)-3-carene, (-)-alpha-pinene and (+)-limonene, when treated with methylene chloride under phase-transfer conditions, undergo inter- and intramolecular cross-linking at oxime groups to form D-2-symmetric macrocycles in relatively good preparative yields (35-64 ). The structure of the new compounds was solved by spectroscopic methods and proved by X-ray crystallography. D-2-symmetric macrocycles are crystalline solids which are well soluble even in small amounts of low-polar organic solvents. Using Microwave Plasma Atomic Emission Spectrometry the new compounds was found to be able to selectively extract some noble metals (Pt-IV, Au-III, Pd-II) from aqueous solutions with pH=1.2 containing complex mixtures of transition elements at with no noticeable extraction of d-elements (Cr-VI, Mn-II, Fe-III, Co-II, Ni-II, Cu-II, Zn-II) and other noble metals (Ru-III, Rh-III, Ir-III).