The NHR_2/CO_2 system as a metal ion extraction reaction reagent from aqueous solution into hydrocarbons: copper(II) and zinc(II)

摘要

A substantially quantitative transfer of copper(II) or zinc(II) salts from aqueous solution into a hydrocarbon (Heptane or toluene) promptly occurs under carbon dioxide in the presence of a dialkylamine (NHR_2, R = Bu, Bz). Recovery of the metal complexes from the organic phase affords copper dialkylcarbamates of the formula Cu(O_2CNR_2)_2(NHR_2)_2 or #mu#-oxo tetranuclear zinc carbamato complexes, Zn_4(#mu#_4-O)(O_2CNR_2)_6, respectively, in high yield and purity. An X-ray diffraction study on a single crystal of Cu(O_2CNBz_2)_2(NHBz_2)_2 1 has shown the compound to be mononuclear with tetracoordinated copper in an almost perfect square-planar geometry. The zinc derivative has the well-established oxo-centred tetranuclear structure (R = Bu, 2).