Crown Ethers in Extraction and Sorption. I. Bromо Derivatives of Benzo- and Dibenzocrown Ethers in the Sorption Processes of Elements from Acidic Water Solutions

Abstract

For the first time the reaction ability of bromoderivatives of benzoand dibenzocrown ethers at sorption of ~30 elements from the water solutions of nitric and muriatic acids was studied. It was found, that an introduction of one (in the case of benzocrown ethers) or two (dibenzocrown ethers) bromine atoms into the phenylene rings of macrocycle increases the sorption properties of the aimed bromides in comparison with the corresponding unsubstituted crown ethers. In this case the properties of dibenzocrown ethers differ rather strongly. So, 4’,4’’,(5’’)-dibromo[3.3]dibenzo18-crown-6 has low level of activity, but in going from [4.4]dibenzo-24-crown-8 to its 4’,4’’,(5’’)-dibromoderivative the sorption properties when extracting some elements from water solutions of hydrochloric acid increase in hundreds of times. Thus, a new highly selective agent for the extraction and separation of elements from multicomponent mixtures was found. Despite rather close spatial and electronic parameters, the reaction ability of 4’,4’’,(5’’)-dibromoand 4’,4’’,(5’’)-diiodo[4.4]dibenzo-24-crown-8 differs dramatically because the latter is absolutely unselective and extracts 28 elements of all studied to the same extent.