Anionic tert-butyl-calix[4]arenes substituted at the narrow and wide rim by cobalt bis(dicarbollide)(1−) ions and CMPO-groups. Effect of stereochemistry and ratios of the functional groups on the platform on the extraction efficiency for Ln(III)/An(III)

Abstract Two ionic calix[4]arenes substituted at the narrow rim with an unpaired number ( n ) of cobalt bis(dicarbollide)(1−) anions ( 1 − ) ( n  = 1 and 3) and (4 −  n ) CMPO groups ( 3c , 4c ) have been synthesized via a three-step procedure based on nitrile substituted calix[4]arene precursors. Conjointly with them, the compound with a paired ratio of the groups, where n  = 2 and the same substituents are located in mutually adjacent 1,2-positions, is reported ( 5c ). Another compound with the paired ratio, but from a wide rim series ( 6c ) ( n  = 2) was successfully prepared starting from calix[4]arenes substituted with two nitro functions and two –OH sites available for further modific…