Extraction calixarene picolinamide

Distribution Ratios3 and Selectivity for the Extraction of Am and Eu from Aqueous Solutions 10 3 M HN03 into a NPHE/3 10 3 M [Bromocosan] Solution of Picolinamide Calixarenes... 

Picolinamide and thiopicolinamide have been introduced on the lower rims of calixarene scaffolds of various sizes in order to study whether the size of the macrocycle, the cooperation and stereochemical disposition of these binding groups affect the efficiency of extraction and selectivity in the actinide/lanthanide separation. Thus, picolinamide conjugates of calix[4]arene 38-40 and those of calix[6]arene 42-44 and of calix[8]arene 45 and 46 have been formed from appropriate amino derivatives of the corresponding calixarenes and picolinic acid pentafluorophenyl ester. The thiopicolinamide analog 41 has been synthesized from 40 and Lawesson s reagent (2005EJO2338). 

From the various calixarene-based picolinamides studied by Casnati et al. (2005), possibly even the best compound, namely (5,ll,17,23,29,35,41,47-octakis(phenylmethoxy)-49,50,51,52,53,54,55,56-octakis 3-[(pyridine-2-carboxy)amino]propoxy calix[8]arene, = 8, m = 3, R = OBn), see Structure 19.3, exhibited some extraction only at 0.01 M HNO3 at a concentration of 0.0002 M and 0.003 M BrCD in NPHE with a rather low separation factor = 3.3, = 1.3, = 2.54). In addition,... 

Casnati, A., Della Ca , N., Fontanella, M. et al. 2005. Calixarene-based picolinamide extractants for selective An/Ln separation from radioactive waste, Eur. J. Org. Chem. 2338-2348. 

Macerata, E., Casnati, A., D Arpa, O. et al. 2006. Study of the extracting properties of a selected calixarene based picolinamide ligand in different media for the An/Ln separation. In Proceedings of International Youth Nuclear Congress 2006, Stockholm, Sweden, from June 18-23, 2006, Paper No. 268. 

Mariani, M., Macerata, E., Galletta, M. et al. 2007. Partitioning of minor actinides Effects of Gamma irradiation on the extracting capabilities of a selected calixarene-based picolinamide ligand. Rad. Phys. Chem. 76 1285-1289. 

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