C-substituted bis(dicarbollide) metal compounds as sensors and extractantsof radionuclides from nuclear wastes

[3,3'-M(1,2-C2B9H11)(2)](-) (M = Co3+, Fe3+, Ni3+) compounds have been impl emented in PVC membranes to study their performance as Cs+ sensors in ion s elective electrodes. They show a near-Nernstian response close to 51 mV (de cade)(-1). The three display a similar behaviour, and the [3,3'-Co(1,2-C2B9 H11)(2)](-) anion was chosen as the parent chemical on which C-substitution , both alkyl or aromatic, were done. The species [3,3'-Co(1-CH3-2-(CH2)(n)O R-1,2-C2B9H9)(2)](-) ([4](-): n = 3, R = -CH2CH3; [5](-): n = 3, R = -(CH2) (2)OCH3; [6](-): n = 3, R = -(CH2)(3)CH3; [7](-): n = 6, R = -(CH2)(3)CH3), and [3,3'-Co(1-C6H5-1,2-C2B9H10)(2)](-) ([8](-)) and [3,3'-Co(1,7-(C6H5)(2 )-1,7-C2B9H9)(2)](-) ([9](-)) were tested for Cs-137, Sr-90 and Eu-152 in e xtraction. Permeability tests on supported liquid membranes with H[6], H[7] and H[9] have shown that these compounds present the highest values report ed so far for this sort of radionuclide transport experiments. The structur e of the carrier CN((CPI,),CH,),1[9] is reported. Crystals were monoclinic, space group P2(1)/c (no.14), a = 18.255(4) Angstrom, b = 15.871(9) Angstro m, c = 18.684(14) Angstrom, beta = 105.64(3)degrees, V = 5213(5) Angstrom(3 ) and Z = 4. The carbons apart structure may be one of the reasons of the e xcellent performance of this compound in Cs+ transport in SLM with nitrophe nylhexyl ether as a solvent. (C) 1999 Elsevier Science S.A. All rights rese rved.