Cobalt bis(dicarbollide) ions functionalized by CMPO-like groups attached to boron by short bonds; efficient extraction agents for separation of trivalent f-block elements from highly acidic nuclear waste.
Abstract
New boron substituted cobalta bis(dicarbollide)(1-) ion (1) derivatives of formula [(8,80-(RPhP(O)(CH2)n-C(O) N)<(1,2-C2B9H10)(2)-3,3'-Co] (R = Ph or C8H17, n = 1, 3a, 3b; R = Ph, n = 2, 3c), [(8-(Ph2P(O)CH2-C(O)NR)(1,2-C2B9H10))(1',2'-C2B9H11)-3,3'-Co] (R-1 = H, C2H5, CH2C6H5, 5a-c) and [(8-((RPhP)-R-2(O)CH2C(O)-N( R-1)CH2-1,2-C2B9H10))(8'-CH3O-1',2'-C2B9H10)-3,3'-Co] (R-1 = Benzyl, R-2 = Ph or C8H17, 7a,b) were prepared with the aim to develop a new class of efficient extraction agents for partitioning of polyvalent f-block elements, i.e. lanthanides and actinides from high-level activity nuclear waste. The anionic ligands were characterized by multinuclear NMR spectroscopy and MS, the structures of Cs3a and the calcium complex of 7a were determined by X-ray diffraction analysis.
The crystallographic study of the Cs3a proved a formation of linear chains in the structure, where the metal cation is coordinated by oxygen atoms of the CMPO terminal groups.