Differential Ion Exchange in Elliptical Uranyl Diphosphonate Nanotubules

Abstract

Nanotubular bells: A simple route to a uranyl diphosphonate with an elliptical nanotubular structure has been developed (see picture; C black, O red, Cs blue, F yellow, UO7 green pentagonal bipyramids, phosphonate violet tetrahedra). The interior of the nanotubules provides a different chemical environment than the exterior with regards to the exchange of Cs+ cations for Ag+ cations, thus demonstrating that uranyl nanotubules are functional materials.

Structural and spectroscopic characterization of two new layered uranyl(VI) p-xylenediphosphonate compounds synthesized via ionothermal method

“…The crystal chemistry of actinide phosphonates is an important subfield of metal phosphonates, where major attention was paid to uranium [13][14][15][16][17][18][19] and thorium [20][21][22], with only a few neptunium [22][23][24], plutonium [25][26][27][28], and americium [28] complexes. Layered structure is always observed in uranyl phosphonates, due to the nature of equatorial coordination sites (from four to six) of the uranyl ion, leading the structure to 2D topologies [19,[29][30][31][32][33][34].…”

Barium uranyl diphosphonates

“…Because of their relevance to nuclear fuel stewardship and use in reprocessing used nuclear fuel, the knowledge of the structural chemistry of actinide phosphonates has evolved from early work on uranyl phenylphosphonates reported by Clearfield et al [31][32][33][34][35][36] to more complicated structures. To date, pillared, nanotubular and templated uranyl diphosphonates have been synthesized [37][38][39]. Also, the actinide metal site has been probed by using Th(IV), U(IV) and U(VI), Np(IV) and Np(VI), and Pu(IV) diphosphonates, allowing structural comparisons to be made [40].…”

Structural chemistry of uranium phosphonates

“…16b). The uranyl chain is slightly different than Chain II in CsUbbp-1 [42] which contains PO 3 groups that chelate and bridge the dimers. In CsUbpbp-1, one of the PO 3 moieties does not participate in connecting the chains or the dimers.…”

“…1,4-Phenylenediphosphonic acid is the most intensively investigated of the three, and twenty-seven uranyl phosphonate compounds including two 1D, eight 2D, and thirteen 3D structures have been prepared [39,[41][42][43][44][45][46][47][48]. Pillared structures often occur by using the rigid phenyl ring as spacers to separate the uranyl phosphonate partial structures.…”

“…The tubular structures and their uranyl phosphonate chain components (and their graphical representations) in CsUbbp-1 (a)[42] and CsUbpbp-1 (b)[43].…”