Reactant-Mediated Diversity in Uranyl Phosphonates

Abstract

Four organically templated uranyl phosphonates, [C4N2H12][UO2F(PO3CH3)]2 (UPNO-1), [C4N2H12][UO2(PO3CH3)(PO2(OH)CH3)]2 (UPNO-2), [C4N2H12][(U2O4F3)(UO2F(H2O))(PO3C6H5)2]·2H2O (UPNO-3), and [C4N2H12]2[(UO2)5(PO3CH2C6H5)6(PO2(OH)CH2C6H5)2] (UPNO-4) have been synthesized under hydrothermal conditions. UPNO-1 contains doubly protonated piperazine templates, [C4N2H12]2+, residing between [UO2F(PO3CH3)]1- anionic layers. Distinct hydrophobic and hydrophilic regions are present between [UO2(PO3CH3)(PO2(OH)CH3)]1- layers in UPNO-2. The template is found in the hydrophilic interlayer space only, completely segregated from the methyl groups of the uranyl methylphosphonate layer, which protrude into the hydrophobic interlayer space. UPNO-3 contains [(U2O4F3)(UO2F(H2O))(PO3C6H5)2]2- layers separated by both piperazine templates, [C4N2H12]2+, and phosphonate phenyl groups, which exist in the same interlayer region. In UPNO-4 the region between [(UO2)5(PO3CH2C6H5)6(PO2(OH)CH2C6H5)2]4- layers is completely hydrophobic as a result of the large number of benzyl groups occupying the interlayer space. The template is found in voids within each layer. The structures of these compounds are dependent upon the reactant concentrations. Crystal data for the compounds are as follows: UPNO-1, a = 6.9288(3) Å, b = 8.1174(4) Å, c = 14.8505(9) Å, β = 91.7173(19)°, monoclinic P21/n (no. 14), Z = 2; for UPNO-2, a = 10.0682(4) Å, b = 8.9121(3) Å, c = 12.9631(7) Å, β = 90.4901(15)°, monoclinic P21/a (no. 14), Z = 2; for UPNO-3, a = 6.7796(1), b = 17.2821(4) Å, c = 24.6754(6) Å, orthorhombic Pbcm (no. 57), Z = 4; and for UPNO-4, a = 11.4732(2) Å, b = 14.9097(2) Å, c = 15.4480(3) Å, α = 64.2307(6)°, β = 70.2105(7)°, γ = 84.136(1)°, triclinic P1̄ (no. 2), Z = 2.

Actinide Polyoxometalates: Incorporation of Uranyl–Peroxo in U‐Shaped 36‐Tungsto‐8‐Phosphate

“…In 2003, OHare et al reported uranyl phosphonate derivatives, [5] and in 2005 Evans et al reported octa-uranium rings with alternating nitride and azide bridges [{(C 5 Me 5 ) 2 U-…”

Synthesis and Characterization of 1‐, 2‐, and 3‐Dimensional Bimetallic UO22+/Zn2+ Phosphonoacetates

“…[1][2][3] In spite of this relevance to separations and nuclear fuel stewardship, our knowledge of the structural chemistry of actinide phosphonates has largely been limited to those uranyl phenylphosphonates reported by Clearfield et al, [4][5][6][7][8][9][10][11][12] as well as a handful of other compounds. [13][14][15][16][17][18] More recently, in an effort to probe the structural chemistry of uranyl phosphonate compounds and extend the known catalog of these materials beyond monophosphonates, the interaction of UO 2 2+ with polyphosphonate [19][20][21][22][23][24] and carboxyphosphonate ligands [25][26][27] has been explored. These ligands are attractive candidates for materials synthesis due to the range of metal-to-ligand binding modes and the potential for novel structural topologies.…”

Structural chemistry of uranium phosphonates

“…Methylphosphonic acid is the simplest organic phosphonate ligand, and it has been used for the syntheses of three uranyl compounds [23,25]. All three uranyl methylphosphonates have layered structures and incorporate uranyl pentagonal bipyramids.…”

“…In the 1990s, Clearfield and coworkers [17][18][19][20][21][22] reported a series of uranium phenylphosphonates with chain or tube structures. After that, the occurrence of uranium phosphonates was sporadic [23,24]. The number of reported uranium phosphonates has skyrocketed due in part to innovative synthetic strategies, which include modulation of the phosphonate ligand, incorporation of transition metals, addition of co-ligands, and introduction of structure-directing agents.…”