Synthesis, Structure, and Characterization of Uranium(IV) Phenyl Phosphonate, U(O3PC6H5)2, and Uranium(IV) Pyro Phosphate, UP2O7

Triclinic–Cubic Phase Transition and Negative Expansion in the Actinide IV (Th, U, Np, Pu) Diphosphates

“…51 They are also comparable to the 137°angle of Cabeza's room-temperature cubic model featuring split positions for O b . 30 The bending of the P−O−P linkages results in a strong distortion of the PO 4 tetrahedra. Typically, as shown in Figure 3 for the P 2 O 7 unit near (1/2,1/2,1/2), the O b −P−O angles involving a nonbridging O on the same side as the opposite phosphorus are higher than the other ones.…”

Thermal Behavior of Zinc Phenylphosphonate and Structure Determination ofγ-Zn2P2O7from X-Ray Powder Diffraction Data

“…Some elements of the thermal decomposition of zinc phenylphosphonate monohydrate were reported by Frink et al (6), showing the formation of the anhydrous phase, but the next stages of the decomposition were not completely elucidated. On the other hand, in a recent work on uranium phenylphosphonate it has been shown that uranyl diphosphate is formed from thermal decomposition (12). Also, zinc diphosphates have been observed among the decomposition products of related zinc di(tert-butyl)phosphate complexes (13).…”

Structural chemistry of uranium phosphonates

“…Another 3D structure also contains seven-coordinate uranium centers, described as square antiprisms with missing vertices that are linked by methylenediphosphonate ligands [32]. The only tetravalent uranium monophosphonate is [45] U(PhP) 2 [76]. The lamellar structure of U(PhP) 2 consists of UO 6 octahedra bridged by phenylphosphonate ligands in the ab plane (Fig.…”

“…However, six-coordinate and seven-coordinate uranium polyhedra also occur in uranium(IV) phosphonates. Four kinds of phosphonate ligands, including one alkylphosphonic acid (MDP) and three arylphosphonic acids (PhP, bbp and o-bbp), have been successfully used for the syntheses of uranium(IV) phosphonates, which range from clusters to framework structures [32,45,49,76,77]. Hexanuclear clusters U 6 (H 2 O) m (o-bbpH) 6 (NO 3 ) n 6−n [77] are formed by six UO 9 polyhedra bridged by six monoprotonated 1,2-phenylenediphosphonate ligands (Fig.…”

“…(a) Cluster structure of U6(H2O)m(o-bbpH)6(NO3)n 6−n[77], (b) chain of U(o-bbpH2)2·1.5H2O[49], (c) sheet of U(PhP)2[76], and (d) framework of U2(Hbbp)2(H2bbp)[45].…”