Alexander J. Norquist

[NC4H12]2[(UO2)6(H2O)2(SO4)7]: the first organically templated actinide sulfate with a three-dimensional framework structure.

[NC4H12][(UO2)6(H2O)2(SO4)7] is the first organically templated actinide sulfate with a three-dimensional framework structure; it has channels of dimensions 8.5 A x 8.5 A, running along the [001] direction, containing tetramethylammonium cations.

Organically templated uranium(VI) sulfates: understanding phase stability using composition space

Composition space has been used to study the phase stability of organically templated uranium sulfates in the UO2(CH3CO2)2·2H2O–1,3-diaminopropane–H2SO4 system. The syntheses and structures of two new compounds, [N2C3H12][UO2(H2O)(SO4)2] (USO-1) and [N2C3H12][(UO2)2(H2O)(SO4)3] (USO-2), are reported. The relative stability of the crystalline products in this system was found to be dependent upon the reactant mole fraction in the initial reaction gel, based upon the size and location of their respective crystallisation fields in the composition space.

The effects of linear diamine chain length in uranium sulfates

Abstract The synthesis of uranium sulfates under hydrothermal conditions in the presence of a series of structurally related organic templating agents was investigated. 1,2-ethylenediamine, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane and 1,6-diaminohexane were used under identical reaction conditions to elucidate the effects of variation in linear diamine chain length on the extended structures. As the chain length increases the charge density of the doubly protonated amines decreases. Four new compounds were synthesised and structurally characterised. Two types of inorganic frameworks are observed, evolving as a function of amine chain length. The compounds synthesised using 1,2-ethylenediamine and 1,3-diaminopropane contain [UO2(H2O)(SO4)4/2]n2n− chains. The use of 1,4-diaminobutane, 1,5-diaminopentane and 1,6-diaminohexane results in compounds that contain [(UO2)2(SO4)6]8− dimers. The extended structures of these compounds are correlated to the charge density of the organic templating agents.

The first organically templated thorium compounds, [C4N2H12]0.5[ThF5] and [C5N2H14][ThF6]·0.5H2O

Organically templated thorium compounds were synthesized for the first time under hydrothermal conditions; the piperazine containing compound consists of 2-D layers, while the 2-methylpiperazine phase contains unprecedented 1-D chains of face-sharing ThF9 polyhedra.

Structural diversity in organically templated uranium sulfates

The potential of organic amine templates to direct the synthesis of metal sulfate frameworks has been investigated. Eight novel uranyl sulfates have been prepared using a templated uranyl sulfate precursor under hydrothermal conditions. The topologis of the isolated phases vary from the molecular (0-D), to chains (1-D) to layered (2-D) frameworks. [N4C6H22]2[(UO2)2(SO4)6] (USO-10) is molecular or zero-dimensional. Two different types of one-dimensional uranyl-containing chains have been observed. [N2C4H12][UO2(H2O)(SO4)2] (USO-3), [N2C5H14][UO2(H2O)(SO4)2] (USO-4) and [N2C3H12][UO2(H2O)(SO4)2] (USO-9) contain chains based upon a [UO2(SO4)4/2] backbone. [N2C10H10][UO2(SO4)2]·H2O (USO-6) and [N2C6H18][(UO2)2(H2O)3(SO4)3] (USO-7) contain chains based upon a [UO2(SO4)3/3] backbone. Two layered or two-dimensional compounds, [N2C6H14][UO2(H2O)(SO4)2] (USO-5) and [N2C3H5]2[(UO2)2(SO4)3] (USO-8) have also been isolated. All the new phases have been characterised using a range of physical techniques including single crystal X-ray structure analysis.