Jason R. Price

MX1: a bending‐magnet crystallography beamline serving both chemical and macromolecular crystallography communities at the Australian Synchrotron

The macromolecular crystallography beamline MX1 at the Australian Synchrotron is described.

Hysteretic Four‐Step Spin Crossover within a Three‐Dimensional Porous Hofmann‐like Material

Materials that display multiple stepped spin crossover (SCO) transitions with accompanying hysteresis present the opportunity for ternary, quaternary, and quinary electronic switching and data storage but are rare in existence. Herein, we present the first report of a four-step hysteretic SCO framework. Single-crystal structure analysis of a porous 3D Hofmann-like material showed long-range ordering of spin states: HS, HS0.67 LS0.33 , HS0.5 LS0.5 , HS0.33 LS0.67 , and LS. These detailed structural studies provide insight into how multistep SCO materials can be rationally designed through control of host-host and host-guest interactions.

Uranium(VI) complexes with isonicotinic acid: from monomer to 2D polymer with unique U–N bonding

Two new uranium(VI) complexes with isonicotinic acid (HINT) have been synthesized and characterized. [(UO2)(NO3)2(HINT)2] (1) has a monomeric structure constructed of a hexagonal bipyramidal uranyl centre, two nitrate anions and two monodentate HINT in trans-positions. [(UO2)(OH)(INT)] (2) has a two-dimensional (2D) polymeric structure constructed of uranyl hydroxyl 1D pillars and μ3-bridging INT anions; the first observation of INT in μ3-bridging mode for U(VI) ion via U–N bonding. Thermal analysis confirmed both complexes lost coordinated INT ligands followed by further decomposition to form U3O8. Raman spectroscopy has confirmed the presence of uranyl ion and INT ligand in both complexes as well as the existence of nitrate vibrations in 1 and hydroxyl vibrations in 2. Their photoluminescence properties have been investigated.

Kinetics vs. thermodynamics: a unique crystal transformation from a uranyl peroxo-nanocluster to a nanoclustered uranyl polyborate

A novel method to prepare a nano-clustered uranyl polyborate in aqueous solution at room temperature has been developed. The initially formed kinetically favoured sodium uranyl peroxide yellow crystals transform, in the presence of boric acid, to the thermodynamically stable sodium uranyl polyborate in light yellow-green single crystal form.

The crystal structure of camerolaite and structural variation in the cyanotrichite family of merotypes

Abstract We present Raman data for camerolaite, cyanotrichite and carbonatecyanotrichite, and using synchrotron single-crystal X-ray diffraction have solved the structure of camerolaite from the Tistoulet Mine, Padern, Aude Department, France. Camerolaite crystallizes in space group P1 with the unit-cell parameters: a = 6.3310(13) Å , b = 2.9130(6) Å , c = 10.727(2) Å , α = 93.77(3)°, β = 96.34(3)°, γ =79.03(3)°, V = 192.82(7) Å3 and Z = ⅔ , with respect to the ideal formula from the refinement, Cu6Al3(OH)18(H2O)2[Sb(OH)6](SO4). The crystal structure was solved to R1 = 0.0890 for all 1875 observed reflections [Fo > 4σFo] and 0.0946 for all 2019 unique reflections. The P cell has been transformed into a C-centred cell that aids comparison with that of the structurally related khaidarkanite by aC = 2aP - bP, giving parameters a = 12.441(3), b = 2.9130(6), c = 10.727(2) Å , α = 93.77(3), β = 95.57(3), γ = 92.32(3)° and Z = ⅔ in C1. Edge-sharing octahedral ribbons Cu2Al(O,OH,H2O)8 form hydrogen-bonded layers ǁ (001), as in khaidarkanite. The partially occupied interlayer Sb and S sites of the average structure are in octahedral and tetrahedral coordination by oxygen, respectively. They cannot be occupied simultaneously, which leads to regular alternation of [Sb(OH)6]- and SO42- groups in rods ǁ y, resulting in local tripling of the periodicity along y for the Sb(OH)6-SO4 rods. Thus, camerolaite has a ‘host-guest’ structure in which an invariant host module (layers of Cu-Al ribbons) has embedded rod-like guest modules with a longer periodicity. Coupling between the phases of these rods is only short-range, resulting in diffuse X-ray scattering rather than sharp superstructure reflections. Similar disorder is known for parnauite, and is deduced for other members of the cyanotrichite group (cyanotrichite, carbonatecyanotrichite and khaidarkanite). Group members all share the Cu-Al ribbon module but have interlayer rods of different compositions and topologies; thus, they form a merotypic family. The low symmetry of the camerolaite average structure suggests other possibilities for structure variation in the group, which are discussed.

Chiral edge-shared octahedral chains in liskeardite, [(Al,Fe)32(AsO4)18(OH)42(H2O)22]·52H2O, an open framework mineral with a pharmacoalumite-related structure

Abstract The type specimen of liskeardite, (Al,Fe)3AsO4(OH)6·5H2O, from the Marke Valley Mine, Liskeard District, Cornwall, has been reinvestigated. The revised composition from electron microprobe analyses and structure refinement is [Al29.2Fe2.8(AsO4)18(OH)42(H2O)22]·52H2O. The crystal structure was determined using synchrotron data collected on a 2 μm diameter fibre at 100 K. Liskeardite has monoclinic symmetry, space group I2, with the unit-cell parameters a = 24.576(5), b = 7.754(2) Å, c = 24.641(5) Å, and β = 90.19(1)°. The structure was refined to R = 0.059 for 9769 reflections with I > 3σ(I). It is of an open framework type in which intersecting polyhedral slabs parallel to (101) and (101̅) form 17.4 Å × 17.4 Å channels along [010], with water molecules occupying the channels. Small amounts (<1 wt.%) of Na, K and Cu are probably adsorbed at the channel walls The framework comprises columns of pharmacoalumite-type, intergrown with chiral chains of six cis edge-shared octahedra. It can be described in terms of cubic close packing, with vacancies at both the anion and cation sites. The compositional and structural relationships between liskeardite and pharmacoalumite are discussed and a possible mechanism for liskeardite formation is presented

3d transition metal complexes with a julolidine–quinoline based ligand: structures, spectroscopy and optical properties

A Schiff base type ligand with the combination of the julolidine and the quinoline groups has been reported as a potential chemosensor in detecting the cobalt(II) ion among other heavy and transition metal ions in solution. However, no crystal structure of such a ligand with any metal ions has been reported. In this work, its complexation with 3d transition metal ions (Mn(II), Co(II), Ni(II), Cu(II) and Zn(II)) has been investigated with five new complexes being synthesised, and spectroscopically and structurally characterised. [Mn2L2(CH3OH)2(CH3COO)2]·CH3OH (1) {HL (C22H21N3O) = ((E)-9-((quinolin-8-ylimino)methyl)-1,2,3,5,6,7-hexahydropyrido[3,2,1-ij]quinolin-8-ol)} shows a dinuclear structure with two Mnu2006:u2006Lu2006:u2006acetate (1u2006:u20061u2006:u20061) units bridged by two methanol molecules. [CoL2(NO3)]·CH3OH·H2O (2) and [NiL2]·H2O (3) exhibit mononuclear structures with a Cou2006:u2006L or Niu2006:u2006L ratio of 1u2006:u20062. [CuL(CH3COO)]·1/3CH3OH (4) demonstrates a mononuclear structure and the Cu ion has a square planar coordination polyhedron with a L ligand and a highly non-symmetrical acetate anion. [Zn2L2(CH3COO)2]·CH3OH (5) has two types of dinuclear units, both with two ZnL units bridged by two acetate anions but in three different bridging coordination modes. Their vibrational modes, absorption and photoluminescence properties have also been investigated.

Thorium(IV) organic frameworks with aromatic polycarboxylate ligands

Contrary to the fairly well established structural chemistry of uranium(VI) with aromatic polycarboxylate ligands, the knowledge on thorium(Th) structural chemistry with this family of ligands is very limited. In this paper, we report the synthesis, spectroscopic and thermal studies, and crystal structures of three Th organic frameworks with 1,2,4,5-benzenetetracarboxylate (btca) or 1,4-benzenedicarboxylate (bdc). Both [Th(btca)(DMF)2(H2O)] (1) and [Th(bdc)2(DMF)2] (2) (DMFxa0=xa0dimethylformamide) have two dimensional (2D) layered structures constructed with 9- (1) or 10- (2) fold coordinated Th polyhedrons and µ4-btca (1) or µ2-bdc (2) ligands, respectively, with two coordinated DMF molecules in cis- (1) or trans- (2) positions on each Th atom. The third phase, [Th(bdc)2] (3), has a 3D pillared framework built with eightfold coordinated Th polyhedrons and µ4-bdc ligands. Their vibrational modes have been investigated and correlated to the structures. VT-PXRD confirmed that 3 is thermally robust to 500xa0°C and the weight loss at ~300xa0°C is due to the loss of water molecules in the solvent accessible voids in the crystal lattice.Graphical AbstractThorium(IV) organic frameworks (TOC): Three new thorium organic frameworks with aromatic polycarboxylate ligands have been synthesized and characterized. 2D layered structures are favored at room temperature and a thermal robust, 3D thorium organic framework has been made under hydrothermal conditions. Their vibrational modes and thermal stabilities have been further investigated.

The influence of stereochemically active lone-pair electrons on crystal symmetry and twist angles in lead apatite-2H type structures

Abstract Lead-containing (Pb-B-X)-2H apatites encompass a number of [AF]4[AT]6(BO4)6]X2 compounds used for waste stabilization, environmental catalysis and ion conduction, but the influence of the stereochemically active lone-pair electrons of Pb2+ on crystal chemistry and functionality is poorly understood. This article presents a compilation of existing structural data for Pb apatites that demonstrate paired electrons of Pb2+ at both the AF and AT results in substantial adjustments to the PbFO6 metaprism twist angle, φ. New structure refinements are presented for several natural varieties as a function of temperature by single-crystal X-ray diffraction (XRD) of vanadinite-2H (ideally Pb10(VO4)6Cl2), pyromorphite-2H (Pb10PO4)6Cl2), mimetite-2H/M (Pb10(As5+O4)6Cl2) and finnema-nite-2H (Pb10(As3+O3)6Cl2). A supercell for mimetite is confirmed using synchrotron single-crystal XRD. It is suggested the superstructure is necessary to accommodate displacement of the stereochemically active 6s2 lone-pair electrons on the Pb2+ that occupy a volume similar to an O2- anion. We propose that depending on the temperature and concentration of minor substitutional ions, the mimetite superstructure is a structural adaptation common to all Pb-containing apatites and by extension apatite electrolytes, where oxide ion interstitials arc found at similar positions to the lone-pair electrons. It is also shown that plumbous apatite framework flexes substantially through adjustments of the PbFO6 metaprism twist-angles (φ) as the temperature changes. Finally, crystal-chemical [100] zoning observed at submicron scales will probably impact on the treatment of diffraction data and may account for certain inconsistencies in reported structures.

Dioxo-vanadium(V), oxo-rhenium(V) and dioxo-uranium(VI) complexes with a tridentate Schiff base ligand

The complexation of a julolidine–quinoline based tridentate ligand with three oxo-metal ions, dioxo-vanadium(V), oxo-rhenium(V) and dioxo-uranium(VI), has been investigated with four new complexes being synthesised and structurally characterised. (VO2L)·2/3H2O (1) {HL (C22H21N3O) = ((E)-9-((quinolin-8-ylimino)methyl)-1,2,3,5,6,7-hexahydropyrido[3,2,1-ij]quinolin-8-ol)} has a VO2L neutral mononuclear structure with a five-fold coordinated vanadium metal centre in a distorted trigonal bipyramidal geometry. (ReOL2)2(ReCl6)·7DMF (2) [DMF = dimethylformamide] exhibits a mixed valent rhenium complex with a (ReOL2)+ cationic unit in a distorted octahedral metal coordination geometry, charge balanced with (ReCl6)2− anions. [(UO2)L(H2O)2]2·2(NO3)·HL·4H2O (3) and [(UO2)L(CH3OH)2](NO3)·CH3OH (4) both have (UO2L)+ cationic mononuclear structures with either coordinated water or methanol molecules in pentagonal bipyramidal coordination geometries for the uranium metal centres. Intra-/intermolecular interactions including hydrogen bonding and π–π interactions are common and have been discussed. In addition, optical absorption and photoluminescence properties have been investigated.