Two unique series of lanthanide complexes [Ln(Ph3PO)4(NCS)3] (Ln = La-Tb, except Pm) and [Ln(Ph3PO)3(NCS)3] (Ln = Sm-Lu, Y) have been structurally characterised. The isomorphous series [Ln(Ph3PO)4(NCS)3] crystallises in the monoclinic centrosymmetric space group P21/c, and the metals display a capped octahedral coordination geometry. In contrast, the isomorphous series [Ln(Ph3PO)3(NCS)3] (Ln = Sm-Lu, Y) crystallise in the non-centrosymmetric space group R3, with the metal displaying an octahedral coordination geometry; the fac-isomer being observed in all cases. Intriguingly, for the metals Sm-Tb both the seven and six coordinate complexes can be isolated from the respective synthetic routes suggesting a structural equilibrium in solution. An analysis of the distortions of the ligand polyhedron in the two series using the continuous shape measurement (CShMs) method suggests trends across the series relating to the fit of the ligands with the size of the lanthanide ions.

The current discussion on whether scandium, yttrium and lanthanum should represent Group 3 in the Periodic Table or whether lutetium should replace lanthanum in the group has prompted us to further explore the structural chemistry of the Group 3 elements and compare the coordination numbers and coordination geometries adopted. The steric and electronic properties of the coordinated ligands have a major influence on the structures adopted. We report the synthesis and crystal structure determination of an unusual dinuclear scandium complex [(bipy)(NO3)2Sc(µ-OH)2Sc(NO3)2(bipy)] obtained by the reaction of hydrated scandium nitrate with 2,2′-bipyridyl (bipy) in either ethanol or nitromethane. The crystal structure of the complex shows that the scandium centers are eight coordinate, and the structure obtained contrasts with related complexes found in the lanthanide series [Ln(bipy)2(NO3)3] and [Ln(phen)2(NO3)3] (phen = phenanthroline) and in [M(terpy)(NO3)3] (M = Sc, Er–Lu), where these complexes are all mononuclear.

Fe supported catalysts show great promise for enabling practical environmental catalysis, exemplified by the catalytic wet peroxide oxidation (CWPO) process. In order to mitigate the Fe leaching issue, a strategy of assembling zeolitic coatings with intraframework Fe (ferrisilicate) on SiC foams was developed, showing a good stability in CWPO and a low Fe leaching of 2.0 mg l(-1). Direct hydrothermal synthesis of ferrisilicate/SiC foam composites was systematically studied, showing that their characteristics depend on the growth time, pH value and iron concentration of the growth solution. Selected ferrisilicate/SiC foam composite was evaluated using the continuous CWPO of phenolic aqueous solution at 60 degrees C. The open-cell size of SiC foam was varied between 800 and 2,000 mu m and showed insignificant effect on the hydrodynamics of the flow process at 1 ml min(-1), but the process efficiency in terms of phenol and total-organic-carbon (TOC) conversions was favored by a high surface-to-volume ratio (i.e. small open-cell sizes). Ferrisilicate/SiC foam catalysts (average open-cell size = 800 mu m) showed good stability in the model system with the stable conversions of phenol (97%), H2O2 (84%) and TOC (37%) over 24 h time-on-stream.

Crystallographic studies of monosulfonated azo dyes have concentrated on the salt forms that contain the azo anion. Here we present a study that compares the structures of these anions with protonated free acid forms and with doubly deprotonated dianion forms. To this end, the new single crystal diffraction structures of 13 systematically related free acid forms of monosulfonated azo dyes are presented, together with three new structures of doubly deprotonated forms and two new structures of Na salt forms of azo anions. No structures of dideprotonated monosulfonated azo dyes have previously been reported and this paper also reports the first crystal structure of an azo dye with a hydronium cation. The geometries of the free acid, anion and dianion forms are compared to literature equivalents. It is shown that protonation of the azo bond gives predictable bond lengthening and shortening, which is of a greater magnitude than similar effects caused by azo-hydrazone tautomerisation, or the smaller again effects caused by the resonance electron donation from O or N based substituents. The dianion containing structures have twisted dianion geometries that can be understood based on the resonance effects of the phenoxide groups and upon the needs to bond to a relatively high number of metal cations.

By combining laboratory-based x-ray diffraction stress analysis with optical digital image correlation recorded in-situ during tensile loading, a new methodology has been developed to obtain for surface specific stress-strain curves. This novel methodology has been validated by comparing the reconstructed stress-strain curves from the x-ray diffraction/optical digital image correlation approach with stress-strain curves recorded using standard methods. The validated methodology enables now the recording of standard mechanical test data of altered surface layers, such as shot peened and machined surfaces or from proton-irradiated samples where the irradiated layer is limited to a depth of 10 s of microns.

The amino acidl-threonine undergoes three phase transitions between ambient pressure and 22.3 GPa which modify both hydrogen bonding and the molecular conformation.

Background:Current prognostic scoring systems in multiple myeloma lack consensus and are often clinically impractical. The key diagnostic features known as CRAB; hypercalcaemia (C), renal impairment (R), anaemia (A), and bone lesions (B), are known to represent end organ damage in myeloma.Aims:We aimed to produce a simplified and practical prognostic tool for use in multiple myeloma patients as an alternative to current practice, therefore enabling prognostic guidance to be distributed to a wider group of patients. Since the laboratory tests required to calculate CRAB score are routinely undertaken in clinical practice, we proposed a method of predicting outcome based on these results alone, which has not yet been reported.Methods:We examined a combined database of clinical and survival information for 314 patients from Brighton and Worthing, Sussex, UK, over a 6 year period, who were newly diagnosed with myeloma, and represent real‐world clinical experience. To determine the presence of a CRAB feature, the cut‐off values previously defined by the International Myeloma Working Group (IMWG) were used; serum calcium >2·75 mmol/L, serum creatinine >177 μmol/L, haemoglobin <100 g/L (or >20 g/L below lower limit of normal), and one or more osteolytic lesion on skeletal radiography, CT, PET‐CT or MRI.Patients were stratified into five CRAB score groups by having either 0, 1, 2, 3 or 4 CRAB features at initial presentation, with a score of 0 denoting a diagnosis of smouldering myeloma. We then studied the relationship between CRAB score and overall survival using Kaplan Meier curves plotted by the statistics programme SPSS.Results:Our analysis reveals that each additional CRAB feature confers a stepwise statistically significant poorer outcome in terms of overall survival as shown in Figure 1a. This result was regardless of the treatment regimen the patient received and gave 5‐year survival percentages of 81%, 58%, 41%, 22% and 0% for patients with CRAB scores 0–4 respectively. We also found CRAB score to have coherence with the current International Staging System (ISS) scoring system, which combines serum albumin as a measure of general patient health with β2‐microglobulin as a measure of tumour bulk to estimate risk.Cytogenetic data required for the revised ISS score was not undertaken for the majority of patients, highlighting the lack of feasibility of this system in practice, although we did observe higher CRAB scores for those patients identified with poor risk chromosomal abnormalities. A trend for higher ISS score with higher CRAB score was observed, further validating the CRAB scoring system (figure 1b).Summary/Conclusion:Our study shows that the CRAB score yields accurate prognostic predictions for patients with newly diagnosed multiple myeloma based on simple clinical criteria. It has more prognostic categories than the currently used ISS score (5 versus 3) and superior clinical utility than expensive and time‐consuming cytogenetic‐based scoring systems that have been recently described. These results indicate that the CRAB score may provide a useful and reliable tool to guide prognostic evaluation in newly diagnosed myeloma patients, requiring only routine laboratory testing to be undertaken, and therefore greater availability to patients in diverse clinical settings.image

Reaction of iron(IIII)chloride with the free base tetrakis(4-carboxyphenyl)porphyrin (H2TCPP) in the presence of different bases leads to the formation of a series of iron/porphyrin metal-organic frameworks. Such a crystal engineering approach led to the obtaining of four structures presenting three different topologies and inorganic secondary building units. Depending on the synthesis conditions, isolated Fe-III octahedra, diiron(II) paddle wheel dimers, or extended [Fe-III(OH)O-4](n) chains could be obtained in a controlled manner. The influence of the synthetic conditions on the final structure and the oxidation state of iron is discussed. Stability of the porous solids towards air and water is studied, and their intrinsic porosity is assessed.

Despite an absence of conventional porosity, the 1D coordination polymer [Ag-4(O2C(CF2)(2)CF3)(4)(TMP)(3)] (1; TMP=tetramethylpyrazine) can absorb small alcohols from the vapour phase, which insert into AgO bonds to yield coordination polymers [Ag-4(O2C(CF2)(2)CF3)(4)(TMP)(3)(ROH)(2)] (1-ROH; R=Me, Et, iPr). The reactions are reversible single-crystal-to-single-crystal transformations. Vapour-solid equilibria have been examined by gas-phase IR spectroscopy (K=5.68(9)x10(-5) (MeOH), 9.5(3)x10(-6) (EtOH), 6.14(5)x10(-5) (iPrOH) at 295K, 1bar). Thermal analyses (TGA, DSC) have enabled quantitative comparison of two-step reactions 1-ROH12, in which 2 is the 2D coordination polymer [Ag-4(O2C(CF2)(2)CF3)(4)(TMP)(2)] formed by loss of TMP ligands exclusively from singly-bridging sites. Four polymorphic forms of 1 (1-A(LT), 1-A(HT), 1-B-LT and 1-B-HT; HT=high temperature, LT=low temperature) have been identified crystallographically. In situ powder X-ray diffraction (PXRD) studies of the 1-ROH12 transformations indicate the role of the HT polymorphs in these reactions. The structural relationship between polymorphs, involving changes in conformation of perfluoroalkyl chains and a change in orientation of entire polymers (A versus B forms), suggests a mechanism for the observed reactions and a pathway for guest transport within the fluorous layers. Consistent with this pathway, optical microscopy and AFM studies on single crystals of 1-MeOH/1-A(HT) show that cracks parallel to the layers of interdigitated perfluoroalkyl chains develop during the MeOH release/uptake process.

The resonant scattering and diffraction beamline P09 at PETRA III at DESY is equipped with a 14 T vertical field split-pair magnet. A helium-3 refrigerator is available that can be fitted inside the magnet's variable-temperature insert. Here the results of a series of experiments aimed at determining the beam conditions permitting operations with the He-3 insert are presented. By measuring the tetragonal-to-orthorhombic phase transition occurring at 2.1 K in the Jahn-Teller compound TmVO4, it is found that the photon flux at P09 must be attenuated down to 1.5 × 10(9) photons s(-1) for the sample to remain at temperatures below 800 mK. Despite such a reduction of the incident flux and the subsequent use of a Cu(111) analyzer, the resonant X-ray magnetic scattering signal at the Tm LIII absorption edge associated with the spin-density wave in TmNi2B2C below 1.5 K is intense enough to permit a complete study in magnetic field and at sub-Kelvin temperatures to be carried out.

We report two isoreticular 3D peptide-based porous frameworks formed by coordination of the tripeptides Gly-L-His-Gly and Gly-L-His-L-Lys to Cu-II which display sponge-like behaviour. These porous materials undergo structural collapse upon evacuation that can be reversed by exposure to water vapour, which permits recovery of the original open channel structure. This is further confirmed by sorption studies that reveal that both solids exhibit selective sorption of H2O while CO2 adsorption does not result in recovery of the original structures. We also show how the pendant aliphatic amine chains, present in the framework from the introduction of the lysine amino acid in the peptidic backbone, can be post-synthetically modified to produce urea-functionalised networks by following methodologies typically used for metal-organic frameworks built from more rigid classical linkers.

The hydrostatic compression of the chiral metal-organic framework [Ni(L-Asp)(H2O)(2)] center dot H2O (NiAsp-I) has been studied to 6.07 GPa by single crystal X-ray diffraction. Over the course of this pressure range the compound undergoes a phase transition between 0.58 GPa and 1.26 GPa, yielding NiAsp-II. Both polymorphs are orthorhombic, P2(1)2(1)2(1), and feature 1D chains of Asp-Ni-Asp moieties. During the transition, the Ni(II) octahedra rotate, resulting in a dramatic shift in the position of the axial bonds with respect to the direction of polymer formation, and gives rise to an anisotropic compression of the unit cell dimensions.

Abstract The structure of a high-pressure polymorph of propionamide is reported from synchrotron single-crystal X-ray diffraction data. The polymorph was obtained by in situ high-pressure crystallisation from solution in a diamond-anvil cell at 0.9 GPa; its structure is 23% denser than that of the ambient-pressure polymorph at STP. PIXEL lattice and dimer energies calculations indicate that the ambient- and high-pressure polymorphs are energetically competitive. Together with acetamide and formamide, this is the third high-pressure polymorph of an aliphatic amide crystallising as a Z′=2 structure; the H-bonded network is however significantly different from the ones reported for the other two compounds. This study highlights the power of in situ high-pressure crystallisation techniques for accessing novel polymorphic forms of molecular compounds.

AbstractThe synthesis of metal–organic frameworks with large three‐dimensional channels that are permanently porous and chemically stable offers new opportunities in areas such as catalysis and separation. Two linkers (L1=4,4′,4′′,4′′′‐([1,1′‐biphenyl]‐3,3′,5,5′‐tetrayltetrakis(ethyne‐2,1‐diyl)) tetrabenzoic acid, L2=4,4′,4′′,4′′′‐(pyrene‐1,3,6,8‐tetrayltetrakis(ethyne‐2,1‐diyl))tetrabenzoic acid) were used that have equivalent connectivity and dimensions but quite distinct torsional flexibility. With these, a solid solution material, [Zr6O4(OH)4(L1)2.6(L2)0.4]⋅(solvent)x, was formed that has three‐dimensional crystalline permanent porosity with a surface area of over 4000 m2 g−1 that persists after immersion in water. These properties are not accessible for the isostructural phases made from the separate single linkers.

The solid-state, low-temperature linkage isomerism in a series of five square planar group 10 phosphino nitro complexes have been investigated by a combination of photocrystallographic experiments, Raman spectroscopy and computer modelling. The factors influencing the reversible solid-state interconversion between the nitro and nitrito structural isomers have also been investigated, providing insight into the dynamics of this process. The cis-[Ni(dcpe)(NO2)2] (1) and cis-[Ni(dppe)(NO2)2] (2) complexes show reversible 100 % interconversion between the h-NO2 nitro isomer and the h-ONO nitrito form when single-crystals are irradiated with 400 nm light at 100 K. Variable temperature photocrystallographic studies for these complexes established that the metastable nitrito isomer reverted to the ground-state nitro isomer at temperatures above 180 K. By comparison, the related trans complex [Ni(PCy3)2(NO2)2] (3) showed 82 % conversion under the same experimental conditions at 100 K. The level of conversion to the metastable nitrito isomers is further reduced when the nickel centre is replaced by palladium or platinum. Prolonged irradiation of the trans-[Pd(PCy3)2(NO2)2] (4) and trans-[Pt(PCy3)2(NO2)2] (5) with 400 nm light gives reversible conversions of 44 and 27 %, respectively, consistent with the slower kinetics associated with the heavier members of group 10. The mechanism of the interconversion has been investigated by theoretical calculations based on the model complex [Ni(dmpe)Cl(NO2)] .

, 1624 (2010); 327 Science et al. Chang Hwan Kim in Simulated Diesel Exhaust x NO Strontium-Doped Perovskites Rival Platinum Catalysts for Treating This copy is for your personal, non-commercial use only. clicking here. colleagues, clients, or customers by , you can order high-quality copies for your If you wish to distribute this article to others here. following the guidelines can be obtained by Permission to republish or repurpose articles or portions of articles ): May 28, 2014 www.sciencemag.org (this information is current as of The following resources related to this article are available online at http://www.sciencemag.org/content/327/5973/1624.full.html version of this article at: including high-resolution figures, can be found in the online Updated information and services, http://www.sciencemag.org/content/suppl/2010/03/24/327.5973.1624.DC1.html can be found at: Supporting Online Material http://www.sciencemag.org/content/327/5973/1624.full.html#related found at: can be related to this article A list of selected additional articles on the Science Web sites http://www.sciencemag.org/content/327/5973/1624.full.html#ref-list-1 , 4 of which can be accessed free: cites 27 articles This article 2 article(s) on the ISI Web of Science cited by This article has been http://www.sciencemag.org/content/327/5973/1624.full.html#related-urls 4 articles hosted by HighWire Press; see: cited by This article has been http://www.sciencemag.org/cgi/collection/chemistry Chemistry subject collections: This article appears in the following

A flexible metal-organic framework selectively sorbs para- (pX) over meta-xylene (mX) by synergic restructuring around pX coupled with generation of unused void space upon mX loading. The nature of the structural change suggests more generally that flexible structures which are initially mismatched in terms of fit and capacity to the preferred guest are strong candidates for effective molecular separations.

Porous materials are attractive for separation and catalysis-these applications rely on selective interactions between host materials and guests. In metal-organic frameworks (MOFs), these interactions can be controlled through a flexible structural response to the presence of guests. Here we report a MOF that consists of glycyl-serine dipeptides coordinated to metal centres, and has a structure that evolves from a solvated porous state to a desolvated non-porous state as a result of ordered cooperative, displacive and conformational changes of the peptide. This behaviour is driven by hydrogen bonding that involves the side-chain hydroxyl groups of the serine. A similar cooperative closure (reminiscent of the folding of proteins) is also displayed with multipeptide solid solutions. For these, the combination of different sequences of amino acids controls the framework's response to the presence of guests in a nonlinear way. This functional control can be compared to the effect of single-point mutations in proteins, in which exchange of single amino acids can radically alter structure and function.