Trisodium Trimetaphosphimate Monohydrate

The trimetaphosphimate anion (PO2NH)33- in trisodium cyclo-tri--imidotriphosphate monohydrate, Na3(PO2NH)3.H2O, exhibits a chair conformation. Two trimetaphosphimate rings are linked to each other by six N-HO hydrogen bonds forming pairs. These units are interconnected by O-HO hydrogen bonds through water molecules forming columns

Tetraammonium Tetrametaphosphimate Tetrahydrate

The tetrametaphosphimate ring in the title compound, (NH4)4+(PO2NH)4-.4H2O exhibits a chair conformation. The tetrametaphosphimate rings are linked by N-HO bonds forming columns along [100]. These columns are interconnected by O-HO and N-HO hydrogen bonds through water molecules and ammonium ions. All H atoms are involved in hydrogen bonding

Triammonium Trimetaphosphimate Monohydrate

Crystals of triammonium cyclo-tri-μ-imido-triphosphate monohydrate, (NH4)3(PO2NH)3.H20, are composed of three ammonium cations, a trimetaphosphimate anion with a chair conformation and a water molecule per asymmetric unit. A three-dimensional network is formed by N--H...O and O--H...O hydrogen bonds

Controlled modification of the inorganic and organic bricks in an Al-based MOF by direct and post-synthetic synthesis routes

Four new porous CAU-1 derivatives CAU-1–NH2 ([Al4(OH)2(OCH3)4(BDC–NH2)3]·xH2O, BDC–NH22− = aminoterephthalate), CAU-1–NH2(OH) ([Al4(OH)6(BDC–NH2)3]·xH2O), CAU-1–NHCH3 ([Al4(OH)2(OCH3)4(BDC–NHCH3)3]·xH2O) and CAU-1–NHCOCH3 ([Al4(OH)2(OCH3)4(BDC–NHCOCH3)3]·xH2O) all containing an octameric [Al8(OH)4+y(OCH3)8−y]12+ cluster, with y = 0–8, have been obtained by MW-assisted synthesis and post-synthetic modification. The inorganic as well as the organic unit can be modified. Heteronuclear 1H–15N, 1H–13C and homonuclear 1H–1H connectivities determined by solid-state NMR spectroscopy prove the methylation of the NH2 groups when conventional heating is used. Varying reaction times and temperatures allow controlling the degree of methylation of the amino groups. Short reaction times lead to non-methylated CAU-1 (CAU-1–NH2), while longer reaction times result in CAU-1–NHCH3. CAU-1–NH2 can be modified chemically by using acetic anhydride, and the acetamide derivative CAU-1–NHCOCH3 is obtained. Thermal treatment permits us to change the composition of the Al-containing unit. Methoxy groups are gradually exchanged by hydroxy groups at 190 °C in air. Solid-state NMR spectra unequivocally demonstrate the presence of the amino groups, as well as the successful post-synthetic modification. Furthermore 1H–1H correlation spectra using homonuclear decoupling allow the orientation of the NHCOCH3 groups within the pores to be unravelled. The influence of time and temperature on the synthesis of CAU-1 was studied by X-ray powder diffraction, elemental analyses, and 1H liquid-state NMR and IR spectroscopy

Vibrational analysis of Ag3(PO2NH)3, Na3(PO2NH)3.H2O, Na3(PO2NH)3.4H2O, [C(NH2)3]3(PO2NH)3.H2O and (NH4)4(PO2NH)4.4H2O

FT IR and FT Raman spectra of Ag3(PO2NH), (Compound I), Na3(PO2NH)3.H2O (Compound II), Na3(PO2NH)3.4H2O (Compound III), [C(NH2)3]3(PO2NH)3.H2O (Compound IV) and (NH4)4(PO2NH)4.4H2O (Compound V) are recorded and analyzed on the basis of the anions, cations and water molecules present in each of them. The PO2NH− anion ring in compound I is distorted due to the influence of Ag+ cation. Wide variation in the hydrogen bond lengths in compound III is indicated by the splitting of the v2 and v3 modes of vibration of water molecules. The NH4 ion in compound V occupies lower site symmetry and exhibits hindered rotation in the lattice. The correlations between the symmetric and asymmetric stretching vibrations of P-N-P bridge and the P-N-P bond angle have also been discussed

New multifunctional sulfonato-containing metal phosphonates proton conductors

Anchoring of acidic functional groups to organic linkers acting as ligands in metal phosphonates has been demonstrate to be a valid strategy to develop new proton conductor materials, which exhibit tunable properties and are potentially applicable to proton exchange membranes, such as those used in PEMFCs [1,2]. In this work, the structural and proton conductivity properties of several families of divalent and trivalent metal amino-sulfophosphonates are presented. The chosen ligand, (H2O3PCH2)2-N-(CH2)2-SO3H, was reacted with the appropriate metal salt using highthrough-put screening and/or microwave-assisted synthesis. Different crystal structures haven been solved displaying a variety of metal ligand coordination modes, in whose frameworks acidic groups contribute to create strong H-bond networks; together with lattice and bound water molecules. Proton conductivity values oscillate between 10-4 and 10-2 S.cm-1, at 80 ºC and 95 % relative humidity, most of them showing activation energies characteristic of a Grotthuss-type proton transport mechanism.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. MINECO: MAT2016-77648-R Junta de Andalucía: P-12-FQM-1656 y FQM-11

Posterior pelvic ring fractures: Closed reduction and percutaneous CT-guided sacroiliac screw fixation

Purpose: To assess the midterm results of closed reduction and percutaneous fixation (CRPF) with computed tomography (CT)-guided sacroiliac screw fixation in longitudinal posterior pelvic ring fractures. Methods: Thirteen patients with 15 fractures were treated. Eleven patients received a unilateral, two a bilateral, screw fixation. Twenty-seven screws were implanted. Continuous on-table traction was used in six cases. Mean radiological follow-up was 13 months. Results: Twenty-five (93%) screws were placed correctly. There was no impingement of screws on neurovascular structures. Union occurred in 12 (80%), delayed union in 2 (13%), and nonunion in 1 of 15 (7%) fractures. There was one screw breakage and two axial dislocations. Conclusion: Sacroiliac CRPF of longitudinal fractures of the posterior pelvic ring is technically simple, minimally invasive, well localized, and stable. It should be done by an interventional/surgical team. CT is an excellent guiding modality. Closed reduction may be a problem and succeeds best when performed as early as possibl

The flexibility of modified-linker MIL-53 materials

The flexibility of eight aluminium hydroxo terephthalates [Al(OH)(BDC–X)]·n(guest) (BDC = 1,4-benzene-dicarboxylate; X = –H, –CH3, –Cl, –Br, –NH2, –NO2, –(OH)2, –CO2H) crystallising in the MIL-53-type structure was investigated upon thermal dehydration of as-made samples, superhydration and methanol adsorption/desorption using in situ powder X-ray diffraction (PXRD). Profile fitting was used to determine lattice parameters as a function of time and/or temperature to describe their structural evolution. It has thus been shown that while methanol vapour adsorption induces an opening of all the modified frameworks, except the –NH2 material, superhydration only leads to open structures for Al-MIL-53–NO2, –Br and –(OH)2. All the MIL-53 solids, except Al-MIL-53–(OH)2 are present in the open structures upon thermal dehydration. In addition to the exploration of the breathing behavior of this MIL-53 series, the issue of disorder in the distribution of the functional groups between the organic linkers was explored. As a typical illustration, density functional theory calculations were carried out on different structures of Al-MIL-53–Cl, in which the distribution of –Cl within two adjacent BDC linkers is varied. The results show that the most energetically stable configuration leads to the best agreement with the experimental PXRD pattern. This observation supports that the distribution of the selected linker substituent in the functionalised solid is governed by energetics and that there is a preference for an ordering of this arrangement

Metal-Organic Frameworks in Germany: from Synthesis to Function

Metal-organic frameworks (MOFs) are constructed from a combination of inorganic and organic units to produce materials which display high porosity, among other unique and exciting properties. MOFs have shown promise in many wide-ranging applications, such as catalysis and gas separations. In this review, we highlight MOF research conducted by Germany-based research groups. Specifically, we feature approaches for the synthesis of new MOFs, high-throughput MOF production, advanced characterization methods and examples of advanced functions and properties

A breathing zirconium metal-organic framework with reversible loss of crystallinity by correlated nanodomain formation

The isoreticular analogue of the metal-organic framework UiO-66(Zr), synthesized with the flexible trans-1,4-cyclohexanedicarboxylic acid as linker, shows a peculiar breathing behavior by reversibly losing long-range crystalline order upon evacuation. The underlying flexibility is attributed to a concerted conformational contraction of up to two thirds of the linkers, which breaks the local lattice symmetry. X-ray scattering data are described well by a nanodomain model in which differently oriented tetragonal-type distortions propagate over about 7-10 unit cells