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The environmentally benign metal-organic framework (MOF) CUK-1 based on 2,4-pyridine dicarboxylate has been prepared for the first time using Mn(II) as the inorganic node and water as the only solvent. Mn-CUK-1 shows reversible and efficient capture of H

Porous nanoscale carbonaceous materials are widely employed for catalysis, separations, and electrochemical devices where device performance often relies upon specific and well-defined regular feature sizes. The use of block polymers as templates has enabled affordable and scalable production of diverse porous carbons. However, popular carbon preparations use equilibrating micelles which can change dimensions in response to the processing environment. Thus, polymer methods have not yet demonstrated carbon nanomaterials with constant average template diameter and tailored wall thickness. In contrast, persistent micelle templates (PMTs) use kinetic control to preserve constant micelle template diameters, and thus PMT has enabled constant pore diameter metrics. With PMT, the wall thickness is independently adjustable via the amount of material precursor added to the micelle templates. Previous PMT demonstrations relied upon thermodynamic barriers to inhibit chain exchange while in solution, followed by rapid evaporation and cross-linking of material precursors to mitigate micelle reorganization once the solvent evaporated. It is shown here that this approach, however, fails to deliver kinetic micelle control when used with slowly cross-linking material precursors such as those for porous carbons. A new modality for kinetic control over micelle templates, glassy-PMTs, is shown using an immobilized glassy micelle core composed of polystyrene (PS). Although PS based polymers have been used to template carbon materials before, all prior reports included plasticizers that prevented kinetic micelle control. Here the key synthetic conditions for carbon materials with glassy-PMT control are enumerated, including dependencies upon polymer block selection, block molecular mass, solvent selection, and micelle processing timeline. The use of glassy-PMTs also enables the direct observation of micelle cores by TEM which are shown to be commensurate with template dimensions. Glassy-PMTs are thus robust and insensitive to material processing kinetics, broadly enabling tailored nanomaterials with diverse chemistries.

A combined experimental and theoretical study of H

STUDY DESIGN: Prospective longitudinal study of novel growth modulation system for early adolescent idiopathic scoliosis (AIS), consecutive case series from first human use to study endpoint at skeletal maturity, fusion, or five years postoperation. OBJECTIVES: Determine adverse events and curvature changes to end of study; examine factors most likely to explain variability in curve changes. SUMMARY OF BACKGROUND DATA: Pilot clinical safety study was performed under US Food and Drug Administration (FDA) Investigational Device Exemption (IDE). Safety and radiographic results were previously reported to 24 months postoperation. METHODS: Subjects with early AIS underwent thoracoscopic placement of titanium clip-screw devices designed to modify growth asymmetrically. Eligibility was based on high risk of progression to 50°: single major thoracic curve 25°–40°, Risser 0, open triradiate cartilages, and premenarchal if female. Six subjects, the maximum allowed, enrolled. Adverse events (AEs), clinical outcomes, and curvatures were systematically collected. Disc heights, vertebral heights, and implant-bone contact areas were assessed. RESULTS: Consecutive subjects enrolled, aged 12.1 years (±1.7), three were female. AEs from two to five years postoperation included deformity changes leading to a second surgery in three patients: two for posterior spinal fusion, and one for thoracoscopic removal of half the implants for overcorrection. One patient, whose curve exceeded 50° at 18 years, did not choose fusion. Major thoracic curves were 34° (±3°) preoperatively and 42° (±20°) at end of study. CONCLUSIONS: In a study of spine growth modulation in patients with early AIS with high risk of progression, at skeletal maturity or five years postoperation, major thoracic curves of half progressed to >50°, whereas curves of the other half remained

We demonstrate a simple and generalizable method for the one pot, in situ formation of bimetallic metal–organic framework (MOF) materials decorated with crystallographically defined, low-valent metal sites. Solvothermal reactions between poly(carboxylated) aryl(phosphine) ligands and mixtures of higher- and lower-valent metal precursors achieves concomitant P–M complexation and MOF formation via metal–carboxylate network bonding. This method is demonstrated in the preparation of two new phosphine coordination materials, PCM-107 and PCM-74, which feature Ar3P–AuX (X = Cl, Br) and chelated PN–Cu2I2–PN units as the MOF building blocks, respectively. PCM-107 is an active catalyst for alkyne hydroaddition, while PCM-74 shows promise for the crystallization of MOFs bearing kinetically favored isomers.

The highly unfavorable thermodynamics of direct aluminum hydrogenation can be overcome by stabilizing alane within a nanoporous bipyridine-functionalized covalent triazine framework (AlH3 @CTF-bipyridine). This material and the counterpart AlH3 @CTF-biphenyl rapidly desorb H2 between 95 and 154 °C, with desorption complete at 250 °C. Sieverts measurements, 27 Al MAS NMR and 27 Al{1 H} REDOR experiments, and computational spectroscopy reveal that AlH3 @CTF-bipyridine dehydrogenation is reversible at 60 °C under 700 bar hydrogen, >10 times lower pressure than that required to hydrogenate bulk aluminum. DFT calculations and EPR measurements support an unconventional mechanism whereby strong AlH3 binding to bipyridine results in single-electron transfer to form AlH2 (AlH3 )n clusters. The resulting size-dependent charge redistribution alters the dehydrogenation/rehydrogenation thermochemistry, suggesting a novel strategy to enable reversibility in high-capacity metal hydrides.

The tetrahedral zwitterion of tetrakis(p-carboxyphenyl) phosphonium is structurally analogous to a family of ligands with C or Si cores that have found great utility in the preparation of stable MOFs. However, the central P(V)+ core in this molecule reduces the formal ligand charge, resulting in a PR43− tetra(carboxylate) species. This new strategy allows for the formation of lighter MOFs by incorporation of less metal, which cannot be accessed using conventional ligands. The phosphonium zwitterion is stable under hydrothermal synthesis conditions; it spontaneously crystallizes from hot DMF to give a metal-free and infinitely porous ionic hydrogen-bonded organic framework, which is stable in water and organic solvents. We demonstrate how direct hydrothermal treatment of the ionic framework in the presence of In(NO3)3 yields a new charge-neutral In(III) MOF with diamondoid topology. By comparison, solvothermal reaction in the presence of Mg(NO3)2 yields a chemically-robust MOF with permanent 3D porosity. The Mg(II)-based MOF displays water adsorption properties with an estimated ΔHads of −63.5 kJ mol−1 and a maximum uptake of 38.9 wt% at 30 °C. This exceptionally stable material also showed highly reversible H2S sorption with a capacity of ∼8 mmol g−1, and solvent-triggered H2S release.

A large-pore version of Mg-CUK-1, a water-stable metal-organic framework (MOF) with 1-D channels, was synthesized in basic water. Mg-CUK-1L has a BET surface area of 2896 m2 g-1 and shows stark selectivity for CO2 sorption over N2, O2, H2, and CH4. It displays reversible, multistep gated sorption of CO2 below 0.33 atm. The dehydrated single-crystal structure of Mg-CUK-1L confirms retention of the open-channel structure. The MOF can be loaded with organic molecules by immersion in hot melts, providing single crystals suitable for X-ray diffraction. trans-Azobenzene fills the channels in a 2 × 2 arrangement. Solid-state UV-vis spectroscopy reveals that azobenzene molecules undergo reversible trans-cis isomerization, despite being close-packed; this surprising result is confirmed by DFT-simulated UV-vis spectra.

PCM-101 is a phosphine coordination material comprised of tris(p-carboxylato)triphenylphosphine and secondary pillaring groups coordinated to [M3 (OH)]5+ nodes (M=Co, Ni). PCM-101 has a unique topology in which R3 P: sites are arranged directly trans to one another, with a P⋅⋅⋅P separation distance dictated by the pillars. Post-synthetic coordination of soft metals to the P: sites proceeds at room temperature to provide X-ray quality crystals that permit full structural resolution. Addition of AuCl groups forces a large distortion of the parent framework. In contrast, CuBr undergoes insertion directly between the trans-P sites to form dimers that mimic solution-phase complexes, but that are geometrically strained due to steric pressure exerted by the MOF scaffold. The metalated materials are active in heterogeneous hydroaddition catalysis under mild conditions, yielding different major products compared to their molecular counterparts.

Controlled partial decomposition of 2-selenonicotinic acid in the presence of Co2+ or Ni2+ resulted in the in situ formation of an unusual MOF based on triselenane ligands (RSeSeSeR) coordinated to M2+ centers as NSeN-pincers. Post-synthetic oxidation by treatment with aqueous H2O2 facilitates its solid-state conversion into a RSeO2− molecular coordination complex, which was tracked via powder X-ray diffraction studies and by single-crystal structural resolution of the final product.

International audience; Kinetic CO2 adsorption measurements in the water-stable and permanently microporous Metal–organic framework material, Mg-CUK-1, reveal a 1.8-fold increase in CO2 capture from 4.6 wt% to 8.5 wt% in the presence of 18% relative humidity. Thermodynamic CO2 uptake experiments corroborate this enhancement effect, while grand canonical Monte Carlo simulations also support the phenomenon of a humidity-induced increase in the CO2 sorption capacity in Mg-CUK-1. Molecular simulations were implemented to gain insight into the microscopic adsorption mechanism responsible for the observed CO2 sorption enhancement. These simulations indicate that the cause of increasing CO2 adsorption enthalpy in the presence of H2O is due to favorable intermolecular interactions between the co-adsorbates confined within the micropores of Mg-CUK-1.

The new ligand tris(p-carboxyphenylethynyl)phosphine (P{C[triple bond, length as m-dash]CC6H4-4-CO2H}3) was used to synthesize a permanently porous Mn(ii)-based acetylenic phosphine coordination material, PCM-48. This triply-interpenetrated MOF contains 1-D microchannels that are decorated with electron-rich and adsorbate-accessible acetylenic moieties and phosphine lone pairs. PCM-48 has a moderate room-temperature C2H2 adsorption capacity (25.54 cm3 g-1) and displays high separation selectivities for C2H2 over CH4 (C2H2/CH4 = 23.3), CO2 (C2H2/CO2 = 4.3), and N2 (C2H2/N2 = 76.9) at 296 K.

International audience; Mg-CUK-1, an ecologically friendly material synthesised in water is found to be a high-capacity, highly reversible adsorbent for acidic gases including H2S and CO2. Furthermore, Mg-CUK-1 is demonstrated to retain long-range crystallinity upon sorption cycling; its sorption performance is maintained over multiple cycles, even in the presence of high relative humidity (95%). Reversible H2S adsorption by Mg-CUK-1 is rare among MOFs studied for this purpose to date. The joint experimental and computational studies presented here show that Mg-CUK-1 is an effective solid adsorbent for applications in the field of acid gas capture, an application that is highly relevant for the purification of many industrial gas streams.

ACM-1 is the first example of an organoarsine metal–organic framework (MOF), prepared using a new pyridyl-functionalized triarylarsine ligand coordinated to Ni(II) nodes. ACM-1 has micropores that are decorated with cis-diarsine coordination pockets. Postsynthetic metalation of ACM-1 with AuCl under facile conditions studied by single-crystal X-ray diffraction reveals the installation of dimeric Au2Cl2 complexes via the formation of As–Au bonds. The Au(I) dimers display exceptionally short aurophilic bonds (2.76 A) induced by the rigidity of the MOF, which acts as a unique solid-state ligand.

Study Design Prospective pilot clinical safety study of novel treatment, consecutive case series from first human use in patients with early adolescent idiopathic scoliosis (AIS). Objective The primary purpose was to determine the initial safety of a titanium clip-screw implant system for spine growth modulation. The secondary aim was to document curvatures to 2 years postoperatively. Summary of Background Data Spinal growth modulation was documented in preclinical studies. A prospective pilot clinical safety study was then performed under a Food and Drug Administration (FDA) Investigational Device Exemption (IDE) ( www.clinicaltrials.gov Identifier: NCT01465295 ). Methods Six subjects with early AIS underwent thoracoscopic placement of titanium clip-screw devices. Eligibility criteria included only patients at high risk for progression to 50°: single major thoracic curve 25°–40°, age ≥10 years, skeletally immature (Risser 0 plus open triradiate cartilages), and if female, premenarchal. Adverse events (AEs), clinical outcomes, and radiographic measures were documented using Good Clinical Practices. Results Six consecutive subjects were enrolled, three females and three males aged 12.1 years (±1.7). AEs included one that was device related—mild device migration at 18 months in the most rapidly progressive curve. Procedure-related AEs were mostly pulmonary. A chylous effusion that met the clinical protocol definition of a serious AE resolved after minimally invasive interventions. Major thoracic curves were 34° (±3°) preoperatively and 38° (±18°) at two years (intrasubject change, 4° ± 18°). At 24 months, curves in 3 patients were >45° and 3 were Conclusions A spine growth modulation system undergoing study under an FDA IDE was determined to be safe. Variability in curve response to the implant was high, ranging from progression to correction. Investigational approval was granted by the US FDA for the next cohort of 30 subjects.

Spinal growth modification using a thoracoscopically implanted clip-screw construct has been under investigation since 1997. Preclinical to clinical studies are described, including design objectives, theoretical advantages, mechanical function, clinical safety, surgical technique, and early radiographic and quality of life results. Most recently, a titanium construct and custom surgical instruments have been tested prospectively from first human use in a US FDA-approved clinical trial under an Investigational Device Exemption (IDE) (IRB approved) for treatment of late juvenile and early adolescent idiopathic thoracic scoliosis. Eligibility criteria were designed to include only those subjects at very high risk of curve progression to >50° by published criteria. The first six children who met the eligibility criteria assented, with parental consent. In the longest follow-up of the cohort to date, mean curvatures at 18 months had not increased from preoperative values. Individual longitudinal results were variable and included one subject who required instrumentation and fusion. Proof of concept in humans, however, was demonstrated in a child whose curvature was corrected by 71 % at 1 year. The corrected thoracic curve, coupled with a simultaneously developing compensatory lumbar curve, started to decrease coronal alignment. By 21 months, both lumbar curvature and coronal plane alignment improved. This time course suggests that the method may not only arrest thoracic curve progression, but may also alter the progression of compensatory curvatures. Implant design factors relative to anatomical dimensions and physiologic loading may be critical to consistent curve arrest. Longer-term results and a larger cohort are essential to determine the device performance. If successful, this minimally invasive thoracoscopic surgical approach and clip-screw construct may become a standard of care for late juvenile and early adolescent idiopathic scoliosis. The device is approved for use in the European Union (CE Mark) for the labeled indications. The pivotal-phase IDE clinical trial is approved by the US FDA.

The effect of pH on the spectral and redox properties of model GFP synthetic chromophores (Cros) in a universal buffer system was investigated. The Cro hydroxy-derivatives demonstrated a Nernst-type electrochemical dependence of the anodic potential within the pH 2-8 range. Analogous studies on various fluorescent proteins were unsuccessful.