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https://www.readbyqxmd.com/read/28546566/a-diastereoselective-synthesis-of-cebranopadol-a-novel-analgesic-showing-nop-mu-mixed-agonism
#1
Anna Fantinati, Sara Bianco, Remo Guerrini, Severo Salvadori, Salvatore Pacifico, Maria Camilla Cerlesi, Girolamo Calo, Claudio Trapella
A diastereoselective synthesis of the title compound as a single E diastereomer has been efficiently accomplished by assembling the featured pyrano-indole scaffold of the spiro[cyclohexane-dihydropyrano[3,4-b]-indole]-amine framework through an oxa-Pictet-Spengler reaction, promoted by a cheap and green Zeolite catalyst. Basic pharmacological experiments demonstrate that Cebranopadol acts as a mixed nociception/orphanin FQ (NOP) and mu (MOP) opioid receptor agonist useful for treatment of chronic pain.
May 25, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28543821/synthesis-of-a-single-crystalline-macroporous-layered-silicate-from-macroporous-utl-type-zeolite-and-its-accelerated-intercalation
#2
Yusuke Asakura, Naoki Kawaura, Yoshiyuki Kuroda, Masakazu Koike, Hiroaki Wada, Atsushi Shimojima, Kazuyuki Kuroda
A single-crystalline macroporous layered silicate was obtained for the first time. Firstly, UTL-type zeolite with macropores was prepared hydrothermally under the presence of acetylene black as a macropore template and the subsequent calcination to remove the template. Double four-membered ring (d4r) units in the UTL framework were selectively dissolved to yield a layered silicate with macropores. Intercalation of tetrabutylammonium ions into the macroporous layered silicate is accelerated if compared with that into the same silicate without macropores, indicating the effectiveness of macropores due to easy diffusion...
May 25, 2017: Chemistry: a European Journal
https://www.readbyqxmd.com/read/28542420/study-on-the-adsorption-of-nitrogen-and-phosphorus-from-biogas-slurry-by-nacl-modified-zeolite
#3
Qunpeng Cheng, Hongxia Li, Yilu Xu, Song Chen, Yuhua Liao, Fang Deng, Jianfen Li
A NaCl-modified zeolite was used to simultaneously remove nitrogen and phosphate from biogas slurry. The effect of pH, contact time and dosage of absorbants on the removal efficiency of nitrogen and phosphate were studied. The results showed that the highest removal efficiency of NH4+-N (92.13%) and PO43--P (90.3%) were achieved at pH 8. While the zeolite doses ranged from 0.5 to 5 g/100 ml, NH4+-N and PO43--P removal efficiencies ranged from 5.19% to 94.94% and 72.16% to 91.63% respectively. The adsorption isotherms of N and P removal with NaCl-modified zeolite were well described by Langmuir models, suggesting the homogeneous sorption mechanisms...
2017: PloS One
https://www.readbyqxmd.com/read/28541290/tailoring-nanoscopic-confines-to-maximize-catalytic-activity-of-hydronium-ions
#4
Hui Shi, Sebastian Eckstein, Aleksei Vjunov, Donald M Camaioni, Johannes A Lercher
Acid catalysis by hydronium ions is ubiquitous in aqueous-phase organic reactions. Here we show that hydronium ion catalysis, exemplified by intramolecular dehydration of cyclohexanol, is markedly influenced by steric constraints, yielding turnover rates that increase by up to two orders of magnitude in tight confines relative to an aqueous solution of a Brønsted acid. The higher activities in zeolites BEA and FAU than in water are caused by more positive activation entropies that more than offset higher activation enthalpies...
May 25, 2017: Nature Communications
https://www.readbyqxmd.com/read/28540721/resonant-gravimetric-identification-of-competitive-adsorption-of-environmental-molecules
#5
Pengcheng Xu, Tao Xu, Haitao Yu, Xinxin Li
Understanding competitive adsorption relationship among various ambient gases is important in adsorbing-material development for capturing environmental harmful gas. For example, environmental interfering factors (e.g., moisture) can affect the competitive gas-molecule adsorption that needs to be clarified. Due to lack of method to quantitatively study dynamic adsorbing process (e.g., real-time counting adsorbed molecule number), it is difficult to reveal the competitive adsorption mechanism. Still using conventional "trial-and-error" method hinders the development of high-performance adsorbing materials, thereby new technology is highly demanded to address the issue...
May 25, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28540551/zif-8-derived-nitrogen-doped-porous-carbon-as-metal-free-catalyst-of-peroxymonosulfate-activation
#6
Wenjie Ma, Yunchen Du, Na Wang, Peng Miao
Nitrogen-doped porous carbon (NPC) is synthesized through a direct pyrolysis of zeolitic imidazolate framework (ZIF)-8 under N2 flow followed by acid washing process. It is found that NPC-800 pyrolyzed at 800 °C can inherit the perfect rhombic dodecahedron morphology of ZIF-8 crystals and achieve the considerable nitrogen-doping content of 15.20%. When NPC-800 is applied as the heterogeneous catalyst in peroxymonosulfate (PMS) activation for the degradation of Rhodamine B (RhB) and phenol, NPC-800 will exhibit its better performance than some conventional transition metal-based oxides and common carbon materials...
May 24, 2017: Environmental Science and Pollution Research International
https://www.readbyqxmd.com/read/28540371/selecting-strong-br%C3%A3-nsted-acid-zeolites-through-screening-from-a-database-of-hypothetical-frameworks
#7
Taku Matsuoka, Laurent Baumes, Naonobu Katada, Abhijit Chatterjee, German Sastre
The database of prospective zeolites () has been screened in search of feasible zeolites with the condition of having at least one strong Brønsted site. Several criteria of zeolite feasibility have been tested using energetic and structural concepts, allowing a fast elimination of unsuitable candidates. Based on improved definitions to count and enumerate rings in zeolites, Brønsted acidity has been assessed in a fast albeit inaccurate way, by calculating a structural descriptor related to ammonia desorption energy...
May 25, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28539702/one-step-synthesis-of-hierarchical-zsm-5-using-cetyltrimethylammonium-as-mesoporogen-and-structure-directing-agent
#8
Lingqian Meng, Brahim Mezari, Maarten G Goesten, Emiel J M Hensen
Hierarchical ZSM-5 zeolite is hydrothermally synthesized in a single step with cetyltrimethylammonium (CTA) hydroxide acting as mesoporogen and structure-directing agent. Essential to this synthesis is the replacement of NaOH with KOH. An in-depth solid-state NMR study reveals that, after early electrostatic interaction between condensed silica and the head group of CTA, ZSM-5 crystallizes around the structure-directing agent. The crucial aspect of using KOH instead of NaOH lies in the faster dissolution of silica, thereby providing sufficient nutrients for zeolite nucleation...
May 9, 2017: Chemistry of Materials: a Publication of the American Chemical Society
https://www.readbyqxmd.com/read/28537379/molecular-rhodium-complexes-supported-on-the-metal-oxide-like-nodes-of-metal-organic-frameworks-and-on-zeolite-hy-catalysts-for-ethylene-hydrogenation-and-dimerization
#9
Varinia Bernales, Dong Yang, Jun Yu, Gamze Gümüşlü, Christopher J Cramer, Bruce C Gates, Laura Gagliardi
Metal-organic frameworks (MOFs) with nodes consisting of zirconium oxide clusters (Zr6) offer new opportunities as supports for catalysts with well-defined, essentially molecular, structures. We used the precursor Rh(C2H4)2(acac) (acac is acetylacetonate) to anchor Rh(I) complexes to the nodes of the MOF UiO-67 and, for comparison, to the zeolite dealuminated HY (DAY). These were characterized experimentally by measurement of catalytic activities and selectivities for ethylene hydrogenation and dimerization in a once-through flow reactor at 298 K and 1 bar...
May 24, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28533030/core-shell-silica-particles-with-dendritic-pore-channels-impregnated-with-zeolite-imidazolate-framework-8-for-high-performance-liquid-chromatography-separation
#10
Qishu Qu, Han Xuan, Kehua Zhang, Xiaoming Chen, Yi Ding, Shaojie Feng, Qin Xu
Metal-organic frameworks (MOFs) have been emerged as promising stationary phases for separations. However, the irregular shapes and wide size distribution of MOF particles have led to the high column backpressure and low column efficiency. We described here a kinetic controlling method to deposit zeolitic imidazolate framework (ZIF-8) onto the pore surface using core-shell silica spheres as support. By varying the volume ratio of N,N-dimethylformamide and methanol, the formation speed of ZIF-8 crystals were greatly suppressed, resulting in the growth of very thin layer (∼3...
May 15, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/28532621/an-experimental-study-on-thermo-catalytic-pyrolysis-of-plastic-waste-using-a-continuous-pyrolyser
#11
Anthony R Auxilio, Wei-Lit Choo, Isha Kohli, Srikanth Chakravartula Srivatsa, Sankar Bhattacharya
A bench scale, two-stage, thermo-catalytic reactor equipped with a continuous feeding system was used to pyrolyse pure and waste plastics. Experiments using five zeolitic and clay-based catalysts of different forms (pellet and powders) and different plastic feedstocks - virgin HDPE, HDPE w1aste and mixed plastic waste (MPW) were compared to the control experiments - pyrolysis without catalyst. Results indicated that the two pelletized catalysts were the most promising for the conditions employed. Of these two, one with higher acidity and surface area was highly selective for the gasoline fraction (C5-C11) giving 80% from the total medium distillate conversion using virgin HDPE as feedstock...
May 19, 2017: Waste Management
https://www.readbyqxmd.com/read/28530401/rational-design-of-mof-nanocarrier-based-co-delivery-system-of-doxorubicin-hydrochloride-verapamil-hydrochloride-for-overcoming-multidrug-resistance-with-efficient-targeted-cancer-therapy
#12
Huiyuan Zhang, Wei Jiang, Ruiling Liu, Jing Zhang, Di Zhang, Zhonghao Li, Yuxia Luan
Conventional organic and inorganic drug nanocarriers suffer from serious drawbacks, such as low drug-storage capacity and uncontrolled release. Moreover, multidrug resistance (MDR) has been one of the primary causes leading to chemotherapy failure for cancers. The main reason of MDR is the overexpressed active efflux transporters such as P-glycoprotein. Here, zeolitic imidazolate framework ZIF-8, as one of the biocompatible metal organic frameworks (MOFs), is reported for the first time as the multidrug carrier to realize the efficient co-delivery of verapamil hydrochloride (VER) as the P-glycoprotein inhibitor as well as doxorubicin hydrochloride (DOX) as an anticancer drug to overcome the MDR in addition to realizing the active targeted ability for an efficient anticancer effect...
May 22, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28525270/two-zeolitic-open-framework-aluminoborates-directed-by-similar-zn-complexes
#13
Qi Wei, Jia-Jia Wang, Jie Zhang, Guo-Yu Yang
Two three-dimensional (3D) zeolitic open-framework aluminoborates (ABOs) [Zn(ma)(en)2][AlB5O10] (1) and [Zn(ma)(en)2][AlB6O11(OH)] (2) (ma = methylamine, en = ethylenediamine) were successfully made under solvothermal conditions, which represent the first examples using similar metal complex (MC) with mixed amines as the structure-directing agents in ABOs. Notice that the central atom in the MC is coordinated by mixed amines is uncommon. However, they exhibit distinctly different structures: 1 crystallizes in a centrosymmetric [Al(B5O10)]n(2n-) zeolitic framework built by pentaborate (B5O10) clusters and AlO4 tetrahedra, exhibiting a 4-connected cag topology, while 2 contains hexaborate (B6O11(OH)) clusters and AlO4 groups, further alternately joined to form a noncentrosymmetric [AlB6O11(OH)]n(2n-) zeolitic framework with 7-/9-, 8-/10-ring helical channels and large 13-ring channels, showing a dia topology...
May 19, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/28521168/ecotoxicity-testing-and-environmental-risk-assessment-of-iron-nanomaterials-for-sub-surface-remediation-recommendations-from-the-fp7-project-nanorem
#14
Rune Hjorth, Claire Coutris, Nhung H A Nguyen, Alena Sevcu, Juliàn Alberto Gallego-Urrea, Anders Baun, Erik J Joner
Nanoremediation with iron (Fe) nanomaterials opens new doors for treating contaminated soil and groundwater, but is also accompanied by new potential risks as large quantities of engineered nanomaterials are introduced into the environment. In this study, we have assessed the ecotoxicity of four engineered Fe nanomaterials, specifically, Nano-Goethite, Trap-Ox Fe-zeolites, Carbo-Iron(®) and FerMEG12, developed within the European FP7 project NanoRem for sub-surface remediation towards a test battery consisting of eight ecotoxicity tests on bacteria (V...
May 13, 2017: Chemosphere
https://www.readbyqxmd.com/read/28520416/experimental-and-theoretical-evaluation-of-the-stability-of-true-mof-polymorphs-explains-their-mechanochemical-interconversions
#15
Zamirbek Akimbekov, Athanassios D Katsenis, G P Nagabhushana, Ghada Ayoub, Mihails Arhangelskis, Andrew J Morris, Tomislav Friscic, Alexandra Navrotsky
We provide the first combined experimental and theoretical evaluation of how differences in ligand structure and framework to-pology affect the relative stabilities of isocompositional (i.e. true polymorph) metal-organic frameworks (MOFs). We used solution calorimetry and periodic DFT calculations to analyze thermodynamics of two families of topologically-distinct polymorphs of zinc zeolitic imidazolate frameworks (ZIFs) based on 2-methyl- and 2-ethylimidazolate linkers, demonstrating a correlation between measured thermodynamic stability and density, and a pronounced effect of the ligand substituent on their stability...
May 18, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28513690/influence-of-the-nature-and-environment-of-manganese-in-mn-bea-zeolites-on-no-conversion-in-selective-catalytic-reduction-with-ammonia
#16
R Baran, L Valentin, J-M Krafft, T Grzybek, P Glatzel, S Dzwigaj
Manganese-containing BEA zeolites, MnxSiBEA (x = 1-4 wt%) and Mn(I.E.)AlBEA, were prepared by a two-step post-synthesis method and a conventional wet ion-exchange, respectively, and applied as catalysts in the selective catalytic reduction of NO with ammonia (NH3-SCR). The physicochemical analysis of zeolite properties by high-energy-resolution fluorescence-detected XANES (HERFD-XANES) and X-ray emission spectroscopy (XES) uncovered that the coordination, geometry and oxidation state of Mn species are strongly related to the preparation method...
May 17, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28511556/performance-and-digestive-function-of-broiler-chickens-given-grit-in-the-diet
#17
B Svihus, K Itani, K Borg, E C Larsson, R Ao, A Sudubilige, B Fuerjiafu, H Liu, H Hetland, G Sanson, B Kierończyk, M Rawski, D Józefiak
1. A series of experiments were carried out to study the effect of grit on broiler performance, gizzard development and fate of grit in the digestive tract. 2. In Experiment 1, performance, gizzard weight and content of grit in the gizzard of broiler chickens given access to granite-type grit was investigated. In Experiment 2, the effect of grit stones on performance and gizzard development was assessed in diets with or without whole wheat. 3. In Experiment 3, the effect of grit in the form of zeolite, granite or marble on gizzard development and digestive tract grinding and passage was studied in diets with or without whole wheat...
May 17, 2017: British Poultry Science
https://www.readbyqxmd.com/read/28508902/non-zeolitic-properties-of-the-dipeptide-l-leucyl-l-leucine-as-a-result-of-the-specific-nanostructure-formation
#18
Marat A Ziganshin, Aisylu S Safiullina, Sufia A Ziganshina, Alexander V Gerasimov, Valery V Gorbatchuk
The non-zeolitic behavior of l-leucyl-l-leucine and its self-organization in solid state and from solutions with the formation of different nanostructures are reported. This dipeptide forms porous crystals, but does not exhibit molecular sieve effects typical of classical zeolites and biozeolites. The specific sorption properties of l-leucyl-l-leucine result from a change in its crystal packing from channel-type to layered-type, when binding strong proton acceptors or proton donors of molecular size greater than 18-20 cm(3) mol(-1)...
May 16, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28507686/gas-confinement-in-compartmentalized-coordination-polymers-for-highly-selective-sorption
#19
Mónica Giménez-Marqués, Néstor Calvo Galve, Miguel Palomino, Susana Valencia, Fernando Rey, Germán Sastre, Iñigo J Vitórica-Yrezábal, Mónica Jiménez-Ruiz, J Alberto Rodríguez-Velamazán, Miguel A González, José L Jordá, Eugenio Coronado, Guillermo Mínguez Espallargas
Discrimination between different gases is an essential aspect for industrial and environmental applications involving sensing and separation. Several classes of porous materials have been used in this context, including zeolites and more recently MOFs. However, to reach high selectivities for the separation of gas mixtures is a challenging task that often requires the understanding of the specific interactions established between the porous framework and the gases. Here we propose an approach to obtain an enhanced selectivity based on the use of compartmentalized coordination polymers, named CCP-1 and CCP-2, which are crystalline materials comprising isolated discrete cavities...
April 1, 2017: Chemical Science
https://www.readbyqxmd.com/read/28505465/isomerization-of-glucose-into-fructose-by-environmentally-friendly-fe-%C3%AE-zeolite-catalysts
#20
Siquan Xu, Lei Zhang, Kehao Xiao, Haian Xia
Herein, the environmentally friendly Fe/β zeolite for glucose isomerization to fructose in aqueous media was reported for the first time. The effects of various reaction conditions including reaction temperature, reaction time, catalyst dosage, etc. on the isomerization reaction over Fe/β zeolite were studied in detail. Under the optimized conditions, yield of fructose higher than 20% were obtained. Moreover, the Fe/β zeolite catalysts were stable and remained constant catalytic activity after five consecutive runs...
May 10, 2017: Carbohydrate Research
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