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https://www.readbyqxmd.com/read/28732164/electrochemical-intercalation-of-mg-2-into-anhydrous-and-hydrated-crystalline-tungsten-oxides
#1
Ruocun Wang, Ching-Chang Chung, Yang Liu, Jacob L Jones, Veronica Augustyn
The reversible intercalation of multivalent cations, especially Mg(2+), into a solid-state electrode is an attractive mechanism for next-generation energy storage devices. These reactions typically exhibit poor kinetics due to a high activation energy for interfacial charge-transfer and slow solid-state diffusion. Interlayer water in V2O5 and MnO2 has been shown to improve Mg(2+) intercalation kinetics in non-aqueous electrolytes. Here, the effect of structural water on Mg(2+) intercalation in non-aqueous electrolytes is examined in crystalline WO3 and the related hydrated and layered WO3·nH2O (n = 1, 2)...
July 21, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
https://www.readbyqxmd.com/read/28732010/biofilm-imaging-in-porous-media-by-laboratory-x-ray-tomography-combining-a-non-destructive-contrast-agent-with-propagation-based-phase-contrast-imaging-tools
#2
Maxence Carrel, Mario A Beltran, Verónica L Morales, Nicolas Derlon, Eberhard Morgenroth, Rolf Kaufmann, Markus Holzner
X-ray tomography is a powerful tool giving access to the morphology of biofilms, in 3D porous media, at the mesoscale. Due to the high water content of biofilms, the attenuation coefficient of biofilms and water are very close, hindering the distinction between biofilms and water without the use of contrast agents. Until now, the use of contrast agents such as barium sulfate, silver-coated micro-particles or 1-chloronaphtalene added to the liquid phase allowed imaging the biofilm 3D morphology. However, these contrast agents are not passive and potentially interact with the biofilm when injected into the sample...
2017: PloS One
https://www.readbyqxmd.com/read/28731765/critical-role-of-monoclinic-polarization-rotation-in-high-performance-perovskite-piezoelectric-materials
#3
Hui Liu, Jun Chen, Longlong Fan, Yang Ren, Zhao Pan, K V Lalitha, Jürgen Rödel, Xianran Xing
High-performance piezoelectric materials constantly attract interest for both technological applications and fundamental research. The understanding of the origin of the high-performance piezoelectric property remains a challenge mainly due to the lack of direct experimental evidence. We perform in situ high-energy x-ray diffraction combined with 2D geometry scattering technology to reveal the underlying mechanism for the perovskite-type lead-based high-performance piezoelectric materials. The direct structural evidence reveals that the electric-field-driven continuous polarization rotation within the monoclinic plane plays a critical role to achieve the giant piezoelectric response...
July 7, 2017: Physical Review Letters
https://www.readbyqxmd.com/read/28731743/nonadiabatic-kohn-anomaly-in-heavily-boron-doped-diamond
#4
Fabio Caruso, Moritz Hoesch, Philipp Achatz, Jorge Serrano, Michael Krisch, Etienne Bustarret, Feliciano Giustino
We report evidence of a nonadiabatic Kohn anomaly in boron-doped diamond, using a joint theoretical and experimental analysis of the phonon dispersion relations. We demonstrate that standard calculations of phonons using density-functional perturbation theory are unable to reproduce the dispersion relations of the high-energy phonons measured by high-resolution inelastic x-ray scattering. On the contrary, by taking into account nonadiabatic effects within a many-body field-theoretic framework, we obtain excellent agreement with our experimental data...
July 7, 2017: Physical Review Letters
https://www.readbyqxmd.com/read/28731713/revealing-the-electrochemical-charging-mechanism-of-nano-sized-li2s-by-in-situ-and-operando-x-ray-absorption-spectroscopy
#5
Liang Zhang, Dan Sun, Jun Feng, Elton J Cairns, Jinghua Guo
Lithium sulfide (Li2S) is a promising cathode material for lithium/sulfur (Li/S) cells due to its high theoretical specific capacity (1166 mAh g(-1)) and capability to pair with non-metallic lithium anodes to avoid potential safety issues. However, when used as the cathode a high charging voltage (~ 4 V vs. Li+/Li) is always necessary to activate Li2S in the first charge process, and the voltage profile becomes similar to that of a common sulfur electrode in the following charge processes. In this report, we have prepared an electrode of nano-sphere Li2S particles and investigated its charging mechanism of the initial two charge processes by in-situ and operando X-ray absorption spectroscopy...
July 21, 2017: Nano Letters
https://www.readbyqxmd.com/read/28731698/regiocontrolled-electrosynthesis-of-60-fullerene-bisadducts-photovoltaic-performance-and-crystal-structures-of-c60-o-quinodimethane-bisadducts
#6
Zong-Jun Li, Sisi Wang, Shu-Hui Li, Tao Sun, Wei-Wei Yang, Kazutaka Shoyama, Takafumi Nakagawa, Il Jeon, Xiaoniu Yang, Yutaka Matsuo, Xiang Gao
C60 o-quinodimethane bisadducts (C60(QM)2) are promising electron acceptors for the bulk heterojuction (BHJ) organic solar cells (OSCs). However, previous production of C60(QM)2 often resulted in excessive regioisomers, which were difficult to purify and might consequently obscure the structure-performance study of the organofullerene acceptors. Herein, the electrosynthesis of C60(QM)2 is reported. The reaction exhibits a strong regiocontrol with generation of less regioisomers. Single regioisomers of cis-2, trans-3 and e C60(QM)2 are obtained, and the structures are solved with single crystal X-ray diffraction...
July 21, 2017: Journal of Organic Chemistry
https://www.readbyqxmd.com/read/28731693/isolable-bis-triarylamine-dications-analogues-of-thiele-s-chichibabin-s-and-m%C3%A3-ller-s-hydrocarbons
#7
Gengwen Tan, Xinping Wang
Since the pioneering work by Thiele and Chichibabin, who synthesized the first diradicals bridged by phenylene and biphenylene groups in 1904 and 1907, respectively, numerous efforts have been devoted to synthesizing stable diradicals during the last few decades, and several strategies have been developed to stabilize these highly reactive diradicals. In this Account, we describe the synthesis and characterization of isolable bis(triarylamine) dications, nitrogen analogues of Thiele's, Chichibabin's, and Müller's hydrocarbons, which represent facilely accessible, stable diradicals by replacing carbinyl centers with isoelectronic aminium centers...
July 21, 2017: Accounts of Chemical Research
https://www.readbyqxmd.com/read/28731684/the-binding-mode-of-n-hydroxyamidines-to-indoleamine-2-3-dioxygenase-1-ido1
#8
Ute Friederike Röhrig, Vincent Zoete, Olivier Michielin
Indoleamine 2,3-dioxygenase 1 (IDO1) is an important target in cancer immunotherapy. The most advanced clinical compound, epacadostat (INCB024360), binds to the heme cofactor of IDO1 through a N-hydroxyamidine function. Conflicting binding modes have recently been proposed, reporting iron binding either through the hydroxyamidine oxygen or nitrogen atoms. Here, we use quantum chemical calculations, docking, and QM/MM calculations based on available X-ray data to resolve this issue and to propose a physically meaningful binding mode...
July 21, 2017: Biochemistry
https://www.readbyqxmd.com/read/28731678/stable-and-efficient-cuo-based-photocathode-through-oxygen-rich-composition-and-au-pd-nanostructure-incorporation-for-solar-hydrogen-production
#9
Saeid Masudy-Panah, Roozbeh Siavash Moakhar, Chin Sheng Chua, Ajay Kumar Kushwaha, Goutam Kumar Dalapati
Enhancing stability against photo-corrosion and improving photocurrent response are the main challenges toward the development of cupric oxide (CuO) based photocathodes for solar-driven hydrogen production. In this paper, stable and efficient CuO-photocathodes have been developed using in-situ materials engineering and through gold-palladium (Au-Pd) nanoparticles deposition on the CuO surface. The CuO photocathode exhibits a photocurrent generation of ~3 mA/cm2 at 0V v/s RHE. Time-of-flight secondary ion mass spectrometry (TOF-SIMS) analysis and X-ray spectroscopy (XPS) confirm the formation of oxygen-rich (O-rich) CuO film which demonstrate highly stable photocathode with retained photocurrent of ~90% for 20 minutes...
July 21, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28731587/reversible-pressure-controlled-depolymerization-of-a-copper-ii-containing-coordination-polymer
#10
Jack Kay Clegg, Aidan Brock, Katrina Jolliffe, Simon Parsons, Leonard Lindoy, Peter Tasker, Fraser White
A unique pressure-induced Cu-N bond breaking/bond forming reaction is reported. The variation of pressure on a single crystal of a one-dimensional copper(II)-containing coordination polymer (Cu2L2(1-methylpiperazine)2]n, where H2L is 1,1'-(1,3-phenylene)-bis(4,4-dimethylpentane-1,3-dione)), was monitored using single crystal X-ray diffraction with the aid of a diamond anvil cell. At a very low elevated pressure (~0.05 GPa) a remarkable reversible phase change was observed. The phase change results in the depolymerization of the material through the cleavage and formation of axial Cu-N bonds as well as "ring flips" of individual axially coordinated 1-methylpiperazine ligands...
July 21, 2017: Chemistry: a European Journal
https://www.readbyqxmd.com/read/28731490/lancisi-s-sign-and-central-venous-catheter-tip-position-a-case-report
#11
Valentina Vigo, Piero Lisi, Giuseppe Galgano, Carlo Lomonte
INTRODUCTION: Valvular disease and pulmonary hypertension are common conditions in haemodialysis patients. In presence of tricuspid regurgitation, an increased retrograde blood flow into the right atrium during ventricle systole results in a typical modification of the normal venous waveform, creating a giant c-v wave. This condition clinically appears as a venous palpable pulsation within the internal jugular vein, also known as Lancisi's sign. CASE REPORT: An 83-year-old woman underwent haemodialysis for 9 years...
July 19, 2017: Journal of Vascular Access
https://www.readbyqxmd.com/read/28731343/-roller-wheel-pt-containing-small-molecules-and-the-impact-of-rollers-on-material-crystallinity-electronic-properties-and-solar-cell-performance
#12
Wenhan He, Maksim Y Livshits, Diane A Dickie, Zhen Zhang, Luis E Mejiaortega, Jeffrey J Rack, Qin Wu, Yang Qin
We report the synthesis, characterization and detailed comparison of a series of novel Pt-bisacetylide containing conjugated small molecules possessing an unconventional "roller-wheel" shaped structure that is distinctly different from the "dumbbell" designs in traditional Pt-bisacetylide containing conjugated polymers and small molecules. The relationship between the chemical nature and length of the "rollers" and the electronic and physical properties of the materials are carefully studied by steady state spectroscopy, cyclic voltammetry, differential scanning calorimetry, single-crystal X-ray diffraction, transient absorption spectroscopy, theoretical calculation and device application...
July 21, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28731341/a-2d-coordination-network-that-detects-nitro-explosives-in-water-catalyzes-baylis-hillman-reactions-and-undergoes-unusual-2d%C3%A2-3d-single-crystal-to-single-crystal-transformation
#13
Vivekanand Sharma, Dinesh De, Sanchari Pal, Prithwidip Saha, Parimal K Bharadwaj
The solvothermal reaction of Zn(NO3)2·6H2O and a linear dicarboxylate ligand H2L, in the presence of urotropine in N,N'-dimethylformamide (DMF), gives rise to a new porous two-dimensional (2D) coordination network, {[Zn3(L)3(urotropine)2]·2DMF·3H2O}n (1), with hxl topology. Interestingly, framework 1 exhibits excellent emission properties owing to the presence of naphthalene moiety in the linker H2L, that can be efficiently suppressed by subtle quantity of nitro explosives in aqueous medium. Furthermore, presence of urotropine molecules bound to the metal centers, 1 is found to be an excellent heterogeneous catalyst meant for atom-economical C-C bond-forming Baylis-Hillman reactions...
July 21, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/28731340/chemistry-of-sputter-deposited-lithium-sulfide-films
#14
Michael J Klein, Gabriel M Veith, Arumugam Manthiram
Lithium sulfide (Li2S) is under intense study because it is the insulating discharge product of ultra-high energy density lithium-sulfur (Li-S) batteries and a candidate cathode material for lithium metal-free Li-S cells. In this work, we report the fabrication of an apparatus for sputter deposition of Li2S films ranging in thickness from a few nanometers to several microns at rates over 2 nm min-1. High-temperature annealing of the films is shown to produce crystalline films of high chemical purity Li2S for the first time...
July 21, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28731305/the-role-of-lead-ii-in-nucleic-acids
#15
Joana Palou-Mir, Miquel Barceló-Oliver, Roland K O Sigel
Although lead(II) is naturally not associated with nucleic acids, this metal ions has been applied with DNA and RNA in various contexts. Pb2+ is an excellent hydrolytic metal ion for nucleic acids, which is why it is mainly used as probing agent for secondary structure and to determine metal ion binding sites both in vitro and in vivo. A further application of lead(II) is in structural studies, i.e., NMR, but also in X-ray crystallography, mostly using this heavy metal to solve the phase problem in the latter method...
April 10, 2017: Metal Ions in Life Sciences
https://www.readbyqxmd.com/read/28731299/human-biomonitoring-of-lead-exposure
#16
Katrin Klotz, Thomas Göen
After a chronic exposure, lead accumulates in the human body, especially in bones and teeth. Critical effects of lead affect the nervous system, reproduction, fertility as well as genotoxicity and carcinogenicity [1]. Analyses of lead concentrations in human biological material are performed using inductively coupled plasma mass spectrometry and atomic absorption spectrometry, but also electrochemical methods and X-ray fluorescence spectroscopy. The predominant sample matrices include blood and bone, as well as urine, hair, nail, and saliva...
April 10, 2017: Metal Ions in Life Sciences
https://www.readbyqxmd.com/read/28731261/structural-insights-for-the-borates-with-anion-templated-open-framework-configuration-asymmetric-k2bab16o26-vs-centrosymmetric-k3csb20o32-and-na2m2nb18o30-m-rb-cs-n-ba-pb
#17
Miriding Mutailipu, Min Zhang, Xin Su, Zhihua Yang, Yanna Chen, Shilie Pan
Five new mixed-metal borates, namely, K2BaB16O26, K3CsB20O32, Na2Cs2BaB18O30, Na2Rb2PbB18O30, and Na2Cs2PbB18O30 were synthesized using the high-temperature solution method. Those structures were characterized by single-crystal X-ray diffraction, and the B-O configurations of them are shown to feature complicated three-dimensional (3D) open-framework structures with different types of channels. For all the five compounds, the frameworks can be reduced into four-connected (4-c) uninodal net with sra-, dia- and nbo-type topology by assigning the [B5O10]5- and [B3O7]5- clusters as basic nodes...
July 21, 2017: Chemistry: a European Journal
https://www.readbyqxmd.com/read/28731114/ru-ii-pta-and-mpta-complexes-with-n2-donor-ligands-bipyridyl-and-phenanthroline-and-their-antiproliferative-activities-on-human-multiple-myeloma-cell-lines
#18
Aleksandra Wołoszyn, Claudio Pettinari, Riccardo Pettinari, Gretta Veronica Badillo Patzmay, Anna Kwiecień, Giulio Lupidi, Massimo Nabissi, Giorgio Santoni, Piotr Smoleński
A series of novel ruthenium(ii) 2,2'-bipyridyl (bpy) and 1,10-phenanthroline (phen) derivatives containing PTA (1,3,5-triaza-7-phosphaadamantane) or mPTA (N-methyl-1,3,5-triaza-7-phosphaadamantane cation) have been synthesized and fully characterized. Three types of complexes have been obtained, neutral [Ru(N-N)(PTA)2Cl2] (1, N-N = bpy and 4, N-N = phen), monocationic [Ru(N-N)(PTA)3Cl][Cl] (2, N-N = bpy and 5, N-N = phen) and dicationic [Ru(N-N)(mPTA)Cl2][BF4]2 (3, N-N = bpy and 6, N-N = phen). The solid-state structures of four complexes have been determined by single-crystal X-ray diffraction...
July 21, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/28731105/a-comparative-vuv-absorption-mass-spectroscopy-study-on-protonated-peptides-of-different-size
#19
D Egorov, R Hoekstra, T Schlathölter
The ionization of gas-phase protonated peptides and proteins can induce molecular responses ranging from purely non-dissociative ionization to extensive multifragmentation of the system. In the case of soft X-ray photoionization, a monotonic transition between both regimes occurs in the mass range between 0.5 and 10 kDa. Despite the localized nature of the photoabsorption, excitation energy equilibrates before fragmentation sets in and the transition reflects the increase of the heat capacity with protein size...
July 21, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28731101/selective-molecular-annealing-in-situ-small-angle-x-ray-scattering-study-of-microwave-assisted-annealing-of-block-copolymers
#20
Daniel T W Toolan, Kevin Adlington, Anna Isakova, Alexis Kalamiotis, Parvaneh Mokarian-Tabari, Georgios Dimitrakis, Christopher Dodds, Thomas Arnold, Nick J Terrill, Wim Bras, Daniel Hermida Merino, Paul D Topham, Derek J Irvine, Jonathan R Howse
Microwave annealing has emerged as an alternative to traditional thermal annealing approaches for optimising block copolymer self-assembly. A novel sample environment enabling small angle X-ray scattering to be performed in situ during microwave annealing is demonstrated, which has enabled, for the first time, the direct study of the effects of microwave annealing upon the self-assembly behavior of a model, commercial triblock copolymer system [polystyrene-block-poly(ethylene-co-butylene)-block-polystyrene]...
July 21, 2017: Physical Chemistry Chemical Physics: PCCP
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