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    6541 results match your criteria Chemphyschem : a European journal of chemical physics and physical chemistry[Journal]

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    Approach to the mechanism of hydrogen evolution electrocatalyzed by a model Co clathrochelate: A theoretical study by Density Functional Theory.
    Chemphyschem 2018 Jun 20. Epub 2018 Jun 20.
    Universite Paris-Sud Faculte des Sciences d'Orsay, FRANCE.
    The hydrogen evolution reaction (HER) is the focus of much attention by the scientific community because of the increasing energetic demands of modern society for clean and renewable energy sources. Molecular complexes of 3d-transition metals, such as cobalt, are potential alternative candidates to platinum for the HER in acidic media. Among these, cage complexes such as tris-dioximate metal clathrochelates have shown high HER catalytic properties. Read More

    In-situ complex with by-product HCl and release chloride ions to dissolve aramid.
    Chemphyschem 2018 Jun 20. Epub 2018 Jun 20.
    Sichuan University, College of Polymer Science and Engineering, No.24 South Section 1, Yihuan Road,, chengdu, CHINA.
    Because of the strong hydrogen-bond interaction among macromolecular chains, addition of chloride salts is generally needed to offer Cl- ions for dissolution of aromatic polyamides. In this paper, poly-(benzimidazole-terephthalamide) which complexed with by-product HCl during polymerization (PABI-HCl) was prepared and imidazole compound as cosolvent was added into dimethylacetamide (DMAc) to dissolve PABI-HCl. Due to stronger affinity to protons, imidazole compound could in-situ complex with HCl of PABI-HCl and form imidazolium hydrochloride. Read More

    Tuning the Properties of Periodic Mesoporous Organosilica Films for Low-k Application by Gemini Surfactants.
    Chemphyschem 2018 Jun 20. Epub 2018 Jun 20.
    Kapeldreef 75, Leuven, 3001, Belgium.
    Periodic mesoporous organosilica (PMO) thin films were synthesized by evaporation-induced self-assembly of 1,2-bis(triethoxysilyl)ethane and an ionic Gemini 16-12-16 surfactant under acidic conditions. The films were characterized by Fourier-transform infrared spectroscopy, grazing-incidence small-angle X-ray scattering, ellipsometric porosimetry, impedance measurements, and nanoindentation. The ease of control of the packing parameter in Gemini surfactants makes the PMO film templated by a Gemini an exciting first step towards small pore size PMO films with engineered mesostructures. Read More

    Direct correlation between adsorption energetics and nuclear spin relaxation in liquid-saturated catalyst material.
    Chemphyschem 2018 Jun 20. Epub 2018 Jun 20.
    The University of Manchester, School Chemical Engineering and Analytical Science, The Mill, Sackville Street, M13 9PL, Manchester, UNITED KINGDOM.
    The ratio of NMR relaxation time constants T1/T2 provides a non-destructive indication of the relative surface affinities exhibited by adsorbates within liquid-saturated mesoporous catalysts. In the present work we provide supporting evidence for the existence of a quantitative relationship between such measurements and adsorption energetics. As a prototypical example with relevance to green chemical processes we examine and contrast the relaxation characteristics of primary alcohols and cyclohexane within an industrial silica catalyst support. Read More

    Unveiling the Dual Emission Photo-Deactivation Mechanism of a Neutral Heteroleptic Iridium (III) Complex.
    Chemphyschem 2018 Jun 19. Epub 2018 Jun 19.
    School of Chemistry and Chemical Engineering, Southwest University, Chongqing, China, 400715.
    In this article, the photo-deactivation mechanism of dual emission of a neutral iridium (III) complex is explored by using density function theory (DFT) and time-dependent density function theory (TD-DFT) calculations. To explore the phosphorescence quantum yield of the iridium (III) complex, the radiative decay constant of each emission excited state was computed by TD-DFT calculations, including spin-orbit coupling (SOC). In these calculations, factors such as the transition dipole moments, energy gaps, and SOC elements between the emission states and singlet excited states are taken into account in the evaluation of the radiative decay constants. Read More

    Ag+ and Polycyclic Aromatic Hydrocarbons: A Comprehensive Theoretical Study of Interactions.
    Chemphyschem 2018 Jun 19. Epub 2018 Jun 19.
    Illinois Institute of Technology, Department of Chemistry, 1301 S. Dearborn Street, Life Science Building, Room 390, 60616, Chicago, UNITED STATES.
    The first comprehensive and systematic theoretical exploration of the bonding nature and energetics of the interactions between Ag(I) cation and a wide set of pi-ligands was accomplished. Application of two energy decomposition schemes based on different ideas, namely, NBO-NEDA and EDA-NOCV, allowed shedding light on the nature of the bonding and its energetics. Importantly, our results unambiguously indicate that reliable results can be obtained only if using more than one theoretical approach. Read More

    Ternary Polymeric Composites Exhibiting Bulk and Surface Quadruple-Shape Memory Properties.
    Chemphyschem 2018 Jun 19. Epub 2018 Jun 19.
    Bucknell University, Chemical Engineering, One Dent Drive, 17837, United States, 17837, Lewisburg, UNITED STATES.
    We report the design and characterization of a multiphase quadruple shape memory composite capable of switching between 4 programmed shapes, three temporary and one permanent. Our approach combined two previously reported fabrication methods by embedding an electrospun mat of PCL in a miscible blend of epoxy monomers and PMMA as a composite matrix. As epoxy polymerization occurred the matrix underwent phase separation between the epoxy and PMMA materials. Read More

    Protein-Protein Interfaces Probed by Methyl-Labeling and Proton-Detected Solid-State NMR Spectroscopy.
    Chemphyschem 2018 Jun 19. Epub 2018 Jun 19.
    FMP Berlin, Molecular Biophysics, Robert-Rössle-Str. 10, 13125, Berlin, GERMANY.
    Proton detection and fast magic-angle spinning have advanced biological solid-state NMR, allowing for the backbone assignment of complex protein assemblies with high sensitivity and resolution. However, so far no method has been proposed to detect intermolecular interfaces in these assemblies by proton detection. Here, we introduce a concept based on methyl-labeling that allows for the assignment of these moieties and for the study of protein-protein interfaces at atomic resolution. Read More

    CdSeTe@CdS@ZnS Quantum-Dot-Sensitized Macroporous Tio Film: A Multisignal-Amplified Photoelectrochemical Platform.
    Chemphyschem 2015 Sep;16(13):2826-2835
    State Key Laboratory of Analytical Chemistry for Life Science, Collaborative Innovation Center of Chemistry for Life Science, School of Chemistry & Chemical Engineering, Nanjing University, Nanjing 210093(P. R. China).
    A macroporous TiO film (M-TiO ), which was prepared by burning off the polystyrene microsphere (PS) template from a PS/TiO composite film, can provide a large active surface, improve electron-transport performance, and increase the photocurrent. Furthermore, core-shell-shell CdSeTe@CdS@ZnS quantum dots (QDs) were introduced to sensitize the M-TiO film, which can efficiently broaden the absorption spectra range, separate and transfer charge carriers, reduce recombination loss, and improve photovoltaic response, with a sensitization shell of CdS and a passivation shell of ZnS. A multisignal-amplified photoelectrochemical platform was fabricated by further modifying this film with a combination of biotin-DEVD-peptide (Biotin-Gly-Asp-Gly-Asp-Glu-Val-Asp-Gly-Cys) (which is specifically cleaved by caspase-3) and streptavidin-labeled alkaline phosphatase (SA-ALP). Read More

    Multiple-Site SO -Capture Ionic Liquids with Nearly Uniform Site Performance.
    Chemphyschem 2015 Sep 10;16(13):2854-2860. Epub 2015 Aug 10.
    Department of Applied chemistry, School of Science, Xi'an Jiaotong University, Xi'an, Shaanxi, 710049 (China).
    We propose a series of azolium poly(azolyl)borate ionic liquids (ILs) for reversible SO capture. Density functional calculations demonstrate that the designed borate anions can strongly bond to SO at multiple sites with nearly uniform binding energies. Thus, as well as high overall uptakes, the ILs can achieve much higher effective uptakes (the uptake difference between absorption and desorption conditions) than existing SO -capture reagents. Read More

    Fingerprint Stimulated Raman Scattering Imaging Reveals Retinoid Coupling Lipid Metabolism and Survival.
    Chemphyschem 2018 Jun 17. Epub 2018 Jun 17.
    Boston University, ECE, 8 Saint Mary's Street, 02215, Boston, UNITED STATES.
    Retinoids play critical roles in development, immunity and lipid metabolism, and their deficiency leads to various human disorders. Yet, tools for sensing retinoids in vivo are lacking, which limits the understanding of retinoid distribution, dynamics and functions in living organisms. Here, using hyperspectral stimulated Raman scattering microscopy, we discover a previously unknown cytoplasmic store of retinoids in Caenorahbditis elegans. Read More

    Helicenes as Molecular Tweezers in the Formation of Cation-π Complexes. Bonding and Circular Dichroism Properties from Relativistic DFT Calculations.
    Chemphyschem 2018 Jun 14. Epub 2018 Jun 14.
    Helicene ligands possess a unique helicoidal π-conjugated framework providing high optical rotation values, where a growing interest in helicene derivatives as building blocks has triggered the development of simple strategies to tune their properties. In this context, here we evaluated the formation of cation-π complexes derived from [6]- and [7]helicene, involving Sn2+, Cd2+ and In+, besides of Ag+, which appears as a plausible modification of such helicoidal structure. The nature of the cation-π interaction in the studied helicene complexes exhibits a covalent character, accounting for ligand π-donation to 5s and 5p empty orbitals of the involved cations. Read More

    Boron centres allow design, control and systematic tuning of neutral homoaromatics for functionalization purposes.
    Chemphyschem 2018 Jun 13. Epub 2018 Jun 13.
    University of Sussex, Department of Chemistry, Falmer, BN1 9QJ, Brighton, UNITED KINGDOM.
    Homoaromatic compounds are currently viewed more as an interesting novelty with little to no practical application. Based on calculations within density functional theory, we show that the unique charge redirection properties of tricoordinate boron, along with it being isolobal to a carbocation allow for a larger range of two-electron donors to be utilized, leading to the rational design of homoaromatic compounds better suited to functionalization. Among others, these compounds show a strong dependency on the relative positioning of the hetero-atoms within the ring system, a modulation control rendered possible by the insertion of the boron centres. Read More

    Polarization gratings spontaneously formed by the helical Twist-Bend Nematic phase.
    Chemphyschem 2018 Jun 12. Epub 2018 Jun 12.
    University of Warsaw, Department of Chemistry, Zwirki i Wigury 101, .., 02-089, Warsaw, POLAND.
    Spontaneous formation of polarization gratings by liquid crystals made of bent dimeric molecules is reported. The grating is formed within the temperature range of the twist bend modulated nematic phase, NTB, without the necessity to pattern the cell surfaces, therefore the modulated nematic phase is a promising candidate for low-cost modulators and beam steering devices, the polarization properties of which depend on temperature. In addition, the study of the diffracted light properties turns out to be a sensitive measuring technique for determination of the 3D spatial variation of the optic axis in the cell. Read More

    Thermoviscosifying Smart Polymers for Oil and Gas Production: State of the Art.
    Chemphyschem 2018 Jun 11. Epub 2018 Jun 11.
    Sichuan University, Polymer Research Institute, No. 24, South Section 1, Yihuan Road, 610065, Chengdu, CHINA.
    Water-soluble polymers have been extensively used in all sections of oil and gas upstream industry, but the inherent thermothinning behaviours limited their applications in harsh environment. To address this issue, thermoviscosifying (or "thermothickening") polymers (TVPs) whose aqueous solution viscosity automatically increase upon increasing temperature was introduced early 1990s. This review started with recalling the background for developing such smart materials, followed by demonstrating the mechanism of thermothickening. Read More

    Mechanochemically Processed Nd-Fe-Co-Cr-B Nanoparticles with High Coercivity and Reduced Spin Reorientation Transition Temperature.
    Chemphyschem 2018 Jun 7. Epub 2018 Jun 7.
    School of Materials Science and Engineering, Nanyang Technological University, Singapore, 639798, Singapore.
    Nd-Fe-B magnets, possessing the highest energy product, are extensively used in cutting-edge applications, including electrical machines and electrical vehicles. An environmentally benign and cost effective synthesis method of Cr alloyed Nd (Fe,Co) B magnetic nanoparticles using a dry mechanochemical process is reported. The method is solvent free, facile, energy efficient and scalable. Read More

    Design of Perchlorotriphenylmethyl (PTM) Radical-Based Compounds for Opto-Electronic Applications: The Role of Orbital Delocalization.
    Chemphyschem 2018 Jun 7. Epub 2018 Jun 7.
    Perchlorotriphenylmethyl (PTM) radical-based compounds are widely exploited as molecular switching units. However, their application in opto-electronics is limited by the fact that they exhibit intense absorption bands only in a narrow range of the UV region around 385 nm. Recent experimental works have reported new PTM based compounds which present a broad absorption in the visible region although the origin of this behaviour is not fully explained. Read More

    Non-steric interactions predict the trend and steric interactions the offset of protein stability in cells.
    Chemphyschem 2018 Jun 6. Epub 2018 Jun 6.
    University of Illinois, Chemistry, 600 South Mathews Ave., Box 5-6, 61801, Urbana, UNITED STATES.
    Although biomolecules evolved to function in the cell, most biochemical assays are carried out in vitro. In-cell studies highlight how steric and non-steric interactions modulate protein folding and interactions. VlsE and PGK present two extremes of chemical behavior in the cell: the extracellular protein VlsE is destabilized in eukaryotic cells, whereas the cytoplasmic protein PGK is stabilized. Read More

    Internal Redox Polarity of an Individual G. sulfurreducens Bacterial Cell Attached to an Inorganic Substrate.
    Chemphyschem 2018 Jun 6. Epub 2018 Jun 6.
    Center for Bio/Molecular Science and Engineering, US Naval Research Laboratory, Washington, DC, 20375, USA.
    Bacterial cell polarity is an internal asymmetric distribution of subcellular components, including proteins, lipids, and other molecules that correlates with the cell ability to sense energy and metabolite sources, chemical signals, quorum signals, toxins, and movement in the desired directions. This ability also plays central role in cell attachment to various surfaces and biofilm formation. Mechanisms and factors controlling formation of this cell internal asymmetry are not completely understood. Read More

    Large Electro-Optic Kerr-Effect in Ionic Liquid Crystals: Connecting Features of Liquid Crystals and Polyelectrolytes.
    Chemphyschem 2018 Jun 6. Epub 2018 Jun 6.
    Universität Stuttgart, Institut für Physikalische Chemie, Pfaffenwaldring 55, 70569, Stuttgart, GERMANY.
    The electro-optic Kerr effect in the isotropic phase of two ionic liquid crystals (ILCs) is investigated and compared to the Kerr effect in non-ionic liquid crystals (LCs) with same phase sequences, namely direct isotropic to hexagonal columnar transitions and direct isotropic to smectic-A transitions. Up to electric field amplitudes of some 106 V m-1, the optical birefringence induced in the isotropic phases follows Kerr's law and strongly increases when the temperature approaches the transition temperature into the particular liquid crystalline phase. Close to the transition, maximum Kerr constants in the order of 10-11 m V-2 are found, which are more than ten times higher than the Kerr constant of nitrobenzene, a strongly dipolar fluid with a huge Kerr effect applied in optical shutters and phase modulators. Read More

    Mesoporous ZnFe₂O₄ photoanodes with template-tailored mesopores and temperature-dependent photocurrents.
    Chemphyschem 2018 Jun 6. Epub 2018 Jun 6.
    Justus-Liebig-University Giessen, Institute of Physical Chemistry, Heinrich-Buff-Ring17, 35392, Giessen, GERMANY.
    Mesoporous ZnFe2O4 photoanodes have been prepared via dip-coating utilizing the evaporation-induced self-assembly of two different block-copolymer templates to investigate the influence of pore geometry on the photoelectrochemcial performance of those earth-abundant photoelectrodes. The use of commercial block copolymers, triblock copolymer Pluronic® F127 and the diblock copolymer PIB3000 as templates, leads to different pore morphologies under identical preparation condition due to different polymer stabilities. Interestingly, pore morphology in mesoporous ZnFe2O4 turned out to be less important for the photoelectron-chemical performance. Read More

    Excited State Interaction of Ru(II) Imidazole Phenanthroline Complex [Ru(bpy)2ipH]2+ with 1,4-benzoquinone: Simple Electron Transfer or Proton Coupled Electron Transfer?
    Chemphyschem 2018 Jun 6. Epub 2018 Jun 6.
    Savitribai Phule Pune University, Department of Chemistry, Ganeshkhind Road, 411 007, Pune, INDIA.
    The unidirectional proton coupled electron transfer (PCET) from the excited state of Ru(II) imidazole phenanthroline complex [Ru(bpy)2ipH]2+ to 1,4-benzoquinone, was studied by steady-state (SS) and time-resolved (TR) fluorescence and transient absorption (TA) measurements. The pKa (9.7) and pKa* (8. Read More

    Behavior of a Metal Organic Framework Thin-Film at Elevated Temperature and Pressure as Studied with an Autoclave-Inserted Atomic Force Microscope.
    Chemphyschem 2018 Jun 6. Epub 2018 Jun 6.
    Utrecht University, Dept. of Inorganic Chemistry and Catalysis, Universiteitsweg 99, 3584 CG, Utrecht, NETHERLANDS.
    Bridging the gap in studying surface reactions, processes and morphology and measuring at relevant conditions is crucial for our understanding of the working principles of porous crystalline materials. Scanning Tunneling Microscopy is limited because of the required conductivity of the sample, while Atomic Force Microscopy (AFM) is often challenging due to the physical underlying mechanism of the technique. Here, we report a tailor-made autoclave-inserted AFM, able to measure at ~ 20 bar and ~ 110°C. Read More

    Kinetics, Assembling, and Conformation Control of L-Cysteine Adsorption on Pt Investigated by in Situ FTIR Spectroscopy and QCM-D.
    Chemphyschem 2018 Jun 5. Epub 2018 Jun 5.
    Depto. Química Fundamental, Instituto de Química, Universidade de São Paulo, Av. Prof. Lineu Prestes, 05508-080, São Paulo - SP, Brazil.
    A quartz crystal microbalance method with dissipation (QCM-D) and attenuated total reflection Fourier-transform infrared (ATR-FTIRS) spectroscopy were used to study the adsorption of L-cysteine (L-Cys) on Pt. Through QCM-D, it was possible to verify that the viscoelastic properties of the adsorbed species play an important role in the adsorption, rendering Sauerbrey's equation inapplicable. The modelling of QCM-D data exposed two different processes for the adsorption reaction. Read More

    Coupling Resonances of Surface Plasmon in Gold Nanorod/Copper Chalcogenide Core-Shell Nanostructures and Their Enhanced Photothermal Effect.
    Chemphyschem 2018 Jun 4. Epub 2018 Jun 4.
    Department School of Physics and Technology, Wuhan University, Wuhan, 430072, P. R. China.
    Dual plasmonic Au@Cu S core-shell nanorods (NRs) have been fabricated by using a hydrothermal method and plasmon-coupled effect between the Au core and Cu S shell in the near-infrared (NIR) region. The extinction spectrum of Au@Cu S NRs is dominated by the surface plasmon resonance (SPR) of the Cu S shell, the transverse surface plasmon resonance (TSPR), and the longitudinal surface plasmon resonance (LSPR) of the Au NRs. With the Cu S shell increasing (fixed Au NRs), the TSPR peak slightly redshifts and the LSPR and SPR peaks blueshift, owing to competition between the redshift of the refractive index effect and blueshift from the plasmon coupled effect. Read More

    Direct Prediction of EPR Spectra from Lipid Bilayers: Understanding Structure and Dynamics in Biological Membranes.
    Chemphyschem 2018 Jun 2. Epub 2018 Jun 2.
    School of Chemistry, University of East Anglia, Norwich, NR4 7TJ, UK.
    Of the many biophysical techniques now being brought to bear on studies of membranes, electron paramagnetic resonance (EPR) of nitroxide spin probes was the first to provide information about both mobility and ordering in lipid membranes. Here, we report the first prediction of variable temperature EPR spectra of model lipid bilayers in the presence and absence of cholesterol from the results of large scale fully atomistic molecular dynamics (MD) simulations. Three types of structurally different spin probes were employed in order to study different parts of the bilayer. Read More

    Photoluminescent Carbon Dots: A Mixture of Heterogeneous Fractions.
    Chemphyschem 2018 Jun 1. Epub 2018 Jun 1.
    University of Miami, Department of Chemistry, 1301 Memorial Drive, 33124, Coral Gables, UNITED STATES.
    Photoluminescent carbon dots (CDs) fractions have been isolated from a gel-like material (GM), which was synthesized via a convenient one-step solvothermal route. In terms of purification, size exclusion chromatography (SEC) and dialysis were compared with acetone wash, which revealed the advantage of acetone wash. The pre-purified GM with acetone wash (A-GM) was further isolated by the reversed-phase preparative thin layer chromatography (TLC) with acetonitrile/water mixture (7:3; va/vw) as the developing solvent. Read More

    Quantitative Assessment of Xenon Exchange Kinetics with Cucurbit[6]uril in Physiological Saline.
    Chemphyschem 2018 Jun 1. Epub 2018 Jun 1.
    Physikalisch-Technische Bundesanstalt (PTB), Abbestr. 2-12, 10587, Berlin, Germany.
    Cucurbit[6]uril and xenon form supramolecular complexes that are of great potential for biosensing by NMR. This host-guest system acts alike a signaler in sensors facilitating the ultrasensitive detection of biomarkers by saturation transfer of chemically exchanging, hyperpolarized Xe. Here, the exchange process is evaluated by NMR exchange spectroscopy utilizing the preparation of anti-parallel longitudinal magnetization with respect to free and host-bound xenon and the variation of xenon concentration. Read More

    TCNQ Physisorption on the Topological Insulator Bi Se.
    Chemphyschem 2018 May 30. Epub 2018 May 30.
    Department of Chemistry, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, UK.
    Topological insulators are promising candidates for spintronic applications due to their topologically protected, spin-momentum locked and gapless surface states. The breaking of the time-reversal symmetry after the introduction of magnetic impurities, such as 3d transition metal atoms embedded in two-dimensional molecular networks, could lead to several phenomena interesting for device fabrication. The first step towards the fabrication of metal-organic coordination networks on the surface of a topological insulator is to investigate the adsorption of the pure molecular layer, which is the aim of this study. Read More

    The Influence of Modularity, Seeding, and Product Inhibition on Peptide Autocatalytic Network Dynamics.
    Chemphyschem 2018 May 29. Epub 2018 May 29.
    Ben-Gurion University of the Negev, Be'er Sheva, Israel.
    Chemical networks often exhibit emergent, systems-level properties that cannot be simply derived from the linear sum of the individual components. The design and analysis of increasingly complex chemical networks thus constitute a major area of research in Systems Chemistry. In particular, much research is focused on the emergence of functional properties in prebiotic chemical networks relevant to the origin and early evolution of life. Read More

    Pure Organic Persistent Room-Temperature Phosphorescence at both Crystalline and Amorphous States.
    Chemphyschem 2018 May 26. Epub 2018 May 26.
    Shanghai Key Lab of Electrical Insulation and Thermal Aging, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China.
    Persistent room-temperature phosphorescence (p-RTP) of pure organic materials is attracting increasing attention. The design of efficient phosphors and understanding the origin of p-RTP, however, remain challenging. Herein, to gain further insights into pure organic p-RTP, we prepared a group of carbazole (CZ) and methyl benzoate (MBA) conjugates with a methyl ester unit at the para (4-MBACZ), meta (3-MBACZ), and ortho (2-MBACZ) sites. Read More

    Why Is Benzene Unique? Screening Magnetic Properties of C H Isomers.
    Chemphyschem 2018 May 25. Epub 2018 May 25.
    CEITEC - Central European Institute of Technology, Masaryk University, Kamenice 5, CZ -, 62500, Brno, Czech Republic.
    Magnetic properties are commonly used to identify new aromatic molecules because it is generally believed that magnetization and energetic stability are correlated. To verify the potential correlation between the energy and magnetic response properties, we examined a set of 198 isomers of C H . The energy and magnetic properties of these molecules can be directly compared with no need to invoke any arbitrary reference state because the studied systems are all isomers. Read More

    Experimental Evidence for Azeotrope Formation from Protic Ionic Liquids.
    Chemphyschem 2018 May 25. Epub 2018 May 25.
    Department of Chemistry and Biochemistry, Faculty of Science of University of Porto, Rua do Campo Alegre, 4169-007, Porto, Portugal.
    Herein, we present experimental evidence that protic ionic liquids (PILs), derived from 1 : 1 liquid mixtures of the organic superbases 1,5-diazabicyclo[4.3.0]non-5-ene (DBN) and 1,8-diazabicyclo[5. Read More

    A Simple Strategy to Construct Amorphous Metal-Free Room Temperature Phosphorescent and Multi-Color Materials.
    Chemphyschem 2018 May 24. Epub 2018 May 24.
    Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing, 100875, China.
    It is urgent to develop a universal strategy for producing small organic molecules exhibiting efficient room temperature phosphorescence (RTP). An important contribution made by Ma and Tian et al. provides a general and applicable strategy to obtain amorphous organic molecules with efficient RTP emission by simply modifying phosphors onto β-cyclodextrin (β-CD). Read More

    Adsorption of Hydrogen Sulfide, Hydrosulfide and Sulfide at Cu(110) - Polarizability and Cooperativity Effects. First Stages of Formation of a Sulfide Layer.
    Chemphyschem 2018 May 24. Epub 2018 May 24.
    Department of Materials Science and Engineering, KTH Royal Institute of Technology, SE-, 100 44, Stockholm, Sweden.
    Understanding the surface site preference for single adsorbates, the interactions between adsorbates, how these interactions affect surface site specificity in adsorption and perturb the electronic states of surfaces is important for rationalizing the structure of interfaces and the growth of surface products. Herein, using density functional theory (DFT) calculations, we investigated the adsorption of H S, HS and, S onto Cu(110). The surface site specificity observed for single adsorbates can be largely affected by the presence of other adsorbates, especially S that can affect the adsorption of other species even at distances of 13 Å. Read More

    Efficient Fabrication of Stable Graphene-Molecule-Graphene Single-Molecule Junctions at Room Temperature.
    Chemphyschem 2018 May 23. Epub 2018 May 23.
    Centre for Nanoscale Science and Technology, Key Laboratory for the Physics and Chemistry of Nanodevices, Department of Electronics, Peking University, Beijing, 100871, China.
    We present a robust approach to fabricate stable single-molecule junctions at room temperature using single-layer graphene as nanoelectrodes. Molecular scale nano-gaps in graphene were generated using an optimized fast-speed feedback-controlled electroburning process. This process shortened the time for creating a single nano-gap to be less than one minute while keeping a yield higher than 97 %. Read More

    Potential Use of Squarates and Croconates as Singlet Fission Sensitizers.
    Chemphyschem 2018 May 23. Epub 2018 May 23.
    POLYMAT, University of the Basque Country UPV/EHU, Joxe Mari Korta Center, Avda. Tolosa 72, 20018, Donostia - San Sebastián, Spain.
    The geometrical and electronic structures of 44 squarate and croconate derivatives are computationally studied by quantum chemistry methods, in the pursuit of new singlet fission sensitizers. A non-negligible singlet open-shell diradical character is observed for most of the studied molecules, which can be controlled through chemical substitution as well as by the size of the central ring. Such a diradical character is related to small singlet-triplet energy gaps, facilitating the accomplishment of the singlet fission energetic requirements. Read More

    Thermally Activated Self-metalation of Carboxy-functionalized Porphyrin Films on MgO Nanocubes.
    Chemphyschem 2018 May 23. Epub 2018 May 23.
    Lehrstuhl für Physikalische Chemie II, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstraße 3, D-, 91058, Erlangen, Germany.
    We investigated the adsorption of different free-base carboxyl-functionalized porphyrins, 5,10,15,20-tetrakis(4-carboxyphenyl)-21,23H-porphyrin (2H-TCPP) and 5(4-carboxyphenyl)-10,15,20-triphenyl-21,23H-porphyrin (2H-MCTPP), on MgO nanocubes combining IR, UV/Vis and photoluminescence emission spectroscopy. The thermal behavior of the films was monitored in-situ during annealing. Both porphyrins bind to the nanocubes via one and two acid groups respectively, yielding monolayer films consisting of tilted molecules. Read More

    Functionalization of Carbon Spheres with a Porphyrin-Ferrocene Dyad.
    Chemphyschem 2018 May 21. Epub 2018 May 21.
    Dipartimento di Ingegneria Industriale, Università degli Studi di Roma "Tor Vergata", Via del Politecnico 1, 00133-, Rome, Italy.
    Meso-tetraphenylporphyrin connected with a ferrocene molecule in the beta-position of the macrocycle through a triple carbon-carbon bond has been bound to carbon spheres using the Prato-Maggini reaction. The ethynyl or/and phenylene ethynylene subunits were chosen as a linking bridge to give a high conjugation degree between the donor (i. e. Read More

    Hyperpolarized Porous Silicon Nanoparticles: Potential Theragnostic Material for Si Magnetic Resonance Imaging.
    Chemphyschem 2018 May 20. Epub 2018 May 20.
    Department of Bionano Technology, Hanyang University, Ansan, 15588, South Korea.
    Porous silicon nanoparticles have recently garnered attention as potentially-promising biomedical platforms for drug delivery and medical diagnostics. Here, we demonstrate porous silicon nanoparticles as contrast agents for Si magnetic resonance imaging. Size-controlled porous silicon nanoparticles were synthesized by magnesiothermic reduction of silica nanoparticles and were surface activated for further functionalization. Read More

    The Vibrational Circular Dichroism Pattern of the ν(C=O) Bands in Isoindolinones.
    Chemphyschem 2018 May 18. Epub 2018 May 18.
    Institute of Nuclear Chemistry and Technology, 16 Dorodna Street, 03-195, Warsaw, Poland.
    The IR and vibrational circular dichroism (VCD) spectra of both enantiomers of Me-, iPr-, nBu-, Ph-, and CH Ph-substituted isoindolinones in solution and KBr pellets were measured and interpreted by DFT calculations. The spectra in solution revealed no important differences in the C=O stretching vibration region while the interpretation of very distinct spectra taken in pellets required determining the crystal structures. The studied compounds crystallized in the P2 2 2 (Me, iPr, CH Ph), P3 (nBu), and P2 (Ph) space groups. Read More

    Formation of Supramolecular Clusters at the Interface of Zeolite X Following the Adsorption of Rare-Earth Cations and Their Impact on the Macroscopic Properties of the Zeolite.
    Chemphyschem 2018 May 18. Epub 2018 May 18.
    University of Ferrara, Department of Chemistry and Pharmaceutical Sciences, Via L. Borsari, 46, 44121, Ferrara, Italy.
    The adsorption behavior of neodymium (Nd ) and yttrium (Y ) cations on synthetic FAU zeolite X in its sodium form (NaX) has been investigated by means of macroscopic (adsorption isotherm determination and thermal analysis) and microscopic measurements (including solid-state NMR spectroscopy and X-ray powder diffraction). The multidisciplinary study reveals some unexpected features. Firstly, adsorption constants of cations are not correlated to their ionic radii or hydration enthalpy. Read More

    Paramagnetic Metal-Ion Dopants as Polarization Agents for Dynamic Nuclear Polarization NMR Spectroscopy in Inorganic Solids.
    Chemphyschem 2018 May 17. Epub 2018 May 17.
    Department of Materials and Interfaces, Weizmann Institute of Science, Rehovot, 761000, Israel.
    Dynamic nuclear polarization (DNP), a technique in which the high electron spin polarization is transferred to surrounding nuclei via microwave irradiation, equips solid-state NMR spectroscopy with unprecedented sensitivity. The most commonly used polarization agents for DNP are nitroxide radicals. However, their applicability to inorganic materials is mostly limited to surface detection. Read More

    Efficient Adsorption Characteristics of Pristine and Silver-Doped Graphene Oxide Towards Contaminants: A Potential Membrane Material for Water Purification?
    Chemphyschem 2018 May 16. Epub 2018 May 16.
    Centre for Theoretical and Computational Molecular Science, Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, Qld 4072, Australia.
    In this work, we have investigated the potential of pristine and silver (Ag)-functionalized graphene oxide monolayers GO (GO-Ag) as efficient membranes for water filtration. Our first principles calculations based on density functional theory (DFT) reveal the hydrophilic nature of GO surfaces. The phonon frequency calculations within density functional perturbation theory (DFPT) confirmed the stability of GO sheets in aqueous media. Read More

    IR, Raman, and Vibrational Optical Activity Spectra of Methyl Glycidate in Chloroform and Water: The Clusters-in-a-liquid Solvation Model.
    Chemphyschem 2018 May 16. Epub 2018 May 16.
    Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada, T6G 2G2.
    Solvent effects, in particular those involving water as the solvent, are of significant interest to the chemistry and physics communities. IR, vibrational circular dichroism (VCD), Raman, and Raman optical activity (ROA) spectra of methyl glycidate in two very different solvents, namely CCl and water, have been measured experimentally and simulated theoretically. The observed spectra in CCl could be well modelled using the polarizable continuum model for the solvent, whereas the situation is much different in water. Read More

    Separating Extreme pH Gradients Using Amphiphilic Copolymer Membranes.
    Chemphyschem 2018 May 15. Epub 2018 May 15.
    Department of Chemistry, University College London, 20 Gordon street, WC1H 0AJ, London, UK.
    Polymeric vesicles, also called polymersomes, are highly efficient biomimetic systems. They can generate compartmentalized volumes at the nanoscale supported by synthetic amphiphilic membranes that closely mimic their biological counterparts. Membrane permeability and the ability to separate extreme pH gradients is a crucial condition a successful biomimetic system must meet. Read More

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