3,536 results match your criteria Accounts of Chemical Research [Journal]


Synergetic Transformation of Solid Inorganic-Organic Hybrids into Advanced Nanomaterials for Catalytic Water Splitting.

Acc Chem Res 2018 Jun 22. Epub 2018 Jun 22.

Department of Chemistry, School of Science, and Tianjin Key Laboratory of Molecular Optoelectronic Science, Tianjin University, and Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072 , P. R. China.

The rational synthesis of advanced nanomaterials with well-defined structures has been intensively studied due to the remarkable properties and intriguing applications of the formed materials. Recently, inorganic-organic hybrids have been widely adopted as precursors for chemical transformations toward the preparation of diverse nanomaterials. Specifically, inorganic and organic species with nano/molecule/atom-scale distribution serve as self-templates and sacrificial agents, respectively, endowing the products with controlled morphologies, band gaps, defects, and spatial architectures. Read More

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The Xanthate Route to Ketones: When the Radical Is Better than the Enolate.

Authors:
Samir Z Zard

Acc Chem Res 2018 Jun 22. Epub 2018 Jun 22.

Laboratoire de Synthèse Organique , CNRS UMR 7652 Ecole Polytechnique , 91128 Palaiseau Cedex , France.

The alkylation of enolates is one of the backbones of ketone chemistry, yet in practice it suffers from numerous limitations due to problems of regiochemistry (including O- versus C-alkylation), multiple alkylations, self-condensation, competing elimination, and incompatibility with many polar groups that have to be protected. Over the years, various solutions have been devised to overcome these difficulties, such as the employment of auxiliary ester or sulfone groups to modify the p K of the enolizable hydrogens, the passage by the corresponding hydrazones, the use of transition-metal-catalyzed redox systems to formally alkylate ketones with alcohols, etc. Most of these hurdles disappear upon switching to α-ketonyl radicals. Read More

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Collagen Structure-Function Relationships from Solid-State NMR Spectroscopy.

Acc Chem Res 2018 Jun 22. Epub 2018 Jun 22.

Department of Chemistry , University of Cambridge , Lensfield Road , Cambridge CB2 1EW , U.K.

The extracellular matrix of a tissue is as important to life as the cells within it. Its detailed molecular structure defines the environment of a tissue's cells and thus their properties, including differentiation and metabolic status. Collagen proteins are the major component of extracellular matrices. Read More

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Carbolong Chemistry: A Story of Carbon Chain Ligands and Transition Metals.

Acc Chem Res 2018 Jun 21. Epub 2018 Jun 21.

State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), and College of Chemistry and Chemical Engineering , Xiamen University , Xiamen 361005 , China.

The construction of metal-carbon bonds is one of the most important issues of organometallic chemistry. However, the chelation of polydentate ligands to a metal via several metal-carbon bonds is rare. Metallapentalyne, which can be viewed as a 7-carbon (7C) chain coordinated to a metal via three metal-carbon bonds, was first reported in 2013. Read More

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Laser-Induced Graphene.

Acc Chem Res 2018 Jun 20. Epub 2018 Jun 20.

Research on graphene abounds, from fundamental science to device applications. In pursuit of complementary morphologies, formation of graphene foams is often preferred over the native two-dimensional (2D) forms due to the higher available area. Graphene foams have been successfully prepared by several routes including chemical vapor deposition (CVD) methods and by wet-chemical approaches. Read More

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Discovery and Evolution of Polyoxopalladates.

Acc Chem Res 2018 Jun 18. Epub 2018 Jun 18.

Department of Life Sciences and Chemistry , Jacobs University , Campus Ring 1 , 28759 Bremen , Germany.

Noble metal catalysts, in particular palladium-containing materials, are of prime commercial interest, because of their role as oxidation catalysts in automobile emission-control systems and reforming catalysts for the production of high-octane gasoline. However, despite almost two centuries of research, the precise structure of such materials is still ill-defined on the sub-nanometer scale, which severely limits the understanding of the underlying catalytic mechanisms. As a burgeoning class of structurally well-defined noble metal oxide nanoclusters, polyoxopalladates (POPs) have been highly rated as ideal models to fully decipher the molecular mechanism of noble metal-based catalysis. Read More

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June 2018
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Unraveling the Detailed Mechanism of Excited-State Proton Transfer.

Acc Chem Res 2018 Jun 15. Epub 2018 Jun 15.

State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics , Chinese Academy of Science , Dalian 116023 , Liaoning , China.

As one of the most fundamental processes, excited-state proton transfer (ESPT) plays a major role in both chemical and biological systems. In the past several decades, experimental and theoretical studies on ESPT systems have attracted considerable attention because of their tremendous potential in fluorescent probes, biological imaging, white-light-emitting materials, and organic optoelectronic materials. ESPT is related to fluorescence properties and usually occurs on an ultrafast time scale at or below 100 fs. Read More

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Molecular Approach to Conjugated Polymers with Biomimetic Properties.

Acc Chem Res 2018 Jun 13. Epub 2018 Jun 13.

Polymer Electronics Research Centre, School of Chemical Sciences , University of Auckland , Auckland 1010 , New Zealand.

The field of bioelectronics involves the fascinating interplay between biology and human-made electronics. Applications such as tissue engineering, biosensing, drug delivery, and wearable electronics require biomimetic materials that can translate the physiological and chemical processes of biological systems, such as organs, tissues. and cells, into electrical signals and vice versa. Read More

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Informing Molecular Design by Stereoelectronic Theory: The Fluorine Gauche Effect in Catalysis.

Acc Chem Res 2018 Jun 12. Epub 2018 Jun 12.

Organisch-Chemisches Institut , Westfälische Wilhelms-Universität Münster , Corrensstrasse 40 , 48149 Münster , Germany.

The axioms of stereoelectronic theory constitute an atlas to navigate the contours of molecular space. All too rarely lauded, the advent and development of stereoelectronic theory has been one of organic chemistry's greatest triumphs. Inevitably, however, in the absence of a comprehensive treatise, many of the field's pioneers do not receive the veneration that they merit. Read More

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Mesoscale Battery Science: The Behavior of Electrode Particles Caught on a Multispectral X-ray Camera.

Acc Chem Res 2018 Jun 11. Epub 2018 Jun 11.

Stanford Synchrotron Radiation Lightsource , SLAC National Accelerator Laboratory , Menlo Park , California 94025 , United States.

Functional materials and devices are usually morphologically complex and chemically heterogeneous. Their structures are often designed to be hierarchical because of the desired functionalities, which usually require many different components to work together in a coherent manner. The lithium ion battery, as an energy storage device, is a very typical example of this kind of structure. Read More

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Stimuli-Responsive Supramolecular Assemblies Constructed from Pillar[ n]arenes.

Acc Chem Res 2018 Jun 11. Epub 2018 Jun 11.

Graduate School of Natural Science and Technology , Kanazawa University , Kakuma-machi , Kanazawa , Ishikawa 920-1192 , Japan.

Supramolecular assemblies are constructed from at least two molecules through various noncovalent bonding modes such as hydrogen bonding, cationic-anionic electrostatic interactions, aromatic interactions, metal-ligand bonding, hydrophobic-hydrophilic interactions, and charge-transfer interactions. Owing to the dynamic and reversible nature of these noncovalent bonds, the assembly and disassembly of these molecules are dynamic and reversible. Molecules self-assemble to form the most conformationally and thermally stable structures through these noncovalent interactions. Read More

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Superwetting Electrodes for Gas-Involving Electrocatalysis.

Acc Chem Res 2018 Jun 8. Epub 2018 Jun 8.

State Key Laboratory of Chemical Resource Engineering, Beijing Advanced Innovation Center for Soft Matter Science and Engineering , Beijing University of Chemical Technology , Beijing 100029 , P. R. China.

Gas-involving electrochemical reactions, including gas evolution reactions and gas consumption reactions, are essential components of the energy conversion processes and gathering elevating attention from researchers. Besides the development of highly active catalysts, gas management during gas-involving electrochemical reactions is equally critical for industrial applications to achieve high reaction rates (hundreds of milliamperes per square centimeter) under practical operation voltages. Biomimetic surfaces, which generally show regular micro/nanostructures, offer new insights to address this issue because of their special wetting capabilities. Read More

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Record Alkali Metal Intercalation by Highly Charged Corannulene.

Acc Chem Res 2018 Jun 6;51(6):1541-1549. Epub 2018 Jun 6.

Department of Chemistry , University at Albany, State University of New York , Albany , New York 12222 , United States.

The need for advanced energy storage technologies demands the development of new functional materials. Novel carbon-rich and carbon-based materials of different structural topologies attract significant attention in this regard. Attractive systems include a unique class of bowl-shaped polycyclic aromatic hydrocarbons that map onto fullerene surfaces and are thus often referred to as fullerene fragments, buckybowls, or π-bowls. Read More

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Conjugated Polymers in Bioelectronics.

Acc Chem Res 2018 Jun 6;51(6):1368-1376. Epub 2018 Jun 6.

Department of Chemistry and Centre for Plastic Electronics , Imperial College London , London SW7 2AZ , U.K.

The emerging field of organic bioelectronics bridges the electronic world of organic-semiconductor-based devices with the soft, predominantly ionic world of biology. This crosstalk can occur in both directions. For example, a biochemical reaction may change the doping state of an organic material, generating an electronic readout. Read More

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Ru(II) Polypyridyl Complexes Derived from Tetradentate Ancillary Ligands for Effective Photocaging.

Acc Chem Res 2018 Jun 5;51(6):1415-1421. Epub 2018 Jun 5.

Department of Chemistry , Wayne State University , Detroit , Michigan 48202 , United States.

Metal complexes have many proven applications in the caging and photochemical release of biologically active compounds. Photocaging groups derived from Ru(II) traditionally have been composed of ancillary ligands that are planar and bi- or tridentate, such as 2,2'-bipyridine (bpy), 2,2':6',2″-terpyridine (tpy), and 1,10-phenanthroline (phen). Complexes bearing ancillary ligands with denticities higher than three represent a new class of Ru(II)-based photocaging groups that are grossly underdeveloped. Read More

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June 2018
2 Reads

In-Cell NMR in Human Cells: Direct Protein Expression Allows Structural Studies of Protein Folding and Maturation.

Acc Chem Res 2018 Jun 5;51(6):1550-1557. Epub 2018 Jun 5.

Magnetic Resonance Center - CERM , University of Florence , 50019 Sesto Fiorentino, Italy.

Cellular structural biology methods are needed to characterize biological processes at atomic resolution in the physiological environment of the cell. Toward this goal, solution in-cell NMR is a powerful approach because it provides structural and dynamic data on macromolecules inside living cells. Several approaches have been developed for in-cell NMR in cultured human cells, which are needed to study processes related to human diseases that rely on the delivery of exogenous macromolecules to the cells. Read More

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June 2018
2 Reads

Promoting Intermolecular C-N Bond Formation under the Auspices of Iodine(III).

Authors:
Kilian Muñiz

Acc Chem Res 2018 Jun 4;51(6):1507-1519. Epub 2018 Jun 4.

Institute for Chemical Research of Catalonia (ICIQ) , The Barcelona Institute of Science & Technology , Av. Països Catalans 16 , 43007 Tarragona , Spain.

The quest for the development of new protocols that provide general conditions for oxidative carbon-nitrogen bond formation has grown over recent years. Within this context, due to feasibility and benignity considerations in biochemical sciences, reactions that rely on main group oxidants as the only promoters have received particular interest. We have recently found that simple protonolysis events enable the incorporation of nitrogenated groups of the bissulfonimide family into the coordination sphere of common iodine(III) complexes such as diacetoxy iodobenzene. Read More

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Isoelectronic Manganese and Iron Hydrogenation/Dehydrogenation Catalysts: Similarities and Divergences.

Acc Chem Res 2018 Jun 4;51(6):1558-1569. Epub 2018 Jun 4.

Institute of Applied Synthetic Chemistry , Technical University Vienna , Getreidemarkt 9 , A-1060 Vienna , Austria.

Sustainable processes that utilize nontoxic, readily available, and inexpensive starting materials for organic synthesis constitute a major objective in modern chemical research. In this context, it is highly important to perform reactions under catalytic conditions and to replace precious metal catalysts by earth-abundant nonprecious metal catalysts. In particular, iron and manganese are promising candidates, as these are among the most abundant metals in the earth's crust, are inexpensive, and exhibit a low environmental impact. Read More

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Quantum Transport through a Single Conjugated Rigid Molecule, a Mechanical Break Junction Study.

Acc Chem Res 2018 Jun 4;51(6):1359-1367. Epub 2018 Jun 4.

Kavli Institute of Nanoscience , Delft University of Technology , Delft 2600 GA , The Netherlands.

This Account provides an overview of our recent efforts to unravel charge transport characteristics of a metal-molecule-metal junction containing an individual π-conjugated molecule. The model system of our choice is an oligo(phenylene-ethynylene) consisting of three rings, in short OPE3, which represents a paradigmatic model system for molecular-scale electronics. Members of the OPE family are among the most studied in the field thanks to their simple and rigid structure, the possibility of chemically functionalizing them, and their clear transport characteristics. Read More

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High-Pressure Synthesis: A New Frontier in the Search for Next-Generation Intermetallic Compounds.

Acc Chem Res 2018 Jun 29;51(6):1315-1323. Epub 2018 May 29.

Department of Chemistry , Northwestern University , Evanston , Illinois 60208 , United States.

The application of high pressure adds an additional dimension to chemical phase space, opening up an unexplored expanse bearing tremendous potential for discovery. Our continuing mission is to explore this new frontier, to seek out new intermetallic compounds and new solid-state bonding. Simple binary elemental systems, in particular those composed of pairs of elements that do not form compounds under ambient pressures, can yield novel crystalline phases under compression. Read More

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Development of Synthetic Methodologies via Catalytic Enantioselective Synthesis of 3,3-Disubstituted Oxindoles.

Acc Chem Res 2018 Jun 29;51(6):1443-1454. Epub 2018 May 29.

State Key Laboratory of Organometallic Chemistry , Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences , Shanghai 200032 , P. R. China.

3,3-Disubstituted oxindoles are widely distributed in natural products, drugs, and pharmaceutically active compounds. The absolute configuration and the substituents on the fully substituted C3 stereocenter of the oxindole often significantly influence the biological activity. Therefore, tremendous efforts have made to develop catalytic enantioselective syntheses of this prominent structural motif. Read More

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Optothermal Manipulations of Colloidal Particles and Living Cells.

Acc Chem Res 2018 Jun 25;51(6):1465-1474. Epub 2018 May 25.

Department of Mechanical Engineering and Texas Materials Institute , The University of Texas at Austin , Austin , Texas 78712 , United States.

Optical manipulation techniques are important in many fields. For instance, they enable bottom-up assembly of nanomaterials and high-resolution and in situ analysis of biological cells and molecules, providing opportunities for discovery of new materials, medical diagnostics, and nanomedicines. Traditional optical tweezers have their applications limited due to the use of rigorous optics and high optical power. Read More

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Multicomponent Reactions in Ligation and Bioconjugation Chemistry.

Acc Chem Res 2018 Jun 25;51(6):1475-1486. Epub 2018 May 25.

Center for Natural Products Research, Faculty of Chemistry , University of Havana , Zapata y G , Havana 10400 , Cuba.

Multicomponent reactions (MCRs) encompass an exciting class of chemical transformations that have proven success in almost all fields of synthetic organic chemistry. These convergent procedures incorporate three or more reactants into a final product in one pot, thus combining high levels of complexity and diversity generation with low synthetic cost. Striking applications of these processes are found in heterocycle, peptidomimetic, and natural product syntheses. Read More

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Arginine "Magic": Guanidinium Like-Charge Ion Pairing from Aqueous Salts to Cell Penetrating Peptides.

Acc Chem Res 2018 Jun 25;51(6):1455-1464. Epub 2018 May 25.

Institute of Organic Chemistry and Biochemistry , Czech Academy of Sciences , 166 10 Prague , Czech Republic.

It is a textbook knowledge that charges of the same polarity repel each other. For two monovalent ions in the gas phase at a close contact this repulsive interaction amounts to hundreds of kilojoules per mole. In aqueous solutions, however, this Coulomb repulsion is strongly attenuated by a factor equal to the dielectric constant of the medium. Read More

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June 2018
1 Read

Recent Advances on Sodium-Oxygen Batteries: A Chemical Perspective.

Acc Chem Res 2018 Jun 24;51(6):1532-1540. Epub 2018 May 24.

Department of Mechanical & Materials Engineering , University of Western Ontario , London , Ontario N6A 5B9 , Canada.

Releasing greenhouse gases into the atmosphere because of widespread use of fossil fuels by humankind has resulted in raising the earth's temperature during the past few decades. Known as global warming, increasing the earth's temperature may in turn endanger civilization on the earth by starting a cycle of environmental changes including climate change and sea level rise. Therefore, replacing fossil fuels with more sustainable energy resources has been considered as one of the main strategies to tackle the global warming crisis. Read More

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Biosynthesis of Lincosamide Antibiotics: Reactions Associated with Degradation and Detoxification Pathways Play a Constructive Role.

Acc Chem Res 2018 Jun 24;51(6):1496-1506. Epub 2018 May 24.

State Key Laboratory of Bioorganic and Natural Products Chemistry, Center for Excellence on Molecular Synthesis , Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences , 345 Lingling Road , Shanghai 200032 , China.

Natural products typically are small molecules produced by living organisms. These products possess a wide variety of biological activities and thus have historically played a critical role in medicinal chemistry and chemical biology either as chemotherapeutic agents or as useful tools. Natural products are not synthesized for use by human beings; rather, living organisms produce them in response to various biochemical processes and environmental concerns, both internal and external. Read More

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Control of Selectivity in Palladium(II)-Catalyzed Oxidative Transformations of Allenes.

Acc Chem Res 2018 Jun 24;51(6):1520-1531. Epub 2018 May 24.

Department of Organic Chemistry, Arrhenius Laboratory , Stockholm University , SE-106 91 Stockholm , Sweden.

Oxidation reactions play a central role in organic synthesis, and it is highly desirable that these reactions are mild and occur under catalytic conditions. In Nature, oxidation reactions occur under mild conditions via cascade processes, and furthermore, they often occur in an enantioselective manner with many of them involving molecular oxygen or hydrogen peroxide as the terminal oxidant. Inspired by the reactions in Nature, we have developed a number of Pd(II)-catalyzed cascade reactions under mild oxidative conditions. Read More

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Toward Total Synthesis of Thiolate-Protected Metal Nanoclusters.

Acc Chem Res 2018 Jun 24;51(6):1338-1348. Epub 2018 May 24.

Department of Chemical and Biomolecular Engineering , National University of Singapore , 4 Engineering Drive 4 , Singapore 117585.

Total synthesis, where desired organic- and/or biomolecules could be produced from simple precursors at atomic precision and with known step-by-step reactions, has prompted centuries-lasting bloom of organic chemistry since its conceptualization in 1828 (Wöhler synthesis of urea). Such expressive science is also highly desirable in nanoscience, since it represents a decisive step toward atom-by-atom customization of nanomaterials for basic and applied research. Although total synthesis chemistry is less established in nanoscience, recent years have witnessed seminal advances and increasing research efforts devoted into this field. Read More

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Modification of Side Chains of Conjugated Molecules and Polymers for Charge Mobility Enhancement and Sensing Functionality.

Acc Chem Res 2018 Jun 17;51(6):1422-1432. Epub 2018 May 17.

Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, CAS Center of Excellence in Molecular Science , Institute of Chemistry, Chinese Academy of Sciences , Beijing 100190 , P. R. China.

Organic semiconductors have received increasing attentions in recent years because of their promising applications in various optoelectronic devices. The key performance metric for organic semiconductors is charge carrier mobility, which is governed by the electronic structures of conjugated backbones and intermolecular/interchain π-π interactions and packing in both microscopic and macroscopic levels. For this reason, more efforts have been paid to the design and synthesis of conjugated frameworks for organic semiconductors with high charge mobilities. Read More

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The Chemical History of a Bubble.

Acc Chem Res 2018 May 17. Epub 2018 May 17.

Department of Chemistry , University of Illinois at Urbana-Champaign , 600 South Mathews Avenue , Urbana , Illinois 61801 United States.

Acoustic cavitation (the growth, oscillation, and rapid collapse of bubbles in a liquid) occurs in all liquids irradiated with sufficient intensity of sound or ultrasound. The collapse of such bubbles creates local heating and provides a unique source of energy for driving chemical reactions. In addition to sonochemical bond scission and formation, cavitation also induces light emission in many liquids. Read More

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Protons as Versatile Reporters in Solid-State NMR Spectroscopy.

Acc Chem Res 2018 Jun 15;51(6):1386-1395. Epub 2018 May 15.

Department Chemistry , Ludwig-Maximilians-University Munich , Butenandtstr. 5-13 , 81377 Munich , Germany.

Solid-state nuclear magnetic resonance (ssNMR) is a spectroscopic technique that is used for characterization of molecular properties in the solid phase at atomic resolution. In particular, using the approach of magic-angle spinning (MAS), ssNMR has seen widespread applications for topics ranging from material sciences to catalysis, metabolomics, and structural biology, where both isotropic and anisotropic parameters can be exploited for a detailed assessment of molecular properties. High-resolution detection of protons long represented the holy grail of the field. Read More

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Strategies toward Organic Carbon Monoxide Prodrugs.

Acc Chem Res 2018 Jun 15;51(6):1377-1385. Epub 2018 May 15.

Department of Chemistry and Center for Diagnostics and Therapeutics , Georgia State University , Atlanta , Georgia 30303 United States.

Carbon monoxide is widely acknowledged as an important gasotransmitter in the mammalian system with importance on par with that of nitric oxide. It has also been firmly established as a potential therapeutic agent with a wide range of indications including organ transplantation, cancer, bacterial infection, and inflammation-related conditions such as colitis and sepsis. One major issue in developing CO based therapeutics is its delivery in a pharmaceutically acceptable form. Read More

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Combining Ion Mobility and Cryogenic Spectroscopy for Structural and Analytical Studies of Biomolecular Ions.

Acc Chem Res 2018 Jun 10;51(6):1487-1495. Epub 2018 May 10.

Laboratoire de Chimie Physique Moléculaire , École Polytechnique Fédérale de Lausanne, EPFL SB ISIC LCPM , Station 6 , CH-1015 Lausanne , Switzerland.

Ion mobility spectrometry (IMS) has become a valuable tool in biophysical and bioanalytical chemistry because of its ability to separate and characterize the structure of gas-phase biomolecular ions on the basis of their collisional cross section (CCS). Its importance has grown with the realization that in many cases, biomolecular ions retain important structural characteristics when produced in the gas phase by electrospray ionization (ESI). While a CCS can help distinguish between structures of radically different types, one cannot expect a single number to differentiate similar conformations of a complex molecule. Read More

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Using Alkali Metal Ions To Template the Synthesis of Interlocked Molecules.

Acc Chem Res 2018 Jun 10;51(6):1324-1337. Epub 2018 May 10.

Department of Chemistry , National Taiwan University , No. 1, Sec. 4, Roosevelt Road , Taipei , Taiwan.

In 1987, Pedersen, Cram, and Lehn were awarded the Nobel Prize in Chemistry to honor their achievements in, among other things, the selective recognition of alkali metal ions by synthetic hosts. Almost three decades later, the 2016 Nobel Prize went to Stoddart, Sauvage, and Feringa for the development of artificial molecular machines, in which interlocked molecules play a significant role. Surprisingly, although many rotaxane- and catenane-based molecular machines have been constructed using various templating approaches, alkali metal ions, which are good templates for crown ether synthesis, have only rarely been applied as templates for the assembly of these interlocked molecules. Read More

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June 2018
1 Read

State-Resolved Metal Nanoparticle Dynamics Viewed through the Combined Lenses of Ultrafast and Magneto-optical Spectroscopies.

Acc Chem Res 2018 Jun 8;51(6):1433-1442. Epub 2018 May 8.

Department of Chemistry , The Pennsylvania State University , University Park , Pennsylvania 16802 , United States.

Electronic carrier dynamics play pivotal roles in the functional properties of nanomaterials. For colloidal metals, the mechanisms and influences of these dynamics are structure dependent. The coherent carrier dynamics of collective plasmon modes for nanoparticles (approximately 2 nm and larger) determine optical amplification factors that are important to applied spectroscopy techniques. Read More

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Solvent-Free Synthesis of Zeolites: Mechanism and Utility.

Acc Chem Res 2018 Jun 8;51(6):1396-1403. Epub 2018 May 8.

Department of Chemistry , Zhejiang University , Hangzhou 310028 , China.

Zeolites have been extensively studied for years in different areas of chemical industry, such as shape selective catalysis, ion-exchange, and gas adsorption and separation. Generally, zeolites are prepared from solvothermal synthesis in the presence of a large amounts of solvents such as water and alcohols in sealed autoclaves under autogenous pressure. Water has been regarded as essential to synthesize zeolites for fast mass transfer of reactants, but it occupies a large space in autoclaves, which greatly reduces the yield of zeolite products. Read More

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June 2018
1 Read

Aggregation-Induced Emission (AIE) Dots: Emerging Theranostic Nanolights.

Acc Chem Res 2018 Jun 7;51(6):1404-1414. Epub 2018 May 7.

Department of Chemical and Biomolecular Engineering , National University of Singapore , 4 Engineering Drive 4 , Singapore 117585 , Singapore.

Theranostic nanolights refer to luminescent nanoparticles possessing both imaging and therapeutic functions. Their shape, size, surface functions, and optical properties can be precisely manipulated through integrated efforts of chemistry, materials, and nanotechnology for customized applications. When localized photons are used to activate both imaging and therapeutic functions such as photodynamic or photothermal therapy, these theranostic nanolights increase treatment efficacy with minimized damage to surrounding healthy tissues, which represents a promising noninvasive nanomedicine as compared to conventional theranostic approaches. Read More

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June 2018
2 Reads

Nanosystems Based on Magnetic Nanoparticles and Thermo- or pH-Responsive Polymers: An Update and Future Perspectives.

Acc Chem Res 2018 May 7;51(5):999-1013. Epub 2018 May 7.

Italian Institute of Technology , via Morego 30 , 16163 Genoa , Italy.

Combining hard matter, like inorganic nanocrystals, and soft materials, like polymers, can generate multipurpose materials with a broader range of applications with respect to the individual building blocks. Given their unique properties at the nanoscale, magnetic nanoparticles (MNPs) have drawn a great deal of interest due to their potential use in the biomedical field, targeting several applications such as heat hubs in magnetic hyperthermia (MHT, a heat-damage based therapy), contrast agents in magnetic resonance imaging (MRI), and nanocarriers for targeted drug delivery. At the same time, polymers, with their versatile macromolecular structure, can serve as flexible platforms with regard to constructing advanced functional materials. Read More

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Ultrafast Coherent Control of Condensed Matter with Attosecond Precision.

Acc Chem Res 2018 May 7;51(5):1174-1184. Epub 2018 May 7.

Department of Photo-Molecular Science, Institute for Molecular Science , National Institutes of Natural Sciences , Okazaki 444-8585 Japan.

Coherent control is a technique to manipulate wave functions of matter with light. Coherent control of isolated atoms and molecules in the gas phase is well-understood and developed since the 1990s, whereas its application to condensed matter is more difficult because its coherence lifetime is shorter. We have recently applied this technique to condensed matter samples, one of which is solid para-hydrogen ( p-H). Read More

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May 2018
1 Read

Constructing New Bioorthogonal Reagents and Reactions.

Acc Chem Res 2018 May 4;51(5):1073-1081. Epub 2018 May 4.

Chemical tools are transforming our understanding of biomolecules and living systems. Included in this group are bioorthogonal reagents-functional groups that are inert to most biological species, but can be selectively ligated with complementary probes, even in live cells and whole organisms. Applications of these tools have revealed fundamental new insights into biomolecule structure and function-information often beyond the reach of genetic approaches. Read More

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Remote Asymmetric Induction Reactions using a E, E-Vinylketene Silyl N, O-Acetal and the Wide Range Stereocontrol Strategy for the Synthesis of Polypropionates.

Authors:
Seijiro Hosokawa

Acc Chem Res 2018 May 4;51(5):1301-1314. Epub 2018 May 4.

Department of Applied Chemistry, Faculty of Advanced Science and Engineering , Waseda University , 3-4-1 Ohkubo , Shinjuku-ku, Tokyo 169-8555 , Japan.

The construction of libraries of acyclic polyketides remains a challenging topic, mostly due to the difficulties associated with finding the right balance between diversity and brevity for the synthetic routes leading to polyketides. Recently, relatively short methods have been developed and applied to the synthesis of natural products. However, these short routes often suffer from limited diversity with respect to the arrangement of functional groups and stereochemistry, as these usually require reactions that direct multiple functional groups simultaneously in one step. Read More

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May 2018
2 Reads

Synthesis and Characterization of Metal-Encapsulating Si Cage Superatoms.

Acc Chem Res 2018 May 1. Epub 2018 May 1.

Department of Chemistry, Faculty of Science and Technology , Keio University , 3-14-1 Hiyoshi , Kohoku-ku, Yokohama 223-8522 , Japan.

Nanoclusters, aggregates of several to hundreds of atoms, have been one of the central issues of nanomaterials sciences owing to their unique structures and properties, which could be found neither in nanoparticles with several nanometer diameters nor in organometallic complexes. Along with the chemical nature of each element, properties of nanoclusters change dramatically with size parameters, making nanoclusters strong potential candidates for future tailor-made materials; these nanoclusters are expected to have attractive properties such as redox activity, catalysis, and magnetism. Alloying of nanoclusters additionally gives designer functionality by fine control of their electronic structures in addition to size parameters. Read More

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Machine Learning in Computer-Aided Synthesis Planning.

Acc Chem Res 2018 May 1;51(5):1281-1289. Epub 2018 May 1.

Department of Chemical Engineering , Massachusetts Institute of Technology , 77 Massachusetts Avenue , Cambridge , Massachusetts 02139 , United States.

Computer-aided synthesis planning (CASP) is focused on the goal of accelerating the process by which chemists decide how to synthesize small molecule compounds. The ideal CASP program would take a molecular structure as input and output a sorted list of detailed reaction schemes that each connect that target to purchasable starting materials via a series of chemically feasible reaction steps. Early work in this field relied on expert-crafted reaction rules and heuristics to describe possible retrosynthetic disconnections and selectivity rules but suffered from incompleteness, infeasible suggestions, and human bias. Read More

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Still Unconquered: Enantioselective Passerini and Ugi Multicomponent Reactions.

Acc Chem Res 2018 May 30;51(5):1290-1300. Epub 2018 Apr 30.

Laboratory of Synthesis and Natural Products, Institute of Chemical Sciences and Engineering , Ecole Polytechnique Fédérale de Lausanne, EPFL-SB-ISIC-LSPN, BCH5304 , CH-1015 Lausanne , Switzerland.

The Passerini three-component (P-3CR) and the Ugi four-component (U-4CR) are two of the most prominent isocyanide-based multicomponent reactions (IMCRs). The P-3CR transforms isocyanides, aldehydes (ketones), and carboxylic acids to α-acyloxy carboxamides, while the U-4CR converts isocyanides, aldehydes (ketones), amines, and carboxylic acids to α-acetamido carboxamides. Conversion of the high energy formal divalent isocyano carbon into a tetravalent amide carbonyl carbon provides the driving force for these reactions. Read More

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May 2018
1 Read

Indigoid Photoswitches: Visible Light Responsive Molecular Tools.

Acc Chem Res 2018 May 25;51(5):1153-1163. Epub 2018 Apr 25.

Ludwig-Maximilians-Universität München , Department für Chemie and Munich Center for Integrated Protein Science (CIPSM) , D-81377 Munich , Germany.

Indigoid photoswitches comprise a class of chromophores that are derived from the parent and well-known indigo dye. Different from most photoswitches their core structures absorb in the visible region of the spectrum in both isomeric states even without substitutions, which makes them especially interesting for applications not tolerant of high-energy UV light. Also different from most current photoswitching systems, they provide highly rigid structures that undergo large yet precisely controllable geometry changes upon photoisomerization. Read More

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Skin-Inspired Electronics: An Emerging Paradigm.

Acc Chem Res 2018 May 25;51(5):1033-1045. Epub 2018 Apr 25.

Department of Chemical Engineering , Stanford University , Stanford , California 94305 , United States.

Future electronics will take on more important roles in people's lives. They need to allow more intimate contact with human beings to enable advanced health monitoring, disease detection, medical therapies, and human-machine interfacing. However, current electronics are rigid, nondegradable and cannot self-repair, while the human body is soft, dynamic, stretchable, biodegradable, and self-healing. Read More

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Polar Imperfections in Amino Acid Crystals: Design, Structure, and Emerging Functionalities.

Acc Chem Res 2018 May 20;51(5):1238-1248. Epub 2018 Apr 20.

Department of Materials and Interfaces , Weizmann Institute of Science , Rehovot 76100 , Israel.

Crystals are physical arrays delineated by polar surfaces and often contain imperfections of a polar nature. Understanding the structure of such defects on the molecular level is of topical importance since they strongly affect the macroscopic properties of materials. Moreover, polar imperfections in crystals can be created intentionally and specifically designed by doping nonpolar crystals with "tailor-made" additives as dopants, since their incorporation generally takes place in a polar mode. Read More

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May 2018
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Alkyne Origami: Folding Oligoalkynes into Polyaromatics.

Acc Chem Res 2018 May 20;51(5):1206-1219. Epub 2018 Apr 20.

Department of Chemistry and Biochemistry , Florida State University , Tallahassee , Florida 32306 , United States.

Do not bend the triple bonds! This familiar undergraduate mantra must be disobeyed if the alkyne group is used as a building block in molecular construction. This Account will describe our exploits in "alkyne origami", that is, folding oligoalkynes into new shapes via cyclization cascades. This research stems from a set of guidelines for the cyclizations of alkynes that we suggested in 2011 ( Gilmore Chem. Read More

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May 2018
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Foldamer Tertiary Structure through Sequence-Guided Protein Backbone Alteration.

Acc Chem Res 2018 May 19;51(5):1220-1228. Epub 2018 Apr 19.

Department of Chemistry , University of Pittsburgh , Pittsburgh , Pennsylvania 15260 , United States.

The prospect of recreating the complex structural hierarchy of protein folding in synthetic oligomers with backbones that are artificial in covalent structure ("foldamers") has long fascinated chemists. Foldamers offer complex functions from biostable scaffolds and have found widespread applications in fields from biomedical to materials science. Most precedent has focused on isolated secondary structures or their assemblies. Read More

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May 2018
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