Articles in 2014

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  • The maximum attainable capacity of the Li–O2 battery is limited by the passivation of its cathode by electronically insulating Li2O2. It is now shown that electrolyte additives, which activate solution-mediated growth of Li2O2, make it possible to circumvent this fundamental limitation, leading to design rules for additive selection.

    • Nagaphani B. Aetukuri
    • Bryan D. McCloskey
    • Alan C. Luntz
    Article
  • Amines are essential in a number of research areas, but a general, selective and step-efficient synthesis has been elusive. Now, the use of a single copper catalyst to transform alkynes into enamines, α-chiral branched alkylamines, and linear alkylamines is described. These transformations have been applied in the preparation of a selection of current pharmaceutical agents.

    • Shi-Liang Shi
    • Stephen L. Buchwald
    Article
  • The mammalian oocyte cell cycle is regulated by massive zinc fluxes which culminate in coordinated ejections of ~1010 zinc ions at fertilization. Four single-cell physiochemical approaches (live-cell fluorescence imaging, scanning transmission electron microscopy with energy dispersive spectroscopy, X-ray fluorescence microscopy and tomography) reveal that these ‘zinc sparks’ originate from thousands of cortical vesicles which each release ~106 zinc ions.

    • Emily L. Que
    • Reiner Bleher
    • Thomas V. O'Halloran
    Article
  • Peptides that self-assemble into nanostructures are of interest for many applications, including ones relevant to cosmetics, food, biomedicine and nanotechnology. Now, computational tools have been developed that enable peptide sequence space to be rapidly searched for supramolecular properties and this approach has been used to identify unprotected tripeptide hydrogelators.

    • Pim W. J. M. Frederix
    • Gary G. Scott
    • Tell Tuttle
    Article
  • Crystals of hexachlorobenzene easily break when pressed on the (100) face, but bend to 360° without disintegrating when stress is applied on the (001) face. In the latter case this extraordinary malleability arises from the segregation and sliding of layers of molecules in the crystal, a process in which halogen–halogen interactions are broken and reformed.

    • Manas K. Panda
    • Soumyajit Ghosh
    • Panče Naumov
    Article
  • A method for rapidly screening small-molecule inhibitors of amyloid assembly has been developed. This method uses electrospray ionization–ion mobility spectrometry–mass spectrometry to detect and identify the type of inhibition. A screen of this nature could help in the discovery of therapeutics for numerous diseases associated with aberrant protein aggregation.

    • Lydia M. Young
    • Janet C. Saunders
    • Alison E. Ashcroft
    Article
  • Gas sorption and separation in porous materials is dependent on the host–guest binding within any given system. Now, the molecular details of cooperative binding between small hydrocarbons and a metal–organic framework, NOTT-300, at multiple sites have been elucidated by complementary scattering and diffraction techniques. This material is also capable of separating C1 and C2 hydrocarbons under ambient conditions.

    • Sihai Yang
    • Anibal J. Ramirez-Cuesta
    • Martin Schröder
    Article
  • The stereochemical outcome of enzyme-catalysed reactions with physiological substrates is typically governed by the well-defined geometry of the enzyme active site. Now, a rare example is reported where the substrate controls the stereoselectivity of a Michael-type addition during lanthipeptide biosynthesis.

    • Weixin Tang
    • Gonzalo Jiménez-Osés
    • Wilfred A. van der Donk
    Article
  • The pseudopterosins are a family of natural products whose interesting anti-inflammatory and pain-relieving properties have inspired many synthetic approaches. Now, an unusual approach that starts with an axially chiral hydrocarbon that engages in a triple Diels–Alder sequence has been shown to result in the shortest total synthesis of a pseudopterosin so far.

    • Christopher G. Newton
    • Samuel L. Drew
    • Michael S. Sherburn
    Article
  • The ability to achieve strong molecular recognition in water is a key challenge for supramolecular chemistry. Now, halogen bonding — the attractive interaction between an electron-deficient halogen atom and a Lewis base — has been shown to be superior to hydrogen bonding for strong anion binding in water. Ripple image: © PhotoDisc/Getty Images.

    • Matthew J. Langton
    • Sean W. Robinson
    • Paul D. Beer
    Article
  • The use of β-lactam antibiotics is severely threatened by metallo-β-lactamases (MBLs), which contribute to the development of resistance. Now, crystallographic and solution studies reveal that recently reported MBL inhibition with a rhodanine can be attributed to fragmentation and complex formation with the resulting thioenolate.

    • Jürgen Brem
    • Sander S. van Berkel
    • Christopher J. Schofield
    Article
  • Modifying or functionalizing transition metal dichalcogenides (TMDs) allows their properties to be altered and controlled. Now, non-defect-mediated covalent functionalization of single-layer semiconducting TMDs such as MoS2, WS2 and MoSe2 has been demonstrated by reacting them with organohalides, utilizing the excess charge in the 1T metallic phase.

    • Damien Voiry
    • Anandarup Goswami
    • Manish Chhowalla
    Article
  • The mechanism of O2 reduction in aprotic solvents is important for the operation of Li–O2 batteries but is not well understood. A single unified mechanism is now described that regards previous models as limiting cases. It shows that the solubility of the intermediate LiO2 is a critical factor that dictates the mechanism, emphasizing the importance of the solvent.

    • Lee Johnson
    • Chunmei Li
    • Peter G. Bruce
    Article
  • Kinetic, X-ray crystallographic and computational studies have enabled the formulation of a comprehensive mechanistic picture of the enantioselective sulfenofunctionalization reaction of alkenes and a stereochemical model for the origin of the enantioselectivity. The experiments resulted in the development of 2,6-dialkylaryl sulfenylating agents, improving the enantioselectivity of the reaction to >99:1 for γ-alkenols.

    • Scott E. Denmark
    • Eduard Hartmann
    • Hao Wang
    Article
  • Natural products provide a rich source of leads for drug discovery. Now, a computational method is available that can be used to identify the macromolecular targets of these compounds. Much like medicinal chemists' reasoning, the software infers target information by comparing the substructures with those of drugs and other natural products with known targets.

    • Daniel Reker
    • Anna M. Perna
    • Gisbert Schneider
    Article
  • Computational chemistry is traditionally used to interpret experimental findings. Now its use in reaction discovery is described with the development of the ab initio nanoreactor — a highly accelerated, first-principles molecular dynamics simulation of chemical reactions that discovers new molecules and mechanisms without preordained reaction coordinates or elementary steps.

    • Lee-Ping Wang
    • Alexey Titov
    • Todd J. Martínez
    Article
  • Transferring molecular motion to macroscopic shape change of a crystal has potential application in actuators, or ‘artificial muscles’. Now, a single crystal of a Ni complex has been shown to exhibit a large, abrupt, temperature-induced crystal expansion/contraction near room temperature. The crystal deformation is induced by a collective 90° rotation of oxalate anions in the complex.

    • Zi-Shuo Yao
    • Masaki Mito
    • Osamu Sato
    Article
  • The adenine analogue 2-aminopurine has been considered as intrinsically fluorescent and is widely used in biochemical assays to probe DNA and RNA structure. It is now shown that the molecule alone is nearly non-fluorescent, however, its fluorescence is increased by up to 95 times through hydrogen bonding to a single water molecule.

    • Simon Lobsiger
    • Susan Blaser
    • Samuel Leutwyler
    Article
  • The programmed assembly of single DNA strands into bricks and ultimately micrometre-sized two-dimensional crystals with prescribed depths up to 80 nm is described. These crystals display intricate three-dimensional features including continuous or discontinuous cavities and channels with nanometre precision, and can pack DNA helices in parallel or perpendicularly to the plane of the crystals.

    • Yonggang Ke
    • Luvena L. Ong
    • Peng Yin
    Article