Volume 4 Issue 6, June 2012

Volume 4 Issue 6

A team of researchers from the University of Windsor in Canada have made a metal–organic framework (shown schematically on the cover) from [2]rotaxane linkers connected together with nodes comprising binuclear Cu(ii) clusters. Heating the material under vacuum at 150 °C removes water molecules from the structure and creates void spaces that enable the crown ether rings of the rotaxane building blocks to rotate unimpeded. This work demonstrates how the dynamics associated with interlocked molecules can be integrated into a robust and ordered framework.

Article p456.

COVER DESIGN: ALEX WING

Thesis

  • Thesis |

    Michelle Francl wonders what abstract objects might be lurking in our beakers.

    • Michelle Francl

Research Highlights

Blogroll

News and Views

  • News & Views |

    Proton conduction in both water and other hydrogen-bonded liquids occurs through successive proton transfers along the hydrogen-bond network. But first-principles simulations have revealed that the mechanism by which this occurs in orthophosphoric acid has some unusual features.

    • Rodolphe Vuilleumier
    •  & Daniel Borgis
  • News & Views |

    Flow chemistry has grown in stature as a technique with the potential to deliver synthetic complexity with assembly-line-like efficiency. Application of flow technology to the front-line antimalarial drug artemisinin promises to revolutionalize treatment.

    • Kevin Booker-Milburn
  • News & Views |

    Previous approaches to the development of self-repairing polymeric materials have required either the input of external energy or the use of a healing agent. Now, a new type of elastomer, in which hard/soft phase-separation occurs at the nanoscale, displays efficient and entirely autonomic self-repair through reversible hydrogen bonding.

    • Howard M. Colquhoun
  • News & Views |

    The behaviour of di-selenol enzyme mimics indicates that a halogen bond between selenium and iodine, and a chalcogen interaction between the two selenium atoms, play an important role in the activation of thyroid hormones.

    • Pierangelo Metrangolo
    •  & Giuseppe Resnati
  • News & Views |

    Supramolecular catalysts that combine an anionic chiral scaffold, a cationic coordinating structure and a metal centre have been shown to be highly effective for asymmetric synthesis. The success opens a new avenue for the design of new catalysts with a wide variety of chiral environments.

    • Hajime Ito
  • News & Views |

    Sensing neuronal activity using fluorescence has many potential advantages over current methods. Now, by taking advantage of photoinduced electron transfer, fluorescent sensors have been developed that allow high-fidelity recording of neural signals in real time.

    • A. Prasanna de Silva
  • News & Views |

    A dihydroboration–amination sequence provides a step-economical route to indolizidine alkaloids — a common structure in bioactive natural products.

    • Peter Shapland

Review

  • Review Article |

    Thiolate-protected gold surfaces and interfaces are archetypal systems in various fields of current research in nanoscience, materials science, inorganic chemistry and surface science. Examples include self-assembled monolayers of organic molecules on gold, passivated gold nanoclusters and molecule–gold junctions. This Review discusses recent experimental and theoretical breakthroughs that highlight common features of gold-sulfur bonding in these systems.

    • Hannu Häkkinen

Articles

  • Article |

    The dynamics of mechanically interlocked molecules such as catenanes and rotaxanes have been studied in solution as examples of rudimentary molecular switches and machines. A metal–organic framework with a [2]rotaxane as a building block demonstrates that such dynamic processes can also operate inside a solid-state material.

    • V. Nicholas Vukotic
    • , Kristopher J. Harris
    • , Kelong Zhu
    • , Robert W. Schurko
    •  & Stephen J. Loeb
  • Article |

    Proton transport in phosphate-based systems is important in biology and clean energy technologies, and phosphoric acid, being the best known intrinsic proton conductor, represents an important model. Ab initio molecular dynamics simulations now reveal that the interplay between extended, polarized, hydrogen-bonded chains and a frustrated hydrogen-bond network gives rise to the high conductivity in liquid phosphoric acid.

    • Linas Vilčiauskas
    • , Mark E. Tuckerman
    • , Gabriel Bester
    • , Stephen J. Paddison
    •  & Klaus-Dieter Kreuer
  • Article |

    Polymer materials that could spontaneously heal like tissues in living systems would significantly improve the safety, lifetime, energy efficiency and environmental impact of man-made materials. Now, a general multiphase design of autonomous self-healing elastomeric materials that do not require the input of external energy or healing agents is reported.

    • Yulin Chen
    • , Aaron M. Kushner
    • , Gregory A. Williams
    •  & Zhibin Guan
  • Article |

    Rather than create a chiral catalyst by combining a chiral ligand with a metal, here an achiral phosphine ligand endowed with a cationic ammonium group is ion-paired with a chiral binaphtholate. A palladium catalyst based on this strategy is shown to be effective for highly enantioselective allylic alkylation of α-nitrocarboxylates.

    • Kohsuke Ohmatsu
    • , Mitsunori Ito
    • , Tomoatsu Kunieda
    •  & Takashi Ooi
  • Article |

    Substituted aspartic acids are highly valuable as tools for biological research and as chiral building blocks for pharmaceuticals. Here, engineering of the enzyme methylaspartate ammonia lyase to accept a large variety of substituted amines and fumarates and catalyse the asymmetric synthesis of aspartic acid derivatives is described.

    • Hans Raj
    • , Wiktor Szymański
    • , Jandré de Villiers
    • , Henriëtte J. Rozeboom
    • , Vinod Puthan Veetil
    • , Carlos R. Reis
    • , Marianne de Villiers
    • , Frank J. Dekker
    • , Stefaan de Wildeman
    • , Wim J. Quax
    • , Andy-Mark W. H. Thunnissen
    • , Ben L. Feringa
    • , Dick B. Janssen
    •  & Gerrit J. Poelarends
  • Article |

    Triarylamine derivatives in solution have been self-assembled into organic nanowires between two electrodes, under white-light irradiation and in the presence of a voltage. The resulting fibres possess a very high electric conductivity as well as a metallic behaviour when cooled down to a temperature of 1.5 K.

    • Vina Faramarzi
    • , Frédéric Niess
    • , Emilie Moulin
    • , Mounir Maaloum
    • , Jean-François Dayen
    • , Jean-Baptiste Beaufrand
    • , Silvia Zanettini
    • , Bernard Doudin
    •  & Nicolas Giuseppone
  • Article |

    Nature synthesizes proteins and nucleic acids by polymerization methods that use well-regulated and segregated templates. Now, synthetic block-copolymer templates have been designed to assemble in a biomimetic fashion to segregate, and thus control, the synthetic radical polymerization of complementary nucleobase-containing vinyl monomers, to yield high-molecular-weight, low-polydispersity polymer chains.

    • Ronan McHale
    • , Joseph P. Patterson
    • , Per B. Zetterlund
    •  & Rachel K. O'Reilly
  • Article |

    Copper and bipyridine (bpy) self-assemble in aqueous solutions at high pH into an active electrocatalyst for the oxidation of water to O2, one of the great challenges in energy catalysis. These solutions contain primarily (bpy)Cu(OH)2, and are robust and active catalysts, albeit at high overpotentials.

    • Shoshanna M. Barnett
    • , Karen I. Goldberg
    •  & James M. Mayer
  • Article |

    Acyclic cucurbituril-type molecular containers have been found to increase the solubility of insoluble pharmaceutical agents in water by up to 2,750-fold. In vitro and in vivo toxicology studies suggest that the containers are well tolerated, and paclitaxel solubilized in this manner efficiently kills HeLa and SK-OV-3 cancer cells.

    • Da Ma
    • , Gaya Hettiarachchi
    • , Duc Nguyen
    • , Ben Zhang
    • , James B. Wittenberg
    • , Peter Y. Zavalij
    • , Volker Briken
    •  & Lyle Isaacs

In Your Element

  • In Your Element |

    Many chemical elements behave quite differently depending on the compound they are found in, but Matt Rattley argues that bromine does so in a particularly striking manner.

    • Matt Rattley

Correction

Corrigendum