Volume 5 Issue 1, January 2013

Volume 5 Issue 1

The proton-coupled redox reactions of a class of expanded porphyrins known as rosarins have been studied by an international collaboration between researchers based in Korea, Japan, the USA and India. A near-planar 24 π-electron antiaromatic rosarin is reduced in a stepwise manner when treated with HI to first give a non-aromatic 25 π-electron system and then a 26 π-electron aromatic species. Artistic representations of the ortho-phenylene-bridged rosarin used in this study are repeated in the central window of the image shown on the cover.Article p15IMAGES: CATHEDRAL © ISTOCKPHOTO.COM/THINKSTOCK; ROSARIN © ANGEL SYRETTCOVER DESIGN: ALEX WING

Thesis

  • Thesis |

    Bruce Gibb discusses how and why chemists name reactions and molecules — and what makes such monikers stick.

    • Bruce C. Gibb

Research Highlights

Blogroll

News and Views

  • News & Views |

    The metal cofactors responsible for the activity of CDK2 — a representative member of the kinase superfamily of enzymes — have now been shown to also have inhibitory effects during the catalytic cycle.

    • Ivaylo Ivanov
  • News & Views |

    Quantum mechanics rears its head in many places and one of them is inorganic chemistry, where the electronic spin associated with unpaired electrons has a profound influence. This was the topic of the 2012 CECAM workshop.

    • Miquel Costas
    •  & Jeremy N. Harvey
  • News & Views |

    Natural products contain a range of chemical structures optimized for biological interactions. Fragmenting these compounds could help to combine this diversity with the broad coverage of chemical space offered by fragment-based drug discovery, and help to improve the efficiency with which screening hits can become successful drugs.

    • Brian K. Shoichet
  • News & Views |

    The biosynthesis of peptidoglycan is an important step in bacterial cell division and cell-wall maturation. Now it has been shown that fluorescent D-amino acids can be used to label the peptidoglycan cell wall of living bacteria, providing a new tool to study this important process.

    • Timothy D. H. Bugg
  • News & Views |

    An experimental set-up has been devised to monitor mechanochemical processes in situ, yielding direct insights into mechanistic and kinetic aspects of solid-state reactions that are promoted by grinding, such as the synthesis of metal–organic frameworks.

    • Kenneth D. M. Harris

Articles

  • Article |

    A 24 π-electron antiaromatic hexaphyrin derivative (rosarin) with a near-planar geometry enforced by bridging phenylene groups has been shown to undergo a proton-coupled electron transfer reduction when treated with certain protic acids. The reduction proceeds in a stepwise fashion to give first a 25 π-electron non-aromatic system and then a 26 π-electron aromatic ring.

    • Masatoshi Ishida
    • , Soo-Jin Kim
    • , Christian Preihs
    • , Kei Ohkubo
    • , Jong Min Lim
    • , Byung Sun Lee
    • , Jung Su Park
    • , Vincent M. Lynch
    • , Vladimir V. Roznyatovskiy
    • , Tridib Sarma
    • , Pradeepta K. Panda
    • , Chang-Hee Lee
    • , Shunichi Fukuzumi
    • , Dongho Kim
    •  & Jonathan L. Sessler
  • Article |

    Natural products populate areas of chemical space not occupied by average synthetic molecules. Here, an analysis of more than 180,000 natural product structures results in a library of 2,000 natural-product-derived fragments, which resemble the properties of the natural products themselves and give access to novel inhibitor chemotypes.

    • Björn Over
    • , Stefan Wetzel
    • , Christian Grütter
    • , Yasushi Nakai
    • , Steffen Renner
    • , Daniel Rauh
    •  & Herbert Waldmann
  • Article |

    The infrared spectra of gas-phase protonated water clusters and protonated liquid water have been calculated from molecular simulations using a ‘clusters-in-liquid’ approach, which is restricted to a selected set of charged atoms. The infrared absorption due to the central proton in the H2O···H+···OH2 moiety is found near 1,740 cm−1.

    • Waldemar Kulig
    •  & Noam Agmon
  • Article |

    The selective dissociation and formation of different functional groups in a single organic molecule may prove useful for making nanoscale devices and offer new opportunities for studying changes in electronic structure. It has now been shown that bond-selective chemistry can be induced and visualized at the submolecular level in a complex thiol-based molecule using a scanning tunnelling microscope.

    • Ying Jiang
    • , Qing Huan
    • , Laura Fabris
    • , Guillermo C. Bazan
    •  & Wilson Ho
  • Article |

    Supramolecular gels whose properties can be tuned through non-covalent interactions — typically metal coordination or hydrogen bonding — are attracting attention in various fields. Researchers have now shown that halogen bonding is also strong enough to be relied on; it interferes with competitive, gel-inhibitory hydrogen bonding to induce co-gelation between two urea-based components.

    • Lorenzo Meazza
    • , Jonathan A. Foster
    • , Katharina Fucke
    • , Pierangelo Metrangolo
    • , Giuseppe Resnati
    •  & Jonathan W. Steed
  • Article |

    Efficient hydrogen-evolving catalysts comprising readily available elements are needed if hydrogen is to be adopted as a clean alternative to fossil fuels. Now, a diimine–dioxime cobalt complex has been covalently attached to a carbon nanotube electrode to yield an active and robust electrocatalyst for hydrogen generation (55,000 turnovers in seven hours) from aqueous solutions.

    • Eugen S. Andreiadis
    • , Pierre-André Jacques
    • , Phong D. Tran
    • , Adeline Leyris
    • , Murielle Chavarot-Kerlidou
    • , Bruno Jousselme
    • , Muriel Matheron
    • , Jacques Pécaut
    • , Serge Palacin
    • , Marc Fontecave
    •  & Vincent Artero
  • Article |

    The in situ trapping of pyridynes is an efficient method for the generation of a variety of substituted pyridines but, until now, the method has been hampered by a lack of regiocontrol. Here, proximal halide and sulfamate substituents are shown to perturb pyridyne distortion and thus govern regioselectivities in pyridyne reactions.

    • Adam E. Goetz
    •  & Neil K. Garg
  • Article |

    Xenon is an inert element at ambient conditions but may become reactive under pressure. It has now been predicted that pressure stabilizes increasing oxidation states of Xe atoms (from Xe0 to Xe2+ to Xe4+ to Xe6+), and thus a series of compounds — XeO, XeO2 and XeO3 — become thermodynamically stable at megabar pressures.

    • Qiang Zhu
    • , Daniel Y. Jung
    • , Artem R. Oganov
    • , Colin W. Glass
    • , Carlo Gatti
    •  & Andriy O. Lyakhov
  • Article |

    Milling and grinding, long used to alter the chemical and physical properties of materials, have recently garnered interest as alternatives to traditional solution-based syntheses — but these reactions remain difficult to monitor. High-energy synchrotron X-ray radiation has now enabled the in situ observation, in real time, of solid-state transformations occurring during the mechanochemical syntheses of metal–organic frameworks.

    • Tomislav Friščić
    • , Ivan Halasz
    • , Patrick J. Beldon
    • , Ana M. Belenguer
    • , Frank Adams
    • , Simon A.J. Kimber
    • , Veijo Honkimäki
    •  & Robert E. Dinnebier

In Your Element

  • In Your Element |

    Daniel Rabinovich outlines the history, properties and uses of aluminium — one of the most versatile, pervasive and inexpensive metals today, yet it was considered a rare and costly element only 150 years ago.

    • Daniel Rabinovich

Erratum