Volume 3 Issue 11, November 2011

Volume 3 Issue 11

The cover image shows an artistic impression of the flow of energy in the wake of the solution-phase bimolecular reaction between cyclohexane and the cyano radical. This reaction was studied by David Glowacki, Jeremy Harvey and co-workers using molecular dynamics simulations to model the vibrational relaxation of the products. The more intense colours indicate fast energy exchange within the radical co-product solvent shell, whereas less intense colours indicate slower energy flow once the products have diffused away from one another within the solvent.Article p850IMAGE: BECCA ROSE AND DAVID GLOWACKICOVER DESIGN: ALEX WING

Editorial

Thesis

  • Thesis |

    The historical context in which a scientific paper is published is an important factor that should not be overlooked, suggest Qian Wang and Chris Toumey.

    • Qian Wang
    •  & Chris Toumey

Research Highlights

Blogroll

News and Views

  • News & Views |

    A tetra-intercalator compound that threads through a DNA double-helix to form a remarkably stable complex exhibits an unusual combination of sequence specificity and rapid association yet slow dissociation.

    • Adam R. Urbach
  • News & Views |

    Activating caged reactive sites in proteins using mechanical force provides a powerful approach in the study of chemical reactions, and provides greater insight into which reactions are possible and their rates.

    • Chia-Ching Chou
    •  & Markus J. Buehler
  • News & Views |

    Catalyst particles for fluid catalytic cracking are vital for the oil-refinery industry, but their activity is hard to diagnose because of their inter- and intra-particle structural inhomogeneity. With fluorescence confocal microscopy and selective staining, one can now pinpoint the catalytic activity within single catalyst particles from an industrial reactor.

    • Peng Chen
  • News & Views |

    Proton migration on membranes is a crucial step in the bioenergetics of the cell. It has typically been regarded as slow successive proton transfers between ionizable moieties within the membrane, but recent measurements suggest fast lateral diffusion in the membrane's hydration layer.

    • Noam Agmon
    •  & Menachem Gutman
  • News & Views |

    Conformational control can be used to transmit information in the form of chirality over relatively long molecular distances and could be the key to the preparation of minimalistic synthetic mimics of biological systems.

    • Jonathan Clayden

Perspective

Articles

  • Article |

    The flow of vibrational energy into reactants and out of products plays a critical role in nearly every chemical reaction. Here, a time-resolved ultrafast microscopic map of energy flow is provided for a thermal bimolecular chemical reaction that takes place in dichloromethane, a typical organic solvent.

    • David R. Glowacki
    • , Rebecca A. Rose
    • , Stuart J. Greaves
    • , Andrew J. Orr-Ewing
    •  & Jeremy N. Harvey
  • Article |

    2,2′-bipyridine ligands coordinate to metals to form chiral propeller-like complexes. Now, this chirality is shown to be controlled by the coordination of 2,2′-bipyridine ligands that bear helical oligopeptides, which incorporate chiral amino acids at positions remote from the metal centre. This chirality is further translated, via the metal centre, to other achiral-oligopeptide-containing ligands.

    • Naoki Ousaka
    • , Yuki Takeyama
    • , Hiroki Iida
    •  & Eiji Yashima
  • Article |

    Insight into the active zeolitic domains of catalyst particles used in fluid catalytic cracking is limited by the particles' complex nature, but is crucial to improving these billion dollar catalysts. Now, a staining method allows confocal fluorescence microscopy to probe within single catalyst particles, and correlate Brønsted acidity distributions to catalytic activity.

    • Inge L. C. Buurmans
    • , Javier Ruiz-Martínez
    • , William V. Knowles
    • , David van der Beek
    • , Jaap A. Bergwerff
    • , Eelco T. C. Vogt
    •  & Bert M. Weckhuysen
  • Article |

    Cellular membrane lipids play key roles in cell regulation. Here, an environmentally sensitive fluorophore is attached to a protein that binds to a key signalling lipid to produce a membrane lipid sensor. This strategy allows sensitive, quantitative, spatiotemporal imaging of the lipid concentration in mammalian cells.

    • Youngdae Yoon
    • , Park J. Lee
    • , Svetlana Kurilova
    •  & Wonhwa Cho
  • Article |

    Molecules that bind to DNA for extended periods can modulate its transcription or other biological processes. Kinetic studies on the non-covalent complex formed by a threading tetra-intercalator and a DNA double-helix have now revealed a multi-step association, and a particularly slow dissociation leading to sequence specificity and a 16-day half-life.

    • Garen G. Holman
    • , Maha Zewail-Foote
    • , Amy Rhoden Smith
    • , Kenneth A. Johnson
    •  & Brent L. Iverson
  • Article |

    Multiple redox reaction pathways exist in proteins containing several cysteines. A technique termed mechanical uncaging is now demonstrated, allowing the release of a single reactive cysteine within a protein and the unequivocal observation of subsequent thiol/disulfide exchanges. Mechanical uncaging of reactive groups is useful for studying chemical kinetics in a synchronized manner.

    • Jorge Alegre-Cebollada
    • , Pallav Kosuri
    • , Jaime Andrés Rivas-Pardo
    •  & Julio M. Fernández
  • Article |

    At water's surface, its network of hydrogen-bonds is abruptly interrupted, conferring distinct properties on interfacial water from bulk water. Understanding aqueous interfaces is essential for many environmental, technological and biophysical systems, and now the pathways and rates of energy transfer at the water/air interface are elucidated using a surface-specific ultrafast spectroscopic technique.

    • Zhen Zhang
    • , Lukasz Piatkowski
    • , Huib J. Bakker
    •  & Mischa Bonn
  • Article |

    Stereoselective Suzuki–Miyaura cross-coupling reactions involving non-benzylic secondary alkylboronates are notoriously challenging. Here, an enantioselective synthesis of 1,1-diboronyl compounds using asymmetric conjugate borylation, followed by chemoselective mono cross-coupling with inversion at the diboron centre, is used to produce highly enantioenriched benzylic or allylic boronates, which themselves are useful reagents for a number of processes.

    • Jack Chang Hung Lee
    • , Robert McDonald
    •  & Dennis G. Hall

In Your Element

  • In Your Element |

    Calcium is found throughout the solar system, the Earth's crust and oceans, and is an essential constituent of cells, shells and bones — yet it is curiously scarce in the upper atmosphere. John Plane ponders on this 25-year-old mystery.

    • John M. C. Plane