Volume 6 Issue 8, August 2014

Volume 6 Issue 8

The topology of any given metal–organic framework (MOF) is typically determined after it is made, rather than being predicted before its synthesis based on the nature of the building blocks. Now, Mohamed Eddaoudi and colleagues have discovered a new MOF topology (denoted gea), and through an analysis of its components they have replicated the same connectivity in a different MOF. The cover depicts a blueprint for this (3,18) topology as well as the molecular and supermolecular building blocks (MBB and SBB, respectively) used to construct the second framework.

Article p673

IMAGE: V. GUILLERM AND M. EDDAOUDI

COVER DESIGN: ALEX WING

Thesis

  • Thesis |

    Bruce Gibb looks back at some examples of irreproducible reactions in his own laboratory and suggests ways in which the reproducibility of chemical reactions can be maximized.

    • Bruce C. Gibb

Books and Arts

  • Books & Arts |

    • Timothy W. Lyons

Research Highlights

Blogroll

News and Views

  • News & Views |

    Self-assembled amphiphiles are more common in the realm of aqueous systems than in organic solvents. Their scope has now been expanded with the advent of 'hydrophobic amphiphiles' of π-conjugated–alkyl systems, which show various self-assembled phases similar to classical amphiphiles.

    • Albert P. H. J. Schenning
    •  & Subi J. George
  • News & Views |

    Intramolecular aliphatic C–H amination reactions are greatly sought-after for the synthesis of N-containing heterocycles, but current methods require the use of highly activated nitrogen sources. Now, aziridination and lactamization have been achieved using fully aliphatic, unactivated, secondary amines.

    • Olga V. Zatolochnaya
    •  & Vladimir Gevorgyan
  • News & Views |

    For decades chemists have focused on increasing the brightness of fluorophores. In super-resolution microscopy, however, fluorophores that preferentially exist in a non-fluorescent state, but occasionally re-arrange into a fluorescent form, can give better results.

    • Gražvydas Lukinavičius
    •  & Kai Johnsson

Perspective

  • Perspective |

    Biological systems have evolved sophisticated machinery to assemble polymeric receptors capable of molecular recognition. Although such precise levels of structural control are currently inaccessible to chemists, impressive progress has been made towards the realization of wholly synthetic analogues of antibodies and other proteins. Protein structure from H. Li et al. Biochemistry 33, 11734–11744 (1994); © American Chemical Society.

    • Clare S. Mahon
    •  & David A. Fulton

Articles

  • Article |

    It is often difficult to predict or control the topologies of metal–organic frameworks (MOFs) before synthesis. Now, the topology of a MOF has been used as an ideal blueprint for the deliberate design of a related MOF, by substitution of molecular building blocks with supermolecular building blocks. The two MOFs share the same underlying topology but have different chemical compositions.

    • Vincent Guillerm
    • , Łukasz J. Weseliński
    • , Youssef Belmabkhout
    • , Amy J. Cairns
    • , Valerio D'Elia
    • , Łukasz Wojtas
    • , Karim Adil
    •  & Mohamed Eddaoudi
  • Article |

    A self-blinking fluorophore suitable for super-resolution imaging has been developed. The blinking arises from a reversible intramolecular spirocyclization in a rhodamine-based fluorophore that switches between a fluorescent open form and a non-fluorescent closed form. The advantages over existing methodologies are demonstrated using single-molecule localization microscopy imaging inside cells.

    • Shin-nosuke Uno
    • , Mako Kamiya
    • , Toshitada Yoshihara
    • , Ko Sugawara
    • , Kohki Okabe
    • , Mehmet C. Tarhan
    • , Hiroyuki Fujita
    • , Takashi Funatsu
    • , Yasushi Okada
    • , Seiji Tobita
    •  & Yasuteru Urano
  • Article |

    Amphiphilic self-assembly usually involves molecules consisting of hydrophobic and hydrophilic segments. Now, this concept has been broadened to encompass the self-assembly of fully hydrophobic molecules that contain mutually immiscible alkyl and π-conjugated segments. Selective additives — n-alkanes or C60 — direct their assembly into various ordered and optoelectronically functional structures.

    • Martin J. Hollamby
    • , Maciej Karny
    • , Paul H. H. Bomans
    • , Nico A. J. M. Sommerdjik
    • , Akinori Saeki
    • , Shu Seki
    • , Hiroyuki Minamikawa
    • , Isabelle Grillo
    • , Brian R. Pauw
    • , Paul Brown
    • , Julian Eastoe
    • , Helmuth Möhwald
    •  & Takashi Nakanishi
  • Article |

    It is generally believed that, after being generated, an excess electron in water shrinks from a strongly delocalized to a localized state in about a picosecond. Now, these early stages in the behaviour of this electron have been observed using a combination of transient THz spectroscopy and ab initio molecular dynamics simulations.

    • Janne Savolainen
    • , Frank Uhlig
    • , Saima Ahmed
    • , Peter Hamm
    •  & Pavel Jungwirth
  • Article |

    The ability of thiyl radicals to promote reactions has been known for decades although its extension to asymmetric catalysis has only rarely been explored. Now, an organic thiyl radical catalyst with a carefully structured chiral pocket has been designed as a means to achieve highly enantioselective radical cyclizations.

    • Takuya Hashimoto
    • , Yu Kawamata
    •  & Keiji Maruoka
  • Article |

    Charge separation in oxygenic photosynthesis occurs with high quantum efficiency and is yet to be fully understood. Using two-dimensional electronic spectroscopy, coherent dynamics have now been observed in the photosystem II reaction centre, where charge separation occurs. Supporting simulations suggest that the coherences have mixed electronic–vibrational (vibronic) nature, and may enhance the rate of charge separation. Leaf image: © Michael Wesemann/Alamy.

    • Franklin D. Fuller
    • , Jie Pan
    • , Andrius Gelzinis
    • , Vytautas Butkus
    • , S. Seckin Senlik
    • , Daniel E. Wilcox
    • , Charles F. Yocum
    • , Leonas Valkunas
    • , Darius Abramavicius
    •  & Jennifer P. Ogilvie
  • Article |

    Amiloride is a widely used diuretic that blocks epithelial sodium channels (ENaCs); however, the functional role of the different ENaC isoforms is still poorly understood and no pharmacological tools exist to differentiate between them. Now, photoswitchable amilorides that enable the optical control of ENaCs, and can distinguish between different ENaC isoforms have been developed.

    • Matthias Schönberger
    • , Mike Althaus
    • , Martin Fronius
    • , Wolfgang Clauss
    •  & Dirk Trauner
  • Article |

    Strong mineral acids usually add to alkenes such that hydrogen is added to the least substituted carbon — a pattern known as Markovnikov addition. Now, using photoredox catalysis in conjunction with a redox-active hydrogen atom donor, it has been shown that this pattern can be reversed to produce otherwise difficult to access products.

    • Dale J. Wilger
    • , Jean-Marc M. Grandjean
    • , Taylor R. Lammert
    •  & David A. Nicewicz
  • Article |

    Main-group analogues to fullerene-C60 have been predicted theoretically many times. Now, B40 has been observed using photoelectron spectroscopy and, with its neutral analogue, B40, confirmed computationally. In contrast to fullerene-C60, the all-boron fullerene (or borospherene) features triangles, hexagons and heptagons, bonded uniformly by delocalized σ and π bonds over the cage surface.

    • Hua-Jin Zhai
    • , Ya-Fan Zhao
    • , Wei-Li Li
    • , Qiang Chen
    • , Hui Bai
    • , Han-Shi Hu
    • , Zachary A. Piazza
    • , Wen-Juan Tian
    • , Hai-Gang Lu
    • , Yan-Bo Wu
    • , Yue-Wen Mu
    • , Guang-Feng Wei
    • , Zhi-Pan Liu
    • , Jun Li
    • , Si-Dian Li
    •  & Lai-Sheng Wang
  • Article |

    The widespread use of fuel cells requires improved catalysts to reduce oxygen efficiently at the cathode. It is shown that model, well-characterized size-selected PtxY nanoparticles can be synthesized by the gas aggregation technique, and that they are highly active for this reaction.

    • Patricia Hernandez-Fernandez
    • , Federico Masini
    • , David N. McCarthy
    • , Christian E. Strebel
    • , Daniel Friebel
    • , Davide Deiana
    • , Paolo Malacrida
    • , Anders Nierhoff
    • , Anders Bodin
    • , Anna M. Wise
    • , Jane H. Nielsen
    • , Thomas W. Hansen
    • , Anders Nilsson
    • , Ifan E. L. Stephens
    •  & Ib Chorkendorff
  • Article |

    Although widely used to form bridged ring systems, certain intramolecular Diels–Alder reactions are hampered by the strain inherent in forming an sp2-carbon at a bridgehead position. Now, an alternative strategy has been described to access these bridged ring systems through the C–C activation and coupling of cyclobutanones with olefins.

    • Haye Min Ko
    •  & Guangbin Dong

In Your Element

  • In Your Element |

    Anders Lennartson muses on molybdenum and its essential role in catalysing reactions from the bacterial to the industrial scale.

    • Anders Lennartson

Erratum