Volume 9 Issue 1, January 2017

Volume 9 Issue 1

Chiral recognition is a useful means of endowing molecules with directional binding interactions and can be used to control the modular construction of larger assemblies. Andrew I. Cooper, Graeme M. Day and co-workers have now adopted this strategy to show that porous organic cages can be packed together in a rational manner to form porous 1D nanotubes and pillared 3D frameworks (as stylized on the cover). This design principle thus permits the synthesis of reticular networks from purely organic molecules. Article p17; News & Views p6 IMAGE: ADAM KEWLEY, UNIVERSITY OF CAMBRIDGE COVER DESIGN: NADIA NELSON

Commentary

  • Commentary |

    As compared to the drug discovery process, the development of new 18F PET tracers lacks a well-established pipeline that advances compounds from academic research to candidacy for (pre)clinical imaging. In order to bridge the gaps between methodological advances and clinical success, we must rethink the development process from training to implementation.

    • Michael G. Campbell
    • , Joel Mercier
    • , Christophe Genicot
    • , Véronique Gouverneur
    • , Jacob M. Hooker
    •  & Tobias Ritter

Thesis

  • Thesis |

    Michael Donnay and Michelle Francl want chemists to share the stories behind the work they do, and not be afraid to identify the heroines and heroes — and their epic adventures — that paved the way.

    • Michelle Francl
    •  & Michael Donnay

News and Views

  • News & Views |

    The design and prediction of network topology is challenging, even when the components' principle interactions are strong. Now, frameworks with relatively weak 'chiral recognition' between organic building blocks have been synthesized and rationalized in silico — an important development in the reticular synthesis of molecular crystals.

    • Caroline Mellot-Draznieks
    •  & Anthony K. Cheetham
  • News & Views |

    Nature oxidizes biosynthetic intermediates into structurally and functionally diverse peptides. An iron-catalysed C–H oxidation mimics this approach in the lab, enabling chemists to synthesize structural analogues with ease.

    • Sean Bartlett
    •  & David R. Spring

Perspective

  • Perspective |

    Although metal–organic frameworks are often seen as rigid crystalline structures, there is growing evidence that large-scale flexibility, the presence of defects, and long-range disorder are not the exception, but rather the norm. Here we propose that these concepts are inescapably intertwined, and the interfaces between them offer prospects for enhancement of materials' functionalities.

    • Thomas D. Bennett
    • , Anthony K. Cheetham
    • , Alain H. Fuchs
    •  & François-Xavier Coudert

Articles

  • Article |

    Porous molecular crystals have desirable properties, but are hard to form with the level of structural control seen for extended framework materials. Now, a ‘mix-and-match’ chiral recognition strategy has been used to form reticular porous supramolecular nanotubes and 3D networks, providing a blueprint for pore design in molecular crystals.

    • A. G. Slater
    • , M. A. Little
    • , A. Pulido
    • , S. Y. Chong
    • , D. Holden
    • , L. Chen
    • , C. Morgan
    • , X. Wu
    • , G. Cheng
    • , R. Clowes
    • , M. E. Briggs
    • , T. Hasell
    • , K. E. Jelfs
    • , G. M. Day
    •  & A. I. Cooper
  • Article |

    Transition-metal-catalysed direct C(sp3)−H functionalization of primary aliphatic amines is an attractive – but elusive – process that could provide efficient access to biologically and pharmaceutically important compounds. Now, a palladium-catalysed γ-arylation of primary alkylamines is achieved using an inexpensive, catalytic and transient directing group.

    • Yongbing Liu
    •  & Haibo Ge
  • Article |

    Lateral anchoring of heteromolecules to graphene paves the way for the creation of hybrid materials with tunable properties. Now, following a surface-assisted dehydrogenative coupling reaction, the edges of graphene on silver have been functionalized with porphines. This enables the assembly of well-defined multifunctional graphene-based nanostructures.

    • Yuanqin He
    • , Manuela Garnica
    • , Felix Bischoff
    • , Jacob Ducke
    • , Marie-Laure Bocquet
    • , Matthias Batzill
    • , Willi Auwärter
    •  & Johannes V. Barth
  • Article |

    There is increasing evidence that highly dynamic, polydisperse peptide oligomers are the toxic species in amyloid-related diseases such as Alzheimer's and Parkinson's. Now, the secondary structure of individual amyloid oligomers has been analysed directly for the first time using a combination of ion-mobility spectrometry–mass spectrometry and gas-phase infrared spectroscopy.

    • Jongcheol Seo
    • , Waldemar Hoffmann
    • , Stephan Warnke
    • , Xing Huang
    • , Sandy Gewinner
    • , Wieland Schöllkopf
    • , Michael T. Bowers
    • , Gert von Helden
    •  & Kevin Pagel
  • Article |

    An artificial aldolase has been optimized using an ultrahigh-throughput microfluidic screening assay. The evolved enzyme exhibits excellent stereoselectivity and broad substrate scope. Structural studies suggest that a Lys-Tyr-Asn-Tyr catalytic tetrad, which emerged during directed evolution, is responsible for the >109 rate enhancement achieved by this catalyst.

    • Richard Obexer
    • , Alexei Godina
    • , Xavier Garrabou
    • , Peer R. E. Mittl
    • , David Baker
    • , Andrew D. Griffiths
    •  & Donald Hilvert
  • Article |

    Metal surfaces have been believed to be catalytic, but the mechanism of catalysis is unknown. Now, graphene nanoribbons (GNRs) can be grown on Au(111) from a ‘Z-bar-linkage' precursor through a conformation-controlled mechanism. Chemical vapour deposition of precursors adopting a chiral conformation produced homochiral polymers, which are dehydrogenated to form GNRs.

    • Hiroshi Sakaguchi
    • , Shaotang Song
    • , Takahiro Kojima
    •  & Takahiro Nakae
  • Article |

    The existence of linear scaling relations between the adsorption energies of reaction intermediates on transition-metal surfaces prevents their independent optimization and limits catalytic activity. It has now been shown that using a catalytic LiH site alongside a transition-metal catalyst can break these intrinsic scaling relations, leading to unprecedented lower-temperature ammonia-synthesis activity.

    • Peikun Wang
    • , Fei Chang
    • , Wenbo Gao
    • , Jianping Guo
    • , Guotao Wu
    • , Teng He
    •  & Ping Chen
  • Article |

    Control over the selectivity of chemical reactions and biological molecules requires an intimate understanding of how conformation impacts reactivity. It is now shown that the trans conformer of trifluoromethylhydroxycarbene preferentially rearranges through a quantum-mechanical hydrogen-tunnelling pathway, whereas its cis conformer is unreactive.

    • Artur Mardyukov
    • , Henrik Quanz
    •  & Peter R. Schreiner
  • Article |

    Crystals grow from nuclei. In systems where nuclei are nanometre-sized and form quickly, it is difficult to determine the mechanism of their formation. Now, through in situ TEM, the demixing of a supersaturated aqueous gold solution into metastable gold-poor and gold-rich liquid phases is observed, the latter yielding stable clusters that become nuclei for nanocrystal growth.

    • N. Duane Loh
    • , Soumyo Sen
    • , Michel Bosman
    • , Shu Fen Tan
    • , Jun Zhong
    • , Christian A. Nijhuis
    • , Petr Král
    • , Paul Matsudaira
    •  & Utkur Mirsaidov
  • Article |

    A family of fluorescent molecular rotors has been developed and their mechanism for emission understood. It has been observed that, although most fluorescent molecules emit from their lowest energy excited state, S1 (in accordance with Kasha's rule), BODIHY dyes do not. Furthermore, their fluorescence is enhanced through restricted rotor rotation, which suppresses internal conversion to the dark S1 state.

    • Hai Qian
    • , Morgan E. Cousins
    • , Erik H. Horak
    • , Audrey Wakefield
    • , Matthew D. Liptak
    •  & Ivan Aprahamian
  • Article |

    FeFe hydrogenases are highly efficient H2 producing enzymes; however, they can be inactivated by O2. Now, a mechanism for O2 diffusion within FeFe hydrogenases and its reactions at the active site of the enzyme has been proposed. These findings could help with the design of hydrogenase mutants with increased resistance to oxidative damage.

    • Adam Kubas
    • , Christophe Orain
    • , David De Sancho
    • , Laure Saujet
    • , Matteo Sensi
    • , Charles Gauquelin
    • , Isabelle Meynial-Salles
    • , Philippe Soucaille
    • , Hervé Bottin
    • , Carole Baffert
    • , Vincent Fourmond
    • , Robert B. Best
    • , Jochen Blumberger
    •  & Christophe Léger

In Your Element

  • In Your Element |

    Nadezda V. Tarakina and Bart Verberck explore the colourful history and assets of element 48.

    • Nadezda V. Tarakina
    •  & Bart Verberck