Volume 3 Issue 12, December 2011

Volume 3 Issue 12

The cover image shows an artist's impression of cells growing in a photochemically modifiable hydrogel matrix. In the system described by Cole DeForest and Kristi Anseth, the hydrogel is formed using a biocompatible copper-free click reaction. It is then modified using a combination of two orthogonal photochemical reactions to investigate how cells spread and form interactions in response to various biochemical and biomechanical stimuli during growth.Article p925IMAGE: ERIC CLAEYS, COLE DEFOREST & KRISTI ANSETHCOVER DESIGN: ALEX WING

Editorial

  • Editorial |

    To join in with the International Year of Chemistry celebrations, we launched a competition earlier this year inviting aspiring science communicators to write an essay about one of seven elements.

Thesis

  • Thesis |

    Michelle Francl wonders how much time chemists should spend learning history.

    • Michelle Francl

Books and Arts

Research Highlights

Blogroll

News and Views

  • News & Views |

    The scope of dynamic combinatorial chemistry is somewhat limited by the small number of predictably reversible reactions. Now, secondary alcohols are shown to quickly and reversibly react with iminium ions to form hemiaminal ethers, opening up opportunites for their use in the construction of complex — and functional — dynamic architectures.

    • Ognjen Š. Miljanić
  • News & Views |

    Thermodynamic measurements show that the most stable structural form of a number of proteins under cellular conditions is fibrillar, implying that their functional states may only be metastable.

    • D. Thirumalai
    •  & G. Reddy
  • News & Views |

    Cross-coupling between a racemic secondary alkyl halide and an alkyl borane to produce an enantioenriched alkyl–alkyl product is one of the final substrate combinations to succumb to the synthetically powerful Suzuki–Miyaura methodology.

    • Ben W. Glasspoole
    •  & Cathleen M. Crudden
  • News & Views |

    Mutating RNA one nucleotide at a time and measuring the impact of this on its chemical reactivity provides a strategy for determining its three-dimensional structure, and from there, hopefully, its function.

    • Katja Petzold
    •  & Hashim M. Al-Hashimi
  • News & Views |

    Autonomous propulsion of microparticles using catalytic olefin polymerization, and directional rotation of a molecule on a metal surface using electrons from the tip of a scanning tunnelling microscope.

    • Ben Feringa

Perspective

  • Perspective |

    Contemporary macromolecular chemistry and physics offer interesting options for making, characterizing and manipulating single polymer chains. Although it is not yet possible to emulate the structural control and functional ability of biopolymers, recent advances have opened up interesting avenues for applications of these synthetic systems in microelectronics, photovoltaics, catalysis and biotechnology.

    • Makoto Ouchi
    • , Nezha Badi
    • , Jean-François Lutz
    •  & Mitsuo Sawamoto

Articles

  • Article |

    Cell-laden synthetic hydrogels — formed via a copper-free click reaction between a poly(ethylene glycol) tetra-cyclooctyne and a peptide-diazide — provide a platform to investigate the cells' response to various stimuli during growth. The hydrogel's biochemical aspects are readily controlled by a thiol-ene photocoupling reaction initiated with visible light, whereas the biomechanical properties of the network are altered via a UV-mediated photodegradation.

    • Cole A. DeForest
    •  & Kristi S. Anseth
  • Article |

    ‘Roaming’ is a recently discovered reaction dynamics phenomenon in which a molecule undergoes frustrated dissociation to radicals, followed by an intramolecular abstraction reaction. An imaging study, with associated high-level ab initio calculations, has now shown that ‘roaming-mediated isomerization’ plays a key role in the photodissociation of nitrobenzene.

    • Michael L. Hause
    • , Nuradhika Herath
    • , Rongshun Zhu
    • , M. C. Lin
    •  & Arthur G. Suits
  • Article |

    The polyprenylated polycyclic acylphloroglucines (PPAPs) are a family of natural products in which a common core is decorated with four different substituents. Here, a synthetic strategy is presented that separates the core building steps from the core decorating steps, offering a general solution to the synthesis of these natural products that will allow investigation of their biological activities.

    • Nicole Biber
    • , Katrin Möws
    •  & Bernd Plietker
  • Article |

    The reversible covalent binding of mono-alcohols with high affinity is challenging because of their poor nucleophilicity. A multi-component assembly has now been used to achieve reversible binding of secondary alcohols through iminium activation and product stabilization. Moreover, such assemblies can be used to determine alcohol chirality and enantiomeric excess.

    • Lei You
    • , Jeffrey S. Berman
    •  & Eric V. Anslyn
  • Article |

    One-dimensional wires with metal–metal bonding have been studied for more than a century, but control over structure and properties has remained challenging. Here, palladium–palladium bonding is used to make one-dimensional wires with lengths of up to 750 nm in solution, whose molecular structures can be rationally modified.

    • Michael G. Campbell
    • , David C. Powers
    • , Jean Raynaud
    • , Michael J. Graham
    • , Ping Xie
    • , Eunsung Lee
    •  & Tobias Ritter
  • Article |

    Non-coding RNAs are ubiquitous biomolecules with intricate three-dimensional folds that are difficult to characterize. This Article presents an information-rich strategy for inferring RNA structure by combining nucleotide-by-nucleotide mutagenesis with single-nucleotide-resolution chemical mapping.

    • Wipapat Kladwang
    • , Christopher C. VanLang
    • , Pablo Cordero
    •  & Rhiju Das
  • Article |

    Intracellular biothiols can degrade nanoparticle monolayers, compromising the function of these potentially promising tools. Here, we describe a label-free method for quantifying the intracellular stability of quantum dot monolayers, using laser desorption/ionization mass spectrometry coupled with inductively coupled plasma mass spectrometry.

    • Zheng-Jiang Zhu
    • , Yi-Cheun Yeh
    • , Rui Tang
    • , Bo Yan
    • , Joshua Tamayo
    • , Richard W. Vachet
    •  & Vincent M. Rotello
  • Article |

    The natural product fumagillol has been exploited as a stereochemically rich scaffold for the synthesis of a structurally unique, chemically diverse library with chemotypes distinctly different from the parent structure. Thus, fumagillol has been remodelled into a diverse array of isoindoles, isoquinolines, furans, mopholinones and benzoxazepines.

    • Bradley R. Balthaser
    • , Meghan C. Maloney
    • , Aaron B. Beeler
    • , John A. Porco Jr
    •  & John K. Snyder

In Your Element

  • In Your Element |

    Sodium, ubiquitous on Earth in living organisms, oceans and minerals — all the way to table salt — may seem like one of the more ordinary elements. Margit S. Müller highlights why we, like the fairytale king, should not take it for granted.

    • Margit S. Müller