Volume 12 Issue 9, September 2020

Volume 12 Issue 9

Observing ring opening

Light-induced ring-opening/closing reactions are important in many key processes in nature — such as the synthesis of natural products — and are attracting interest in other areas such as optical data storage and potential medical applications. Rolles, Curchod, Ashfold and colleagues have now studied the dynamics of the ring opening of a model heterocycle, thiophenone, using femtosecond photoelectron spectroscopy combined with ab initio theory, enabling the visualization of rich dynamics in both the excited and ground electronic states. The cover image shows a ‘heat map’ in the background that represents the photoproducts in a 2D space — with the C–S bond length represented on the vertical axis and the CCS angle along the horizontal axis — overlayed with drawings of the photoproducts and the initial thiophenone being hit by the 'laser'. The white lines follow the smoothed paths of reaction trajectories.

Rolles Article

IMAGE: Lea M. Ibele, Durham University. COVER DESIGN: Tulsi Voralia.

Comment

  • Comment |

    Valuing diversity leads to scientific excellence, the progress of science and, most importantly, it is simply the right thing to do. We must value diversity not only in words, but also in actions.

    • César A. Urbina-Blanco
    • , Safia Z. Jilani
    • , Isaiah R. Speight
    • , Michael J. Bojdys
    • , Tomislav Friščić
    • , J. Fraser Stoddart
    • , Toby L. Nelson
    • , James Mack
    • , Renã A. S. Robinson
    • , Emanuel A. Waddell
    • , Jodie L. Lutkenhaus
    • , Murrell Godfrey
    • , Martine I. Abboud
    • , Stephen O. Aderinto
    • , Damilola Aderohunmu
    • , Lučka Bibič
    • , João Borges
    • , Vy M. Dong
    • , Lori Ferrins
    • , Fun Man Fung
    • , Torsten John
    • , Felicia P. L. Lim
    • , Sarah L. Masters
    • , Dickson Mambwe
    • , Pall Thordarson
    • , Maria-Magdalena Titirici
    • , Gabriela D. Tormet-González
    • , Miriam M. Unterlass
    • , Austin Wadle
    • , Vivian W.-W. Yam
    •  & Ying-Wei Yang
  • Comment |

    Stay-at-home policies invoked in response to COVID-19 have led to well-publicized drops in some air pollutants. The extent to which such reductions translate to improved air quality is dictated by not only emissions and meteorology, but also chemical transformations in the atmosphere.

    • Jesse H. Kroll
    • , Colette L. Heald
    • , Christopher D. Cappa
    • , Delphine K. Farmer
    • , Juliane L. Fry
    • , Jennifer G. Murphy
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Thesis

  • Thesis |

    There are plenty of online resources to ensure that learning can continue for students who cannot access universities during a pandemic, but what options are there for practical aspects of science courses? Daren J. Caruana, Christoph G. Salzmann and Andrea Sella offer a manifesto for home-based experiments.

    • Daren J. Caruana
    • , Christoph G. Salzmann
    •  & Andrea Sella

News & Views

  • News & Views |

    Controlling the formation of ordered and predictable patterns in dissipative reaction–diffusion processes is challenging. Now, liquid vibrations induced by audible sound have been shown to direct the formation of spatiotemporal patterns in switchable chemical systems and assemblies.

    • Charalampos G. Pappas
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    White phosphorus is a prominent source of P atoms but has remained difficult to activate without using transition metals. Now, a bidentate ligand based on silicon(ii) donors has successfully stabilized a P2 moiety, and the resulting complex acts as a transfer reagent for P anions.

    • David Scheschkewitz
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    An approach to design artificial intrinsically disordered proteins using a short peptide as a repeating unit has been reported. This design enables the phase behaviour of the protein to be finely tuned inside cells and enabled the formation of phase-separated condensates that can modulate chemical reactions.

    • Soumik Ray
    •  & Samir K. Maji
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    Recent research has shown that vibronic coherences are one of the primary drivers for ultrafast light-induced processes. Now, ultrafast spectroscopy has been used to uncover vibronic coherences in the excited-state dynamics of an iron complex, leading to its redesign and the drastic prolonging of its excited-state lifetime.

    • Julia A. Weinstein
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    Enzymes that methylate using S-adenosyl-l-methionine — nature’s methyliodide — are abundant and often promiscuous; however, a preference for alkylation over methylation has been neither observed in nature nor engineered. Now, carboxymethylation has been demonstrated using engineered methyltransferases.

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Meeting Reports

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    Chemical systems can show complex behaviour that is not seen in individual molecules or reactions. Helena S. Azevedo, Sarah L. Perry, Peter A. Korevaar, and Dibyendu Das report on the emergence of this complex behaviour, which was discussed at the Virtual Symposium on Systems Chemistry

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    • , Sarah L. Perry
    • , Peter A. Korevaar
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Articles

  • Article |

    Photoinduced isomerization reactions, including ring-opening reactions, lie at the heart of many chemical processes in nature. The pathway and dynamics of the ring opening of a model heterocycle have now been investigated by femtosecond photoelectron spectroscopy combined with ab initio theory, enabling the visualization of rich dynamics in both the ground and excited electronic states.

    • Shashank Pathak
    • , Lea M. Ibele
    • , Rebecca Boll
    • , Carlo Callegari
    • , Alexander Demidovich
    • , Benjamin Erk
    • , Raimund Feifel
    • , Ruaridh Forbes
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    • , Luca Giannessi
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    • , Robert Mason
    • , Oksana Plekan
    • , Kevin C. Prince
    • , Arnaud Rouzée
    • , Richard J. Squibb
    • , Jan Tross
    • , Michael N. R. Ashfold
    • , Basile F. E. Curchod
    •  & Daniel Rolles
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    White phosphorus (P4) is very reactive but is relatively difficult to activate without relying on transition metals. Now, it has been shown that the degradation of P4 can be mediated by two divalent silicon atoms in a bis(silylene) scaffold to give a diphosphorus complex that can be further functionalized and also act as a P transfer agent.

    • Yuwen Wang
    • , Tibor Szilvási
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    Patterns formed by artificial out-of-equilibrium chemical oscillating networks (such as the Belousov–Zhabotinsky reaction) are difficult to control with any precision. Now, it has been shown that low-intensity audible sound can be used to generate spatiotemporal patterns with a programmable distribution of redox- and pH-responsive chemical systems and supramolecular assemblies in solution.

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    • , Rahul Dev Mukhopadhyay
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    • , Zi-Hua Lin
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