Oleksandr

Space, finally! The explicit investigation of perylenediimides for anion–π catalysis reveals a remarkably rich picture dominated by giant quadrupole moments, space to accommodate larger transformations, highest enantioselectivities so far, and decreasing activity with increasing twist.

[Communication]
Chao Wang, François N. Miros, Jiri Mareda, Naomi Sakai, Stefan Matile
Angew. Chem. Int. Ed., October 14, 2016, DOI: 10.1002/anie.201608842. Read article

Nature Chemistry. doi:10.1038/nchem.2625

Authors: Hongwei Zhou, Changguo Xue, Philipp Weis, Yasuhito Suzuki, Shilin Huang, Kaloian Koynov, Günter K. Auernhammer, Rüdiger Berger, Hans-Jürgen Butt & Si Wu

Reversibly inducing solid-to-liquid transitions of polymers at room temperature represents a challenge for enhanced processability and applications of polymers. Now, three azopolymers have been shown to exhibit photoswitchable glass transition temperatures, resulting in reversible, solid-to-liquid transitions. Light exposure can heal cracks in hard azopolymers, reduce surface roughness of azopolymer films and control azopolymer adhesion.

I move in: A tetrakis(3-pyridyl)ethylene cavitand reacts with silver tosylate forming a dimeric capsule through four [N⋅⋅⋅Ag⁺⋅⋅⋅N] coordination bonds. Treatment of this Ag-capsule with I₂ leads, via precipitation of AgI, to the corresponding [N⋅⋅⋅I⁺⋅⋅⋅N] halogen-bonded capsule.

[Communication]
Lotta Turunen, Ulrike Warzok, Rakesh Puttreddy, Ngong Kodiah Beyeh, Christoph A. Schalley, Kari Rissanen
Angew. Chem. Int. Ed., October 06, 2016, DOI: 10.1002/anie.201607789. Read article

Marcin A. Majewski, Yongseok Hong, Prof. Tadeusz Lis, Dr. Janusz Gregoliński, Prof. Piotr J. Chmielewski, Dr. Joanna Cybińska, Prof. Dongho Kim and Prof. Marcin Stępień

A non-Euclidean belt: Octulene, the largest coronoid ring reported to date, features a saddle-shaped aromatic hydrocarbon ring that fits on a hyperbolic surface. The large central cavity, in spite of its low electrostatic potential, acts as an anion receptor in nonpolar media, with a particularly good affinity for the chloride anion.

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Autocatalytic chemical reactions are widely studied as models of biological processes and to better understand the origins of life on Earth. Minimal self-reproducing amphiphiles have been developed in this context and as an approach to de novo “bottom–up” synthetic protocells. How chemicals come together to produce living systems, however, remains...

A chemical reaction network for small molecules is reported that provides a rapid adaptation response to out-of-equilibrium conditions inside an evaporating droplet. The chemical network provides control over the molecular constitution and spatial arrangement of the deposited solute.

[Communication]
Joseph J. Armao, Jean-Marie Lehn
Angew. Chem. Int. Ed., October 04, 2016, DOI: 10.1002/anie.201606546. Read article

Nature Chemistry. doi:10.1038/nchem.2617

Authors: Yan Qiao, Mei Li, Richard Booth & Stephen Mann

The chemical construction of compartmentalized colloidal objects with biomimetic functions and collective properties is a key challenge in synthetic protocell research. Now, an interacting binary community of protocells has been designed to display artificial predatory behaviour in which protease-containing coacervate microdroplets obliterate a population of proteinosomes, and capture a chemical payload via a simple trafficking process.

Autocatalytic, bistable, oscillatory networks of biologically relevant organic reactions

Nature 537, 7622 (2016). doi:10.1038/nature19776

Authors: Sergey N. Semenov, Lewis J. Kraft, Alar Ainla, Mengxia Zhao, Mostafa Baghbanzadeh, Victoria E. Campbell, Kyungtae Kang, Jerome M. Fox & George M. Whitesides

Networks of organic chemical reactions are important in life and probably played a central part in its origin. Network dynamics regulate cell division, circadian rhythms, nerve impulses and chemotaxis, and guide the development of organisms. Although out-of-equilibrium networks of chemical reactions have the potential to display emergent network dynamics such as spontaneous pattern formation, bistability and periodic oscillations, the principles that enable networks of organic reactions to develop complex behaviours are incompletely understood. Here we describe a network of biologically relevant organic reactions (amide formation, thiolate–thioester exchange, thiolate–disulfide interchange and conjugate addition) that displays bistability and oscillations in the concentrations of organic thiols and amides. Oscillations arise from the interaction between three subcomponents of the network: an autocatalytic cycle that generates thiols and amides from thioesters and dialkyl disulfides; a trigger that controls autocatalytic growth; and inhibitory processes that remove activating thiol species that are produced during the autocatalytic cycle. In contrast to previous studies that have demonstrated oscillations and bistability using highly evolved biomolecules (enzymes and DNA) or inorganic molecules of questionable biochemical relevance (for example, those used in Belousov–Zhabotinskii-type reactions), the organic molecules we use are relevant to metabolism and similar to those that might have existed on the early Earth. By using small organic molecules to build a network of organic reactions with autocatalytic, bistable and oscillatory behaviour, we identify principles that explain the ways in which dynamic networks relevant to life could have developed. Modifications of this network will clarify the influence of molecular structure on the dynamics of reaction networks, and may enable the design of biomimetic networks and of synthetic self-regulating and evolving chemical systems.

The spin within: A carefully designed triarylphosphine oxide scaffold with sterically demanding spirofluorenyl moieties undergoes chemical one-electron reduction at its phosphoryl moiety. The unique stability of the formed radical anion enables the isolation and X-ray crystallographic characterization of this hitherto elusive species.

[Communication]
Tobias A. Schaub, Eva M. Zolnhofer, Dominik P. Halter, Tatyana E. Shubina, Frank Hampel, Karsten Meyer, Milan Kivala
Angew. Chem. Int. Ed., September 27, 2016, DOI: 10.1002/anie.201605963. Read article

Nature Chemistry. doi:10.1038/nchem.2608

Authors: Jia-Cheng Chang, Shin-Han Tseng, Chien-Chen Lai, Yi-Hung Liu, Shie-Ming Peng & Sheng-Hsien Chiu

By exploiting structural rigidity, coordination geometries and bond rotational barriers that disfavour the formation of smaller homologues, molecular switches based on [c3] and [c4]daisy chains have been assembled selectively; they display muscle-like motion in multiple dimensions with changes in length of approximately 23% and 36%, respectively.

Should I stay or should I go? Static and dynamic sheets are formed from selective self-assembly of geometric macrocycle isomers based on anthracene units. The self-assembly of the cis isomer generates static planar sheets (left), whereas the trans isomer forms dynamic rolled sheets (right), which are reversibly unrolled upon stimulation by a thermal signal.

[Communication]
Yanqiu Wang, Yongju Kim, Myongsoo Lee
Angew. Chem. Int. Ed., September 16, 2016, DOI: 10.1002/anie.201607143. Read article

Switching on catalysis: A new class of synthetic receptors exhibit enzyme-like properties in organic solvents. Their catalytic activity (see picture; green arrow) can be turned on by a size and shape match of the substrate with the binding pocket. The electrostatic environment of the active site can be further modulated using cationic regulators (blue arrow).

[Communication]
Yupu Qiao, Long Zhang, Jia Li, Wei Lin, Zhenqiang Wang
Angew. Chem. Int. Ed., September 16, 2016, DOI: 10.1002/anie.201606847. Read article