Table of contents



Cover story p147


As the saying goes, a picture is worth a thousand words, but when that picture appears on the front cover of a scientific journal, that estimate is probably a little on the low side.

Subject Category: General chemistry



Virtual conferences becoming a reality pp148 - 152

Christopher J. Welch, Sanjoy Ray, Jaime Melendez, Thomas Fare & Martin Leach


Traditional scientific conferences can be costly and time-consuming, and certainly aren't 'green', with participants travelling long distances to attend. Are there advantages to meetings held in the virtual world, and can they really offer equally satisfying — or even better — experiences compared with the real world?

Subject Category: General chemistry


Books and Arts

Highs and lows p153

David Nichols reviews Turn On and Tune In: Psychedelics, Narcotics and Euphoriants by John Mann



Research Highlights

Our choice from the recent literature pp154 - 155


Blogroll: Lessons learnt p155



News and Views

Chemical topology: Tying up some loose ends pp156 - 157

Edward E. Fenlon


A linear molecule containing three bipyridine ligands can be wrapped around a single metal-ion template to form an open-knot complex. The loose ends of the knot can be 'tied' together through esterification or olefin-metathesis reactions to form closed knots that do not unravel when the metal template is removed.

Subject Categories: Organic chemistry | Supramolecular chemistry

See also: Article by Guo et al.

Single-molecule spectroscopy: Caught in a trap pp157 - 159

Peter Dedecker & Johan Hofkens


Monitoring the dynamics of a single molecule is impeded by their motion in solution, and immobilizing them without changing their properties is problematic. By using a trapping method that counteracts a molecule's Brownian motion, the complex dynamics of a fluorescent protein, allophycocyanin, have been investigated.

Subject Categories: Physical chemistry | Photochemistry

See also: Article by Goldsmith & Moerner

Natural-product synthesis: Stitching together palau'amine pp159 - 160

Daniel Romo


The long-awaited first total synthesis of the structurally intriguing natural product palau'amine has now been achieved. The synthesis features cascade reactions and an 'across ring' stitching of a 'macropalau'amine', and sets the bar for future efforts towards an enantioselective variant.

Subject Categories: Organic chemistry | Synthesis

Liesegang rings: Nanoparticles ring the changes p160

Neil Withers


Subject Categories: Nanotechnology | Physical chemistry

Ion-exchange materials: Seizing the caesium pp161 - 162

Abraham Clearfield


Public acceptance of the expansion of nuclear power may hinge on the safe disposal of nuclear waste. Ion exchangers that remove radioactive metals — such as caesium ions — from the waste could provide part of the answer, so a flexible-framework material that selectively grab them from solution is a step in the right direction.

Subject Categories: Inorganic chemistry | Materials chemistry

See also: Article by Ding & Kanatzidis

Supramolecular gels: Building bridges pp162 - 163

David K. Smith


Supramolecular gels, which rely on non-covalent interactions, are typically fragile. Now, hydrogels that possess remarkable mechanical strength combined with the ability to rapidly self-heal have been built through multiple non-covalent interactions.

Subject Categories: Materials chemistry | Supramolecular chemistry

Polymer synthesis: Facilitating functionality pp164 - 165

Steve Rimmer


Monomers that contain masked ketene groups provide new opportunities for facile crosslinking and post-synthetic modification of polymers in a wide variety of materials applications.

Subject Categories: Polymer chemistry | Synthesis

See also: Article by Leibfarth et al.

Isomerism: The same but different pp165 - 166

Thomas Bally


Electromerism is an unfamiliar concept to many chemists and refers to molecules that are not conventional isomers but instead differ in how the electrons are distributed across their structure. A novel example of such electromers has now been demonstrated.

Subject Categories: Organometallic chemistry | General chemistry



Organocatalytic cascade reactions as a new tool in total synthesis pp167 - 178

Christoph Grondal, Matthieu Jeanty & Dieter Enders


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The field of organocatalysis has grown rapidly in the past decade to become, along with metal catalysis and biocatalysis, a third pillar of asymmetric catalysis. Here, progress in the use of organocatalytic cascade reactions for total synthesis is reviewed. The elegance and efficiency of such cascades mean that they have emerged as a powerful tool in synthetic organic chemistry.

Subject Categories: Organic chemistry | Synthesis



Watching conformational- and photodynamics of single fluorescent proteins in solution pp179 - 186

Randall H. Goldsmith & W. E. Moerner


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A method for observing the photodynamics of single molecules, without having to immobilize them to a surface or confine them within vesicles, has been used to study the important photosynthetic antenna protein, allophycocyanin. Light-induced conformational changes and a complex relationship between fluorescence intensity and lifetime have been observed.

Subject Categories: Photochemistry | Physical chemistry

See also: News and Views by Dedecker & Hofkens

Selective incarceration of caesium ions by Venus flytrap action of a flexible framework sulfide pp187 - 191

Nan Ding & Mercouri G. Kanatzidis


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A perforated framework material of gallium antimony sulfide is able to selectively extract caesium ions from solution. After this capture, the holes close and prevent the ions leaching back out. This dynamic response could be used to remove caesium from nuclear waste.

Subject Categories: Inorganic chemistry | Materials chemistry

See also: News and Views by Clearfield

A palladium-catalysed enolate alkylation cascade for the formation of adjacent quaternary and tertiary stereocentres pp192 - 196

Jan Streuff, David E. White, Scott C. Virgil & Brian M. Stoltz


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The selective construction of multiple adjacent stereocentres is an important challenge for synthetic organic methodology, and only a handful of catalytic methods exist that can forge adjacent quaternary and tertiary stereocentres. Here, a palladium-catalysed multiple-bond-forming cascade leads to the construction of such systems in high yield, diastereomeric ratio and enantiomeric excess.

Subject Categories: Organic chemistry | Synthesis

Formation of mixed-phase particles during the freezing of polar stratospheric ice clouds pp197 - 201

Anatoli Bogdan, Mario J. Molina, Heikki Tenhu, Erwin Mayer & Thomas Loerting


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Chlorine-activation reactions on polar stratospheric cloud (PSC) particles are crucial to ozone depletion in the winter/spring polar stratosphere and their rates depend on the phase state of the PSC particle surface. Now experiments show that, on particle formation, a phase separation into pure ice with a residual solution coating takes place.

Subject Categories: Physical chemistry | Environmental chemistry

A concentric planar doubly π-aromatic B19 cluster pp202 - 206

Wei Huang, Alina P. Sergeeva, Hua-Jin Zhai, Boris B. Averkiev, Lai-Sheng Wang & Alexander I. Boldyrev


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A combined theoretical and experimental approach has been used to investigate the structure and bonding of an all-boron cluster (B19). Calculations suggest that the minimum energy structure is a near-planar one — in which a pentagonal B6 unit is encircled by a larger B13 ring — possessing two concentric aromatic π systems.

Subject Categories: Inorganic chemistry | Physical chemistry | Theoretical chemistry

A facile route to ketene-functionalized polymers for general materials applications pp207 - 212

Frank A. Leibfarth, Minhyuk Kang, Myungsoo Ham, Joohee Kim, Luis M. Campos, Nalini Gupta, Bongjin Moon & Craig J. Hawker


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The ability to rapidly functionalize polymers is vital for application development. Here, a method for the introduction of masked ketenes into monomers for both ring-opening metathesis and radical-type polymerizations is described. These ketenes — a group previously underexploited in polymer chemistry — allow both crosslinking and post-polymerization functionalization of the polymers.

Subject Categories: Materials chemistry | Polymer chemistry

See also: News and Views by Rimmer

Anisotropic oxygen diffusion at low temperature in perovskite-structure iron oxides pp213 - 217

Satoru Inoue, Masanori Kawai, Noriya Ichikawa, Hiroshi Kageyama, Werner Paulus & Yuichi Shimakawa


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The movement of oxygen ions through materials is important in electrolytes and separation membranes, but is rare at lower temperatures. Two different low-temperature diffusion pathways are revealed during the reduction process of CaFeO2.5 to CaFeO2. The two pathways are significantly different, resulting in anisotropy.

Subject Categories: Inorganic chemistry | Materials chemistry

Synthesis of a molecular trefoil knot by folding and closing on an octahedral coordination template pp218 - 222

Jun Guo, Paul C. Mayers, Gloria A. Breault & Christopher A. Hunter


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The synthesis of interlocked compounds such as catenanes and rotaxanes has undergone much development in recent years, but molecular knots are still relatively hard to make. It has now been shown that a linear bipyridine oligomer can fold around a single zinc-ion template to form a complex that can be cyclized to give a molecular trefoil knot.

Subject Categories: Organic chemistry | Supramolecular chemistry | Synthesis

See also: News and Views by Fenlon

Exploring local currents in molecular junctions pp223 - 228

Gemma C. Solomon, Carmen Herrmann, Thorsten Hansen, Vladimiro Mujica & Mark A. Ratner


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A methodology for describing local electronic transmission through bridging molecules between metallic electrodes is presented. Its application to simple alkane, phenyl and cross-conjugated systems highlights an unexpected number of cases whereby ‘through space’, rather than ‘through bond’ terms dominate and that interference effects coincide with the reversal of ring currents.

Subject Categories: Theoretical chemistry | Physical chemistry

Solution structure of a DNA double helix with consecutive metal-mediated base pairs pp229 - 234

Silke Johannsen, Nicole Megger, Dominik Böhme, Roland K. O. Sigel & Jens Müller


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The incorporation of non-natural base pairs into double-stranded DNA, especially those mediated by metal–ligand interactions, offers new opportunities for synthetic DNA materials. The structural implications of such modifications will help guide developments in this area, and a solution structure of a B-type DNA duplex containing consecutive metal-mediated base pairs has now been elucidated.

Subject Categories: Analytical chemistry | Inorganic chemistry | Supramolecular chemistry

Exceptional ammonia uptake by a covalent organic framework pp235 - 238

Christian J. Doonan, David J. Tranchemontagne, T. Grant Glover, Joseph R. Hunt & Omar M. Yaghi


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The uptake of ammonia by a covalent–organic framework (COF) containing a high density of Lewis-acidic boron sites has been found to be significantly greater than that exhibited by other state-of-the-art porous materials. The ammonia can be removed by heating under vacuum and the structural integrity of the COF is maintained during adsorption/desorption cycles.

Subject Categories: Materials chemistry | Organic chemistry



A biocompatible condensation reaction for controlled assembly of nanostructures in living cells p239

Gaolin Liang, Hongjun Ren & Jianghong Rao



In Your Element

A flourish of fluorine p240

Herbert W. Roesky


Herbert Roesky relates how the small, highly electronegative fluorine atom unveiled the chemical reactivity of noble gases and found many practical applications. but it can also render organic compounds highly toxic or pollutants.