Archive for December, 2010

Doubt cast on X-ray structure of trapped reactive species

Immobilisation inside a cavity can be a very effective strategy for stabilising reactive species. In fact, earlier this year, a team of French scientists claimed in Science1 to have used this technique to elucidate the solid state crystal structure of 1,3-dimethylcyclobutadiene trapped along with carbon dioxide inside an optimised host.

But, says Henry Rzepa from Imperial College London, UK, this claim should be treated with caution as his calculations suggest that the Science report is incorrect.

Based on his quantum chemical modelling studies, Rzepa proposes that reported crystal structure in fact is not that of 1,3-dimethylcyclobutadiene and carbon dioxide, but more probably that of the precursor used to attempt to generate the pair.

Graphical abstract: Can 1,3-dimethylcyclobutadiene and carbon dioxide co-exist inside a supramolecular cavity?

Find out more about this controversial issue in Rzepa’s ChemComm communication (free to access until 25th January 2011) and let us know what you think by leaving your comments below.

For further discussion, see Crystallographic Confusion in Chemistry Views magazine and Henry Rzepa’s blog.

1. Y.-M. Legrand, A. van der Lee, M. Barboiu, Science 2010, 329, 299-302

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Stimuli responsive DNA walking device

A pH responsive DNA walker has been designed by scientists in China.

Jingsong Ren and colleagues from the Chinese Academy of Sciences, have shown that the walker can reversibly transport specific molecules along an assembled track under environmental stimuli.

 

The team believe that this work is an important step in obtaining artificial nanomotors with precise motion control and will be highly beneficial for future applications and complex operations in diverse areas ranging from drug delivery to nanoscale assembly or patterning.

 

 

Interested in finding out more? Then download the communication today, published in ChemComm, it will be free to access until the 17th January 2011.

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Transporting salt across membranes

A dual host approach for co-transporting potassium chloride has been shown to be possible in lipid bilayers, using fluorescence-based transport assays.

Phil Gale and his team from Southampton University (and a collaboration with Kansai University) have shown that the addition of both a cationophore and anionophore can result in a significantly enhanced rate of anion transport through a lipid bilayer membrane.

 

To find out more, download the communication today, which will be free to access until the 17th January 2011. This communication is also part of the ‘Supramolecular Chemistry’ online collection, where Phil Gale (as well as Jonathan Sessler and Jonathan Steed) are guest editors for this web themed issue. 

 

 

 

If you enjoyed reading the ‘Hot’ communication above, you might also be interested in reading Phil Gale’s recent Highlight on “Anion receptor chemistry” (Chem. Commun., 2011, 47, 82-86).

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Catalysis and Sensing for Health Symposium

From the 31st of January to the 2nd February 2011 at The University of Bath, University Hall.

CASH will be hosting a civic reception at the Roman Baths on the 1st February (from 7pm onwards) that will be free to all delegates.

 

Catalysis and Sensing for Health (CASH) Symposium is free for delegates from academic and charitable organisations.

Delegates from Industry are requested to contribute a daily registration fee of £40 for a single day or £60 for the whole conference.

For further information on the symposium and/or how to register for the event, then please visit the CASH website.

ChemComm, Chemical Science and Chem Soc Rev Editor, Robert Eagling, will be attending this event so if you would like to arrange a meeting with Robert, please email him at the Editorial Office.

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Frozen assets in biobanks

Scientists from Sweden have devised a technique that extracts both DNA and RNA from frozen tissue in a bid to improve large-scale extractions from samples stored in biobanks, which could aid cancer research.

Tobias Sjöblom and colleagues from Uppsala University used magnetic silica beads to target and extract DNA and RNA from tissue samples. Because DNA competes with RNA to attach to the beads, the DNA can be recovered first. ‘The technology fulfils an unmet need, so has a huge potential impact on tissue biobanking,’ says Lucy Mathot from Sjöblom’s team.

High quality DNA and RNA preparations are necessary to study genes responsible for cancer and to identify which cancer medication to use. Researchers prefer to carry out analyses using tissues frozen from fresh because the fragments they can get from these samples are longer and better preserved than with alternative methods. Current column-based techniques for the serial extraction of DNA and RNA are labour-intensive so are not suitable for large scale applications and the automation needs of cancer biobanks.

Reaction sequence

Tissue samples are broken down, magnetic silica beads are added, the beads attach to DNA and RNA and are removed with a magnet

Sjöblom’s team broke down the tissue samples by grinding them with a chaotropic salt solution, which helps to break down the DNA and RNA, and then added the magnetic silica beads. When the beads attached to the DNA, they were able to recover the samples with a magnet. Then they captured the remaining RNA in the same way.

Bert Vogelstein, a cancer researcher at the Johns Hopkins University School of Medicine in the US says: ‘The technique looks like it will be quite useful for preparing precious samples for next-generation sequencing analysis.’

In the future, the team plans to implement the procedure on a robotic platform to enable parallel sample processing.

Jennifer Newton

Interested? Read Sjöblom’s ChemComm communication.

Could your work be an asset to ChemComm? Submit today and make an impact.

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Now available – new article templates

We have introduced slightly revised templates for all our article types. This means that the citation information will be much more visible to readers, both online and in print, so should facilitate wider readership of your work.

Make sure you use the latest templates when submitting your next article.

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Hot article round up for November

Whilst most of us are shaking snow from our coats and wearing extra layers in a bid to keep warm this winter, here at the ChemComm Editorial Office we’ve had several hot articles to keep us nice and toasty.

 

From nonporous to nanoporous
Scientists in the US have discovered that a well-known organic host, tris-o-phenylenedioxycyclotriphosphazene,
exists in two polymorphic guest-free forms; a thermodynamic nonporous high-density phase and the kinetic nanoporous low-density phase. To find out more, read the communication published by Jerry Atwood, Praveen Thallapally and their colleagues.

McMurry coupling
Hiroko Yamada and colleagues have made a metal-free and meso-free triphyrin compound via an intramolecular McMurry coupling reaction and used the ligand to form manganese and rhenium complexes. Read more in their communication.

Smart behaviour
Selective adsorption of carbon nanotubes (CNTs) onto patterned gold surfaces has been achieved by scientists in Belgium. Pascal Damman and Philippe Dubois have shown in their communication that pH-induced switching can occur, enabling both controlled positioning and release of CNTs, opening up future development opportunities for CNTs-containing sensing devices

Water-holding MOF
There is much research activity using metal organic frameworks (MOFs) as hosts to a variety of guest molecules. Richard Walton and colleagues have now shown that a flexible MOF, once immersed in water at room temperature, can form a crystalline hydrate and hold the water as a hydrogen-bonded tube. To see this clever research for yourself why not take a closer look at their communication?

Photogenerated holes
Transient absorption spectroscopy has been used to monitor the yield and decay dynamics of photogenerated holes in nanocrystalline hematite photoanodes. To find out what happens in the presence and absence of a positive applied bias you will need to read James Durrant and Michael Gr
ätzel’s communication.

First replication NAND gate
In this communication, Gonen Ashkenasy and colleagues demonstrate the first peptide-based replication system that can be activated by shining light as well as being followed by fluorescence measurements.

Tailor-made mimicry
Thorsten Glaser and his team have designed a new dinucleating ligand system to mimic high-valent oxidation states of oxygen-dependent diiron enzymes. Read more on what they discovered in their communication.

Saccharide chemosensor
Gaku Fukuhara and Yoshihisa Inoue have synthesised a chromophore-modified saccharide chemosensor that can discriminate tetrasaccharide acarbose from 24 different mono-, di-, tri-, and tetrasaccharides. The sensors preferential selectivity for acarbose is pharmaceutically important as it is a drug used to treat diabetes and obesity. To read more, why not download the communication?

Let us know what you think of these articles by blogging some comments below. And if you have your own hot research, then submit to ChemComm today.

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Printing on bioactive paper

An enzyme printing process that prints the product of an enzyme-catalysed reaction, but not the enzyme molecule itself, has been designed by scientists in Australia to produce bioactive paper.

Taking their inspiration from traditional printing methods such as ink jet and thermal contact printing, Wei Shen and colleagues from Monash University, Australia, have used relief and planographic printing methods to print the product of a reaction catalysed by an enzyme, in this case horseradish peroxidise (HRP)…….

Fancy reading more? Then why not read the full story online in Chemistry World. You can also download the article, which has been published in ChemComm:-

Printing enzymatic reactions
Junfei Tian and Wei Shen, Chem. Commun., 2011
DOI: 10.1039/c0cc03369c

 

 

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Ionic liquid could be used as rocket fuel

A hydrazine-based ionic liquid could be used as rocket fuel, say US scientists.

The combustibility of ionic liquids, a hazard for most applications, has inspired researchers to consider them as possible propellants in rocket fuels. Robin Rogers and his colleagues from The University of Alabama in Tuscaloosa and C3 Propulsion in Huntsville have found that an ionic liquid based on one of the most widely used rocket fuel propellants, hydrazine, ignited on contact with a catalyst, without the need for an oxidant or an ignition source.

The team studied the behaviour of nitrate salts of 2-hydroxyethylhydrazinium upon addition of various catalysts. It was found that in the presence of one particular solid catalyst, Ir-alumina (known as Shell 405), and at temperatures above only 100 °C, the salts ignited, producing smoke and gas.

Addition of 2-hydroxyethylhydrazinium dinitrate to the solid catalyst Shell 405, followed by smoke, flame and residual catalyst

Rogers explains that the impetus for the research was increased safety: ‘we wanted to see if we could take a hydrazine-like molecule, which is volatile, turn it into a non-volatile salt and yet still have the same reactivity that the hydrazine did. We were pretty excited because it worked.’

In addition to decreasing vapour toxicity by replacing hydrazine with an ionic liquid, this material could lead to safer, more efficient, forms of rocket fuel since ignition could occur simply by running the ionic liquid over a catalyst bed, eliminating the need for stabilisers or an additional liquid oxidant.

‘Clearly, this is not only a safer way of propellant ignition, it is also more effective as it allows for low temperature combustion,’ says Christopher Hardacre, an expert in ionic liquids and catalysis from Queen’s University Belfast in Northern Ireland. Hardacre adds that the low volatility associated with ionic liquids as well as the low cost of the materials makes this propellant system even more attractive for various applications.

The work is still in its infancy and the next step will be to optimise the material for specific applications. ‘We need the real rocket scientists out there to weigh in and tell us what needs to be improved or to find better molecules or better salts,’ says Rogers.

Patricia Pantos

For more information, download Rogers’ ChemComm communication.

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Emerging Investigators issue now published online!

Finally, the wait is over - ChemComm issue 1 has arrived and it does not fail to disappoint! It is bursting at the seams, filled with some truly outstanding Feature Articles and Communications from emerging scientists from across the globe, all of whom are in the early stages of their independent careers.

So why not take a look at issue 1 today? It is available to view online and all the articles will be free to access until the end of 2011. If you would like to be considered for next year’s issue (2012) then please email the ChemComm Editorial Office expressing your interest.

We are also pleased to announce that this ’Emerging Investigators issue’ has also been recognised as an official activity for celebrating the International Year of Chemistry (IYC) during 2011. Why not take a look at the IYC website and keep up-to-date on what else is happening throughout 2011 to celebrate the achievements of chemistry and its contributions to the well-being of humankind.

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