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‘The next generation of SEC/GPC Analysis’ free webinar on 30 April 2013– register now!

17 Apr 2013

Join Chemistry World and Waters for this free webinar on ‘The Next Generation of SEC/GPC Analysis’ in order to…

Identify the requirements for an advanced chromatographic system to meet the needs for determination of molecular weight distributions

Understand the benefits of a complete system approach to molecular weight characterization

See how the new paradigm in molecular size characterization will reduce test cycle time and consumption of operating chemicals while providing improved test precision with statistically enhanced data sets

See where the innovative separation approach can allow for a deeper understanding of polymeric properties and their variation

Register today at http://rsc.li/waters-acquity

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Metal organic frameworks for moisture-triggered fragrance release

11 Apr 2013

The controlled release of fragrance molecules is of great interest in the development of fragranced products such as deodorants, as the volatility of the fragrance molecules can reduce the action of the product over time. In this HOT ChemComm article, Jing Li and her group at Rutgers University, New Jersey have joined forces with researchers from Colgate-Palmolive Company to investigate using metal organic frameworks (MOFs) to take up and release fragrances in response to external stimuli.

frangrance release by MOFs

MOFs are a class of porous materials that are receiving a significant amount of research interest. In particular, their ability to take up and store small molecules makes them an exciting prospect for storing gases, such as hydrogen, for catalysis and for drug delivery.

In this study, researchers examined the ability of some zinc based MOFs containing hydrophobic channels to take up and release the fragrances ethyl butyrate and D-limonene. They found that the release of these fragrances could be triggered by moisture.

Importantly, both the hydrophilic ethyl butyrate and the hydrophobic D-limonene could be stored and released in this way, whereas leading encapsulation technologies based on modified starch are generally only useful for storing hydrophobic fragrances. MOFs could therefore well find commercial applications for storing a wide range of fragrances.

Read this ‘HOT’ ChemComm article today!

Encapsulated recyclable porous materials: an effective moisture-triggered fragrance release system
John Vaughn, Haohan Wu, Bisera Efremovska, David H. Olson, Jairajh Mattai, Claudio Oritz, Allen Puchalski, Jing Li and Long Pan
Chem. Commun., 2013, Advance Article
DOI: 10.1039/C3CC41236A

Cally Haynes is a guest web-writer for ChemComm. She is currently a post doctoral researcher at the University of Southampton, and her research interests include the supramolecular chemistry of anions. When not in the laboratory, she likes travelling and watching football.

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Nitrogen-containing graphene-like structures: Theory and experiment combine to reveal active sites

09 Apr 2013

There is significant interest in nitrogen-containing electrocatalysts, driven by the need to find cost-effective and efficient material solutions for replacing platinum in polymer electrolyte membrane fuel cells. However, the active sites of non-platinum group metal, oxygen reduction reaction electrocatalysts have been contentious for over 50 years.

Fortunately researchers are agreed that Metal(Me)-N_x centres may serve as possible active sites but whether it is Me-N₂ or Me-N₄ remains unresolved. X-ray Photoelectron Spectroscopy (XPS) would be the ideal technique to answer this question if it didn’t rely on the use of reference spectra; none exist for the Me-N₂ species which makes it less than ideal.

Fitting of DFT calculated curves to experimental results.

Kateryna Artyushkova, Plamen Atanassov and their team have overcome this problem by using density functional theory (DFT) to calculate the binding energy shifts of the species. Calculating the binding energy shifts, rather than just the binding energies, allows the team to overcome the challenges associated with DFT calculations including; treatment of the core electrons and the poorly screened Coulomb potential near the nucleus.

Once validated, the DFT output can be used as input for XPS curve fitting. This has revealed rearrangement around Cobalt-N_x centres in an oxidizing atmosphere and supports the understanding of these catalysts as vacancy-and-substitution defects in a graphene-like matrix.

This work demonstrates the synergy between experiment and theory which allows critical information to be extracted that might otherwise remain hidden.

For more, read this ChemComm article in full:

Density functional theory calculations of XPS binding energy shift for nitrogen-containing graphene-like structures
K. Artyushkova, B. Kiefer, B. Halevi, A. Knop-Gericke, R. Schlogl and P. Atanassov
Chem. Commun., 2013, 49, 2539-2541
DOI: 10.1039/C3CC40324F

Iain Larmour is a guest web-writer for ChemComm. He has researched a wide variety of topics during his years in the lab including nanostructured surfaces for water repellency and developing nanoparticle systems for bioanalysis by surface enhanced optical spectroscopies. He currently works in science management with a focus on responses to climate change. In his spare time he enjoys reading and photography.

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X-ray nanoscopy of cobalt Fischer–Tropsch catalysts at work

08 Apr 2013

Cobalt Fischer–Tropsch catalysts have been investigated in both 2-D and 3-D, by scientists in the Netherlands and the US, using in situ hard X-ray transmission X-ray microscopy (TXM). The Fischer–Tropsch process is an important step in the production of liquid fuels from natural gas, biomass or coal.

Tomographic elemental mapping revealed the 3-D distribution of cobalt over the catalyst particles showing that cobalt is heterogeneously concentrated in the centre of the catalyst particles. 2-D chemical mapping allowed them to follow the chemical composition of the catalyst particles under reaction conditions.

This is the first time that this particular catalyst has been observed at the single particle level under reaction conditions, allowing the team to get a true picture of the deactivation of the catalyst which will provide information to help improve the catalyst’s productivity.

‘HOT’ Communication – read for free today:

X-ray Nanoscopy of Cobalt Fischer-Tropsch Catalysts at Work
Korneel Cats , Inés González-Jiménez , Yijin Liu , Johanna Nelson , Douglas van Campen , Florian Meirer , Ad M.J. van der Eerden , Frank M F de Groot , Joy C. Andrews and Bert Weckhuysen
Chem. Commun., 2013, DOI: 10.1039/C3CC00160A

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‘Breathprint’ analysis as a real-time, non-invasive diagnostic tool

05 Apr 2013

Scientists, led by Renato Zenobi of the Swiss Federal Institute of Technology (ETH) in Zurich, have been investigating metabolites in exhaled breath, showing that each person’s breath holds a unique, characteristic molecular ‘breathprint,’ as recently featured on the BBC website. This means that high-precision chemical analysis of a patient’s breath can potentially provide an instant, pain-free and non-invasive medical diagnosis, and may even provide an early warning for healthy persons at risk for certain diseases. In the future, it may also be used to calculate safe dosages of anaesthesia tailored to each patient’s metabolism and tolerance, or as a fast and convenient doping check for athletes.

Using mass spectrometry, Zenobi and his team regularly measured and analysed the exhaled breath of eleven volunteers for eleven days, finding that each individual’s metabolic ‘breathprint’ showed a unique core pattern and remained stable enough to be useful for medical purposes. Their mass spectra of exhaled breath have shown peaks or signals representing around a hundred compounds, most of which they are just beginning to identify and assign.

Their findings represent a significant step towards ‘personalised medicine,’ and show great potential for other applications, such as in forensics or metabolomics.

Zenobi and his co-workers first published their early work in chemical breath analysis in a 2011 ChemComm article, in which they used their novel method to identify valproic acid, a medication for epilepsy, in exhaled breath.

C1CC10343A

Read the ChemComm article where it all began!

Real-time, in vivo monitoring and pharmacokinetics of valproic acid via a novel biomarker in exhaled breath
Gerardo Gamez, Liang Zhu, Andreas Disko, Huanwen Chen, Vladimir Azov, Konstantin Chingin, Günter Krämer and Renato Zenobi
Chem. Commun., 2011, 47, 4884-4886
DOI: 10.1039/C1CC10343A

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Gold nanoparticles reveal fingerprints

03 Apr 2013

Gold nanoparticles capped with mercaptocarboxylic acids, followed by silver precipitation, have been used to develop latent fingerprints on paper as high quality negative images. Scientists writing in the journal ChemComm say that the effect stems from hydrogen bonding between the carboxylic group and the paper cellulose.

Recovering fingerprints from paper is a common task for forensic scientists, but often the developed marks are faint. A common approach, therefore, is to use a developing agent that sticks to the clean paper substrate, rather than the fingerprint itself, yielding a reversed image.

The technique described in this study is much less affected by sweat composition, and could improve the yield of latent fingerprints.

Read the ‘HOT’ ChemComm article today for free:

A novel approach to fingerprint visualization on paper using nanotechnology: reversing the appearance by tailoring the gold nanoparticles’ capping ligands
Sanaa Shenawi , Nimer Jaber , Joseph Almog and Daniel Mandler
Chem. Commun., 2013, DOI: 10.1039/C3CC41610K

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Tomoki Ogoshi wins Cram Lehn Pedersen Prize 2013

28 Mar 2013

Congratulations to Professor Tomoki Ogoshi (Kanazawa University, Japan), the winner of the 2013 Cram Lehn Pedersen Prize.

The annual prize, sponsored by ChemComm and named in honour of the winners of the 1987 Nobel Prize in Chemistry, recognises significant, original and independent work by emerging investigators in supramolecular chemistry.

This year the prize is awarded to Professor Ogoshi for his pioneering work in macrocyclic and supramolecular chemistry and, in particular, for his groundbreaking research on pillar[5]arenes, a new class of macrocyclic compounds. “I’m really honoured to receive the 2013 Cram Lehn Pedersen Prize,” says Professor Ogoshi. “Cram, Lehn and Pedersen were great pioneers in the synthesis of macrocyclic hosts, and thus receiving this prize is also a great honour for pillararene chemistry. I hope this will someday place pillararenes alongside other well-known macrocyclic hosts.”

Professor Ogoshi will receive £2,000 and will present his award lecture at the 8th International Symposium on Macrocyclic and Supramolecular Chemistry (8-ISMSC) in Crystal City, Virginia, USA from 7-11 July 2013. He will also speak at other events during the year– keep an eye on this blog for more details.

“With the introduction of a new class of macrocycles, the pillararenes, Professor Ogoshi has started another area of host-guest molecules,” says Professor Roger Harrison, Associate Professor at Brigham Young University and Secretary of the ISMSC International Scientific Committee. He adds, “The over 90 publications on these molecules since they were introduced in 2008, show the fascination and possibilities these molecules afford. Professor Ogoshi’s introduction of these new molecules, along with his insights, creativity, and persistence make him one of the most exciting and up-and-coming supramolecular chemists to follow. I congratulate Prof. Ogoshi on receiving this award and look forward to seeing more of his discoveries.”

Pillararene structure

“Ogoshi has created a new class of easy-to-make macrocycles, pillar[5]arenes, with a novel cross section of properties,” says Professor Amar Flood (Indiana University), a member of the ISMSC International Committee and 2011 Cram Lehn Pedersen Prize winner. “Ogoshi has highlighted the properties and features of pillararenes in a series of papers and we are now seeing many others in the field of supramolecular chemistry moving forwards with these compounds in their own research endeavors.”

Last year’s prize was awarded to Dr Jonathan Nitschke (University of Cambridge).

Early bird registration for 8-ISMSC closes on 15 April 2013, so do hurry and register online. You can listen to Professor Ogoshi’s lecture, get to meet a mix of established and younger researchers in supramolecular and macrocyclic chemistry, and you may even submit an abstract to present a short talk or a poster to showcase your work. ChemComm‘s own brilliant and dynamic Deputy Editor Jane Hordern will be at the symposium – let us know if you’ll be there, too.

Find out more about Professor Ogoshi’s innovative research by reading his recent articles in Chemical Science and in ChemComm:

Supramolecular polymers with alternating pillar[5]arene and pillar[6]arene units from a highly selective multiple host–guest complexation system and monofunctionalized pillar[6]arene
Tomoki Ogoshi, Hitoshi Kayama, Daiki Yamafuji, Takamichi Aoki and Tada-aki Yamagishi
Chem. Sci., 2012, 3, 3221-3226

Thermally responsive shuttling behavior of a pillar[6]arene-based [2]rotaxane
Tomoki Ogoshi, Daiki Yamafuji, Takamichi Aoki and Tada-aki Yamagishi
Chem. Commun., 2012, 48, 6842-6844

Ionic liquid pillar[5]arene: its ionic conductivity and solvent-free complexation with a guest
Tomoki Ogoshi, Naosuke Ueshima, Tada-aki Yamagishi, Yoshiyuki Toyota and Noriyoshi Matsumi
Chem. Commun., 2012, 48, 3536-3538

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Porous organic polymers filter toxins from the air

25 Mar 2013

In a search for the next generation of filtration materials, for use in devices such as gas masks, a group of US scientists has synthesised a series of porous organic polymers (POPs) bearing metal-catecholate groups. By changing the molecular building blocks the researchers were able to tailor the materials to hydrogen bond to, and consequently remove, different toxins, such as ammonia.

POPs are very similar in nature to metal-organic frameworks (MOFs) but do not suffer from such instability, particularly towards water, making them ideal for use as filters in real-word environments.

Read this ‘HOT’ Communication now:

Removal of airborne toxic chemicals by porous organic polymers containing metal–catecholates
Mitchell H. Weston , Gregory W. Peterson , Matthew A. Browe , Paulette Jones , Omar K. Farha , Joseph T. Hupp and SonBinh T. Nguyen
Chem. Commun., 2013,49, 2995-2997

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Making Bispirin: A new drug to fight both indigestion and pain

25 Mar 2013

Until now, drugs which fight gastrointestinal infections and those which treat acute inflammation have been found to interfere with each other. For instance, people infected with the Helicobacter pylori bacterium have needed to deal with the additional risk of gastrointestinal bleeding associated with the use of aspirin and other inflammatory drugs.

Australian research chemists, led by Philip C. Andrews of Monash University, have designed a new drug which treats gastrointestinal infections and acute inflammation at the same time. They have successfully synthesized bispirin, a bismuth acetylsalicylate complex which combines the effectiveness of bismuth carboxylate compounds as anti-infection agents with that of acetylsalicylic acid (aspirin) as an anti-inflammatory drug. Their initial tests have shown that bispirin’s antibacterial effects are comparable or better than those of current bismuth drugs, and investigations of bispirin’s anti-inflammatory activity are currently in progress.

Making Bispirin_graphical abstract

This journal article has also been recently featured on C&EN – read it here.

Read this ‘HOT’ ChemComm article in full:

Making Bispirin: synthesis, structure and activity against Helicobacter pylori of bismuth (III) acetylsalicylate

Philip C. Andrews, Victoria L. Blair, Richard L. Ferrero, Peter C. Junk and Ish Kumar

Chem. Commun., 2013, 49, 2870-2872

DOI: 10.1039/C3CC40645H

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Ready to order? Yes, I’ll have the extra cold superconducting penne, please…

21 Mar 2013

Written by guest web-writer Kevin Murnaghan.

In this highly original work, researchers from the Complex Functional Materials Group at the University of Bristol and the Superconductivity and Magnetism Group at the University of Warwick have used off-the-shelf, supermarket pasta as a sacrificial template for the production of a variety of superconducting wires, tubes and spirals. They have even made a superconducting ‘jolly roger’ skull and crossbones.

Here’s how: The pasta was pre-washed to remove impurities and then rehydrated in a solution containing a mixture of nitrates of yttrium, barium and copper. A slight excess of barium nitrate was used to make sure the desired superconducting material YBa₂Cu₂O_7-xphase (Y123) was attained. Via a calcination process the superconducting pasta shapes were produced, removing the organic material of the sacrificial template and neatly retaining the macroscopic shape of the template.

C3CC38271K_graphical abstract

‘Chemical black pepper and parmesan’ were provided by the use of silver nitrate in the process, which boosts electrical and structural properties. Without using this salt, structures formed are brittle, but with it, compressive strength of the shapes doubled in strength from 0.76 to 1.56 MPa. This helped counteract the effect of porosity formed from the outgassing of the sacrificial pasta during the calcination process.

Interestingly, the pasta had its own influence on the properties of the material. Starch-mediated reduction of Ag(I) to Ag(0) is the reason for the dark colour of the materials formed, and trace transition metals in the foodstuff were found to have an effect on electrical and superconducting properties.

Critical temperatures, T_c and current densities, J_c, in early samples were found to be low, relative to typical Y123 type superconductors when silver was not included in the synthesis, and were markedly improved when it was. Further improvements to the superconductivity of the spaghetti-based replicas were achieved via sintering and annealing. This work represents a highly cost-effective route to a range of superconducting materials with macroscopic architectures, compared with current state of the art processes such as CVD or PLD. Future work will focus, in part, on further densification of the product, and purity of the sacrificial template. Further fascinating information is provided in the electronic supplementary information. Buon appetito!

Read this ChemComm cover article today:

Designed 3D architectures of high-temperature superconductors

David C. Green, Martin R. Lees and Simon R. Hall

Chem. Commun., 2013,49, 2974-2976

DOI: 10.1039/C3CC38271K

Kevin Murnaghan is a guest web-writer for Chemical Communications. He is currently a Research Chemist in the Adhesive Technologies Business Sector of Henkel AG & Co. KGaA, based in Düsseldorf, Germany. His research interests focus primarily on enabling chemistries and technologies for next generation adhesives and surface treatments. Any views expressed here are his personal ones and not those of Henkel AG & Co. KGaA.

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