Chemical Communications Blog

ISMSC: Cram Lehn Pedersen Prize awarded

13 Jul 2011

Professor Amar Flood delivered the inaugural Cram Lehn Pedersen Prize lecture at at the 6th International Symposium on Macrocyclic and Supramolecular Chemistry (6-ISMSC) in Brighton last week. The lecture, entitled ‘Binding and releasing anions with CH hydrogen-bonded receptors’, discussed his group’s efforts to regulate chloride concentrations in solution using aryl-triazole foldamers bearing azobenzene units. The foldamers can reversibly bind and liberate chloride depending on the wavelength of light shone on them.

The prize was sponsored by ChemComm and Dr Robert Eagling, ChemComm Editor, presented the certificate to Professor Flood.

: Professor Amar Flood (right) receives his award certificate from ChemComm Editor Dr Robert Eagling

You can read some of Professor Flood’s recent research in the recent supramolecular chemistry web theme issue:
Two levels of conformational pre-organization consolidate strong CH hydrogen bonds in chloride–triazolophane complexes
Yuran Hua, Raghunath O. Ramabhadran, Jonathan A. Karty, Krishnan Raghavachari and Amar H. Flood, Chem. Commun., 2011, 47, 5979-5981

Find out more about ISMSC in my conference blog.

And don’t forget – there is still time to submit your nomination for the 2012 Cram Lehn Pedersen prize. Deadline 31st July 2011. See the call for nominations for more details.

Comments Off on ISMSC: Cram Lehn Pedersen Prize awarded

Loudspeakers in your window

11 Jul 2011

By Emma Shiells, Development Editor.

Korean scientists have used graphene sheets to make a transparent and lightweight loudspeaker which, they say, can be attached to windows and computer screens.

Graphene, whose isolation led to the Nobel prize in physics for Andre Geim and Konstantin Novoselov, is a single layer of graphite. Owing to its remarkable mechanical and electronic properties, it is set to revolutionise modern technology and new uses for it are continuously being discovered. However, one of the big challenges is to fabricate large area films of graphene.

Now, Jyongsik Jang and coworkers from Seoul National University have used inkjet printing and vapour deposition to deposit graphene oxide onto poly(vinylidene fluoride) (PVDF), which is then reduced to create a graphene film. This demonstrates not only a new method for making controlled graphene films, but also a new use for the material: for making a thin transparent loudspeaker.

The acoustic actuator consists of a graphene-based transducer connected to the sound source and amplifier

The speaker system consists of a PVDF thin film sandwiched between two graphene electrodes. The speaker works because when an electrical current from the sound source is applied, the converse piezoelectric effect causes the PDVF film to distort, creating sound waves.

Such a system would be easy to install and usable anywhere where sound is needed, Jang explains. They could even eventually be used as noise cancelling devices by creating anti-noise waves (same amplitude but with inverted phase to the original sound).

To read more please visit the Chemistry World website, or download the original ChemComm communication.

Comments Off on Loudspeakers in your window

Recognition of T-containing DNA bulges with Macrocyclic Zinc complexes

11 Jul 2011

By Emma Shiells, Development Editor.

DNA bulges occur when one or more extra bases are added on one side of the DNA strain during the transcription process. These bases generally face either inwards or outwards with respect to the main helix. If we imagine DNA as a straight ladder, a bulge would be a half step that fails to reach the other side. DNA bulges, if not corrected after the transcription process, can often lead to mutations and to the rise of diseases and life threatening conditions. Particular DNA bulges are also relevant in the replication of HIV.

Due to the importance and biological significance of these structures, many studies have been conducted towards the development of molecules that specifically target and recognise these modifications. Molecules have been developed to selectively bind to bulges containing Guanine(G), Adenine(A) and aggregates of Cytosine/Thymine(C/T), but very few show high selectivity for T alone.

The group led by Janet R. Morrow, of the University of Buffalo focused on thymine, and developed a Zn(II) based macrocyclic complex that exhibits a higher than 100-fold specificity for T bulges. The complex is based on a modified cyclen backbone with a quinoline-containing pendant arm, which proved essential for the enhanced selectivity and binding abilities.

Another interesting feature emerging from the study is that when tested on oligonucleotides containing single-base bulges in the stem of a hairpin or a duplex structure, binding occurred without damage to the structure of the stem and only when T was in the bulge. Several other oligonucleotides with different bases in the bulge and with thymine in the hairpin stem (no bulge) were tested to further assess the selectivity of the complex, resulting in only one example of reduced binding when the T bulge has a cytosine on both sides.

NMR titrations were used to follow the binding process thanks to a clear change in the chemical shift of methylenic protons on the base after coordination.

To read the original ChemComm communication, please take a look at:-

Recognition of thymine in DNA bulges by a Zn(II) macrocyclic complex
Imee Marie A. del Mundo, Matthew A. Fountain and Janet R. Morrow
Chem. Commun., 2011, Advance Article

Posted on behalf of Dr. Giorgio De Faveri, Web Writer for Catalysis Science & Technology.

Comments Off on Recognition of T-containing DNA bulges with Macrocyclic Zinc complexes

Another successful year for the general chemistry journals

30 Jun 2011

By Emma Shiells, Development Editor.

ChemComm front cover with 2010 impact factor

ChemSocRev front cover with 2010 impact factor

Another year, another impact factor and the RSC general chemistry journals, Chem Soc Rev and Chem Comm, are still going strong. The 2010 impact factors were announced by ISI (Thomson Reuters) this week, which showed Chem Soc Rev increase by a whopping 32% to 26.583, and ChemComm continuing to do well at 5.787.

The Cambridge Editorial Office would like to thank everyone involved for their hard work and dedication to both journals over the years. In particular, we would like to thank all of our Associate Editors, Editorial and Advisory Board members, authors and referees, without whom none of this would have been possible.

With another successful year in the bag, I’m already looking forward to what the future brings…

If you are interested in how the RSC performed overall then please visit the RSC publishing blog post for the full round up.

Comments Off on Another successful year for the general chemistry journals

Organocatalysis – announcing a joint ChemComm–OBC web theme

29 Jun 2011

By Joanne Thomson.

We are delighted to announce a forthcoming ChemComm–Organic & Biomolecular Chemistry (OBC) web themed issue:

Organocatalysis

Guest editors: Keiji Maruoka (Kyoto University), Hisashi Yamamoto (University of Chicago), Liu-Zhu Gong (University of Science and Technology of China) and Benjamin List (Max-Planck-Institut für Kohlenforschung)

Submission deadline: 29th February 2012

We are now inviting submissions for this web theme, which will be a celebration of current achievements and future perspectives in this exciting field of research.

ChemComm and OBC are both welcoming urgent communications; OBC also welcomes full papers. Please feel free to submit to either or both journals.

All manuscripts will undergo strict peer review and should be very important and conceptually significant in accord with the ChemComm and OBC mandates.

Publication of the peer-reviewed articles will occur without delay to ensure the timely dissemination of the work. The articles will then be assembled on the RSC Publishing Platform as a web-based thematic issue, to permit readers to consult and download individual contributions from the entire series.

Communications for this web theme can be submitted anytime from now until 29th February using ChemComm‘s and OBC‘s web submission system. Please add the phrase ‘organocatalysis web theme‘ in the comments to the editor field.

Comments Off on Organocatalysis – announcing a joint ChemComm–OBC web theme

Superior catalytic performance for copper zeolites

28 Jun 2011

By Emma Shiells, Development Editor.

Scientists in China have designed a low-cost copper-amine complex and used it as a template for the one-pot synthesis of a zeolite that exhibits excellent catalytic performance.

One-pot synthesis of copper zeolite

Feng-Shou Xiao from Zhejiang University and co-workers from Jilin and Beijing Normal Universities, worked together on rationally designing the copper zeolite (Cu-ZJM-1) with changeable Si/Al ratios. The resulting Cu-ZJM-1 has much higher copper content and a better dispersion of copper cations compared to other zeolites reported in the literature. It exhibits excellent properties when it comes to the selective catalytic reduction of the environmentally harmful gas nitrogen oxide (NOx), by ammonia.

Download this ChemComm communication, which will be free to access until the 15th July 2011.

Comments Off on Superior catalytic performance for copper zeolites

Iron carbonyl catalyst leads the way

28 Jun 2011

By Emma Shiells, Development Editor.

A new iron carbonyl catalyst efficiently reduces amides using lower catalyst concerntrations, quicker reaction times and lower reaction temperatures, say scientists in Japan.

Iron carbonyl catalyst reduces various carboxamides using hydrosilane

Hideo Nagashima and colleagues from Kyushu University have reported a new heptanuclear iron carbonyl catalyst that can reduce various carboxamides using hydrosilane, 1,2-bis(dimethylsilyl)benzene. This is an important development as the catalyst actually shortens the reaction times, even at lower catalyst concentrations and at lower temperatures, when compared with other reported iron-catalysed hydrosilane reductions.

Fancy reading more? Then download the ChemComm communication, which will be free to access until the 15th July 2011.

Comments Off on Iron carbonyl catalyst leads the way

Tetrafluorocyclohexane: a novel polar motif

28 Jun 2011

By Joanne Thomson.

The cyclohexane motif is among the most common in organic chemistry but selectively fluorinated versions are rare. The high polarity of C–F bonds can influence the conformation and reactivity of molecules, making fluorinated molecules high on the target list of many chemists, including David O’Hagan at the University of St Andrews, UK.

His team have managed to make 1,2,3,4-tetrafluorocyclohexane, the first example of a cyclohexane with more than two vicinal fluorine atoms. The all syn stereochemistry forces two of the C–F bonds into 1,3-diaxial orientations. This diaxial interaction makes the molecule polar, which O’Hagan suggests could make it a novel polar structural motif for organic materials.

Graphical abstract: Synthesis and structure of all-syn-1,2,3,4-tetrafluorocyclohexane

Find out more: download O’Hagan’s ChemComm communication for free until 28th July.

Also of interest: Fluorine chemistry web theme

Comments Off on Tetrafluorocyclohexane: a novel polar motif

Quantum dots selectively label endoplasmic reticulum

27 Jun 2011

By Joanne Thomson.

Graphical abstract: Selective labeling of the endoplasmic reticulum in live cells with silicon quantum dots Scientists are a step closer to understanding how an important cell organelle works, which could lead to new insight into disease such as diabetes and Alzheimer’s disease.

The endoplasmic reticulum (ER) plays a critical role in protein synthesis and transport. Its malfunction can lead to serious diseases so it is important to be able to observe how it works.

Yukio Yamaguchi and colleagues at the University of Tokyo, Japan, have managed to selectively label the ER in live cells using quantum dots (QDs). Although organic dyes have previously been used for this purpose, Yamaguchi’s QDs are less toxic and more photostable.

The QDs’ photoluminescence enabled the team to view the ER using a confocal microscope, making them a powerful tool for long-term real-time observation of the ER, Yamaguchi says.

Find out more by downloading the communication.

Comments Off on Quantum dots selectively label endoplasmic reticulum

Metal organic frameworks for hydrogen storage

23 Jun 2011

By Joanne Thomson.

Hydrogen is seen by many as the energy to fuel the future of the automotive industry. But its low polluting profile and high energy efficiency are currently overshadowed by the technical difficulties in developing safe and efficient storage strategies for mobile applications.

Alternatives to the common high pressure tanks have been looked for over the years and some promising results came from the use of metal hydrides, formic acid, carbon nanotubes, metal organic frameworks (MOFs) as storage supports.

MOF research for hydrogen storage is a young field, established in the early 2000s when reports of the application of these porous materials started to appear in journals such as Science (Science, 2003, 300 (5622), 1127-1129 DOI: 10.1126/science.1083440). After the first proofs of concept, research has moved on increasing the hydrogen absorption capabilities of these materials by screening different metals, organic linkers and fabrication techniques.

The group lead by Champness and Schröder at the University of Nottingham, not new to the field (Angew. Chem. Int. Ed. 2006, 45, 7358 –7364, DOI: 10.1002/anie.200601991; Nature Chemistry 1, 487 – 493 (2009), DOI:10.1038/nchem.333), has recently focused on the development of two new scandium(III)-based MOFs that exhibit promising hydrogen absorption qualities. The novel materials, based on the general formula [M₂(μ₂-OH)(OCR)₄)], were characterised and their performance as storage supports tested.

Graphical abstract: Highly porous and robust scandium-based metal–organic frameworks for hydrogen storage The novel MOFs, NOTT-400 and NOTT-401, share the same metal-based fragment as building block and differ from each other by the organic linker employed (H₄BPTC and H₂TDA). They retained high crystallinity up to 500 °C and 350 °C respectively and were successfully reacted with acetone and degassed to afford the fully desolvated material ready for use.

The hydrogen absorption capabilities were tested at 77 and 87 K at hydrogen pressures ranging up to 20 bar with a maximum absorption of 4.44 wt% at 20 bar for NOTT-401. The absorption kinetics showed a very fast intake, reaching equilibrium in about 3 minutes, and good reversibility. No hysteresis was observed.

For the original communication see:
Highly porous and robust scandium-based metal–organic frameworks for hydrogen storage
Ilich A. Ibarra, Sihai Yang, Xiang Lin, Alexander J. Blake, Pierre J. Rizkallah, Harriott Nowell, David R. Allan, Neil R. Champness, Peter Hubberstey and Martin Schröder
Chem. Commun., 2011, DOI: 10.1039/C1CC11168J

Posted on behalf of Dr. Giorgio De Faveri, Web Writer for Catalysis Science & Technology.

Comments Off on Metal organic frameworks for hydrogen storage

Chemical Communications Blog

ISMSC: Cram Lehn Pedersen Prize awarded

Loudspeakers in your window

Recognition of T-containing DNA bulges with Macrocyclic Zinc complexes

Another successful year for the general chemistry journals

Organocatalysis – announcing a joint ChemComm–OBC web theme

Superior catalytic performance for copper zeolites

Iron carbonyl catalyst leads the way

Tetrafluorocyclohexane: a novel polar motif

Quantum dots selectively label endoplasmic reticulum

Metal organic frameworks for hydrogen storage

Links

Categories

Archives

Meta