Chiral confusion

Scientists in Israel have shown that non-biological chiral crystals are much more abundant than previously thought and their findings could clear up a possible confusion over the term ‘chiral’.

‘Chiral’ describes an object whose mirror image cannot be superimposed, for example human hands are chiral. Chirality is important to understand and recognise, as the production of a chiral molecule can lead to both mirror images – or enantiomers – being produced, and these often have very different chemical properties. Chiral crystals selective for one enantiomer that could be used for separation or as catalysts are therefore highly sought.

Read the full article in Chemistry World

Link to journal article
On the abundance of chiral crystals
Chaim Dryzun and David Avnir
Chem. Commun., 2012, Advance Article, DOI: 10.1039/C2CC17727G


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Directing Biosynthesis III – final call for oral abstracts

LAST CALL FOR ORAL ABSTRACTS – DEADLINE THIS FRIDAY 11TH MAY 2012


Directing Biosynthesis III (DBIII), 19 – 21 September 2012, University of Nottingham, UK

Please don’t miss this last opportunity to submit an oral abstract now to be part of a high profile conference featuring contributions from the most active groups in the UK, Europe, the USA and Japan working in this rapidly developing area.

This meeting builds on the two previous extremely successful conferences in a subject area which remains highly topical. As significant opportunities exist for engineering biosynthetic pathways in bacteria, fungi and plants for the directed biosynthesis of new natural products with new and beneficial properties. We expect the programme this year to generate a high profile event that you will not want to miss.

Confirmed Invited speakers:

Ikuro Abe, University of Tokyo, Japan
Mervyn Bibb
, John Innes Centre, UK
David W. Christianson
, University of Pennsylvania, USA
Christian Hertweck
, Friedrich Schiller University Jena, Germany
Ben Liu
, The University of Texas at Austin, USA
Professor Jim Naismith
, University of St Andrews, UK
Joern Piel
, University of Bonn, Germany
Professor Chris Schofield
, University of Oxford, UK
David H Sherman
, University of Michigan, USA
Dr David R Spring
, University of Cambridge, UK
Tom Simpson
, FRS, University of Bristol, UK
Yi Tang
, UCLA, USA
NOW CONFIRMED – Craig Townsend
, John Hopkins University, USA

A special symposium will take place within the Directing Biosynthesis III programme, recognising the achievements of three 2011 RSC award winners. Each of the winners will give a keynote lecture within the symposium.

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Creating the first high-valent iron oxo phthalocyanines

Phthalocyanines are important industrial oxidation catalysts that are cheap and easy to make but their mechanism remains unclear. Now a team of French and Russian scientists have made and characterised a key intermediate in the catalytic cycle, previously postulated but never obtained.

Pavel Afanasiev and Alexander Sorokin from the CNRS-Université Lyon, France, and colleagues prepared and characterised the first high-valent iron oxo species on the phthalocyanine platform.

They treated tetra-tert-butylphthalocyanine iron chloride with m-chloroperbenzoic acid to give what they later proved to be an Fe(IV) oxo species. Isolation of such a reactive species is extremely challenging so the team characterised the reaction mixture in situ shortly after mixing the reagents. This approach also removed the possibility of the molecule undergoing further transformation en route to the X-ray diffraction facility or NMR spectrometer.

A DFT-optimized structure of the iron-oxo phthalocyanine complex
A DFT-optimized structure of the iron-oxo phthalocyanine complex

The team used at least eight different techniques – including mass spectrometry, UV-vis and EPR spectroscopy, density functional theory (DFT) and X-ray emission studies – in their incredibly thorough examination of the molecule, not only confirm its creation but to fully define many aspects of its electronic structure. These results provide a platform from which a better understanding of iron phthalocyanine catalysts can be developed. 

Keen to read more? Download this ChemComm article here or visit our web collection on Porphyrins & Phthalocyanines. 

Posted on behalf of Ruaraidh McIntosh, Chemical Communications web writer.

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Free ChemComm inorganic and supramolecular content

The ChemComm–RSC Prizes & Awards Symposium jointly organised with the Dalton Division takes place at the University of Oxford on 23rd May with the theme of inorganic and supramolecular chemistry.

This is ChemComm’s second UK-based symposium and to celebrate we’ve made some of our best content free to access for a limited period.

We hope you enjoy these articles – but don’t delay! Free access only runs until 30th May.

Germanium/phosphorus cage compounds with germanium in three different oxidation states
Stefan Almstätter, Gábor Balázs, Michael Bodensteiner and Manfred Scheer
Chem. Commun., 2011, 47, 9998-10000
DOI: 10.1039/C1CC13937A

Selective gas sorption in a [2+3] ‘propeller’ cage crystal
Shan Jiang, John Bacsa, Xiaofeng Wu, James T. A. Jones, Robert Dawson, Abbie Trewin, Dave J. Adams and Andrew I. Cooper
Chem. Commun., 2011, 47, 8919-8921
DOI: 10.1039/C1CC12460A

Reversible anion-templated self-assembly of [2+2] and [3+3] metallomacrocycles containing a new dicopper(I) motif
Emily F. V. Dry, Jack K. Clegg, Boris Breiner, Daniel E. Whitaker, Roman Stefak and Jonathan R. Nitschke
Chem. Commun., 2011, 47, 6021-6023
DOI: 10.1039/C1CC11206F

Cleavage of dinitrogen to yield a (t-BuPOCOP)molybdenum(IV) nitride
Travis J. Hebden, Richard R. Schrock, Michael K. Takase and Peter Müller
Chem. Commun., 2012, 48, 1851-1853
DOI: 10.1039/C2CC17634C

Metal-free diastereoselective catalytic hydrogenations of imines using B(C6F5)3
Zachariah M. Heiden and Douglas W. Stephan
Chem. Commun., 2011, 47, 5729-5731
DOI: 10.1039/C1CC10438A

Activation of phosphorus by group 14 elements in low oxidation states
Shabana Khan, Sakya S. Sen and Herbert W. Roesky
Chem. Commun., 2012, 48, 2169-2179
DOI: 10.1039/C2CC17449A

Twisted molecular magnets
Ross Inglis, Constantinos J. Milios, Leigh F. Jones, Stergios Piligkos and Euan K. Brechin
Chem. Commun., 2012, 48, 181-190
DOI: 10.1039/C1CC13558A

Luminescent metal complexes of d6, d8 and d10 transition metal centres
Vivian Wing-Wah Yam and Keith Man-Chung Wong
Chem. Commun., 2011, 47, 11579-11592
DOI: 10.1039/C1CC13767K

Uranium-mediated activation of small molecules
Polly L. Arnold
Chem. Commun., 2011, 47, 9005-9010
DOI: 10.1039/C1CC10834D

Also of interest: Take at look at our web themes on Supramolecular Chemistry and Frontiers in Molecular Main Group Chemistry.

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Optical chemosensors for sensing explosives

Peroxide-based explosives, such as triacetone triperoxide (TATP), have been increasingly used in criminal activities as they can be easily obtained and are highly sensitive (TATP has 88% the explosive equivalence of TNT). However, detecting TATP is not easy, despite its considerable vapour pressure at room temperature (7.87Pa), This is mainly because of its lack of nitro- or aromatic-groups, which could be revealed in UV absorbance or fluorescence spectra.

Here, researchers in China have demonstrated a new strategy to detect explosive peroxide vapor via deboronation reaction induced fluorescence quenching with good sensitivity (the detection limit of TATP vapour was estimated to be ~0.5ppm), selectivity and fast response.


 

Link to journal article
Highly Efficient Fluorescent Sensor of Explosive Peroxide Vapor via ZnO Nanorod Array Catalyzed Deboronation of Pyrenyl borate

C He et al
Chem. Commun.,
2012, DOI: 10.1039/c2cc31386c

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An interview with Richard Schrock

From a chemistry set to a Nobel Prize: the ChemComm chairman talks about his life and work.

Richard Schrock, Hon FRSC

Richard Schrock, Hon FRSC

What’s your earliest memory of chemistry?

When I was eight, my older brother Ted gave me a chemistry set. He was attracted to chemistry and thought I might be too. He was right.

Why did you decide to become an academic?

I wanted to change the world on the basis of what I thought was important to do, and I felt that I could only do that in an academic environment. I also wanted to mentor students, teach, lecture, and travel. The life of an academic is simply a more satisfying and broader life, in my opinion.

What are you currently working on in the lab?

A few years ago we discovered new olefin metathesis catalysts – they’re letting us do reactions that couldn’t have been done before, and that are virtually unique to molybdenum and tungsten catalysts, as opposed to ruthenium.

We’re also still trying to improve the catalytic reduction of dinitrogen to ammonia by molybdenum catalysts that we discovered about ten years ago.

Why did you accept the role as Chair of ChemComm?

I think it’s important for me to give back to chemistry some of what chemistry has given me – in the form of service. I’d like to see ChemComm become a journal that is uniformly excellent, and that attracts some of the best papers in competition with other premier journals today.

Even though ChemComm is largely devoted to communications, each article will require all the experimental details that one would expect to have access to, as supporting information, so people can verify and reproduce the work.

In which area in chemistry do you think the next world-shaking advances will be?

Well, predictions of the future are always difficult, and the answer will depend upon what your definition of chemistry is. I often point out that everything in which matter is transformed is chemistry, so that takes care of the latter problem.

If I had to specify the broad areas in which advances will be made, they would include catalysis with metals, and the roles of metals in biology. I hope these will help with what all scientific advances have allowed society to achieve: better health, productivity, comfort, and happiness for all those fortunate enough to take advantage of such progress.

Why do you find chemistry inspiring?

I can make discoveries that potentially change how we view chemistry, at least in some small way. That might be a larger way, though, if I am lucky enough to be in the right place at the right time. Everyone wants to have a shot at changing the world – and, of course, get credit for doing so.

Professor Richard R. Schrock is the Frederick G. Keyes Professor of Chemistry at the Massachusetts Institute of Technology (MIT). In 2005 he was awarded the Nobel Prize in Chemistry (jointly with Yves Chauvin and Robert H. Grubbs) “for the development of the metathesis method in organic synthesis.” He also received the RSC’s Frankland Award in 2004. In January 2012, he began his four-year term as Chair of the Chemical Communications (ChemComm) editorial board.
(This interview is reproduced from RSC News, April 2012)
 
You can read more from Professor Schrock in a recent ChemComm Editorial and article.
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Top ten most accessed articles in March

This month sees the following articles in ChemComm that are in the top ten most accessed:-

Graphene quantum dots: emergent nanolights for bioimaging, sensors, catalysis and photovoltaic devices
Jianhua Shen, Yihua Zhu, Xiaoling Yang and Chunzhong Li
Chem. Commun., 2012, 48, 3686-3699, DOI: 10.1039/C2CC00110A

Carbon-gold core-shell structures: Formation of shells consisting of gold nanoparticles
Jerzy Choma, Dominik Jamioła, Katarzyna Augustynek, Michal Marszewski and Mietek Jaroniec
Chem. Commun., 2012, 48, 3972-3974, DOI: 10.1039/C2CC30372H

N-Heterocyclic carbene chemistry of iron: fundamentals and applications
Michael J. Ingleson and Richard A. Layfield
Chem. Commun., 2012, 48, 3579-3589, DOI: 10.1039/C2CC18021A

Self-assembling porphyrins and phthalocyanines for photoinduced charge separation and charge transport
Hiroshi Imahori, Tomokazu Umeyama, Kei Kurotobi and Yuta Takano
Chem. Commun., 2012, 48, 4032-4045, DOI: 10.1039/C2CC30621B

6-Substituted quinoline-based ratiometric two-photon fluorescent probes for biological Zn2+ detection
Xiangming Meng, Shuxin Wang, Yiming Li, Manzhou Zhu and Qingxiang Guo
Chem. Commun., 2012, 48, 4196-4198, DOI: 10.1039/C2CC30471F

Metal-free TEMPO-catalyzed oxidative C-C bond formation from Csp3-H bonds using molecular oxygen as the oxidant
Bo Zhang, Yuxin Cui and Ning Jiao
Chem. Commun., 2012, 48, 4498-4500, DOI: 10.1039/C2CC30684K

Enhanced isosteric heat of H2 adsorption by inclusion of crown ethers in a porous metal-organic framework
Hye Jeong Park and Myunghyun Paik Suh
Chem. Commun., 2012, 48, 3400-3402, DOI: 10.1039/C2CC17005A

Cobalt-catalyzed arylation of aldimines via directed C-H bond functionalization: addition of 2-arylpyridines and self-coupling of aromatic aldimines
Ke Gao and Naohiko Yoshikai
Chem. Commun., 2012, 48, 4305-4307, DOI: 10.1039/C2CC31114C

Gold-catalyzed amide synthesis from aldehydes and amines in aqueous medium
Gai-Li Li, Karen Ka-Yan Kung and Man-Kin Wong
Chem. Commun., 2012, 48, 4112-4114, DOI: 10.1039/C2CC17689K

Extending the family of Zn-based MOFs: synthetic approaches to chiral framework structures and MOFs with large pores and channels
Nianyong Zhu, Gerard Tobin and Wolfgang Schmitt
Chem. Commun., 2012, 48, 3638-3640, DOI: 10.1039/C2CC17357C

Why not take a look at the articles today and blog your thoughts and comments below.

Fancy submitting an article to ChemComm? Then why not submit to us today or alternatively contact us with your suggestions

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Ionic liquid drugs hit the spot

Robin-Rogers_ionic-liquid-research_250_tcm18-216842

Biologically active ionic liquids supported on mesoporous silica provide solid handling with fast and complete release in an aqueous environment © Andreea Cojocaru and Gabriela Gurau/The University of Alabama

Pharmaceutically active ionic liquids have been immobilised onto solid supports to enable liquid drugs to be administered in solid form. Scientists from the US and Europe hope that their work will make the pharmaceutical industry consider ionic liquids as a viable alternative to solid drugs.

Pharmaceutically active ionic liquids are more soluble and stable than solid drugs and they are better at getting across cell membranes. But they are difficult to prepare and are not easy to handle. Robin Rogers from the University of Alabama in the US and colleagues immobilised the liquids onto mesoporous silica to improve preparation and handling.

The team combined known active pharmaceutical ingredients (APIs) into new dual functioning liquid salts in two ways. ‘In the first, we combined an acidic API with a basic API simply by grinding or mixing them together,’ explains Rogers. ‘This produces a salt in which the proton has transferred from the acid to the base.’ In the second, they started with a cationic API and an anionic API and exchanged the inert counterions to produce a new salt of API1+ and API2-.

Read the full article in Chemistry World

Link to journal article
Pharmaceutically Active Ionic Liquids with Solids Handling, Enhanced Thermal Stability, and Fast Release

Katharina Bica ,  Hector Rodriguez ,  Gabriela Gurau ,  O. Andreea Cojocaru ,  Anders Riisager ,  R Fehrmann and Robin D. Rogers
Chem. Commun.,
2012, Accepted Manuscript, DOI: 10.1039/C2CC30959A

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Novel synthesis of iron catalyst complexes via C-H activation of imidazolium salts

Researchers from Lisbon have developed a mild and efficient catalytic system for reducing sulfoxides. They made the iron-N-heterocyclic carbene (NHC) catalysts (2) via C–H activation of an imidazolium pro-ligand (1) with commercially available Fe3(CO)12. This advance precludes the requirement for the strong bases traditionally employed in the synthesis of similar complexes. Additionally, iron is an economically attractive metal for use in catalysis owing to its abundance and is also non-toxic and therefore more environmentally friendly than other transition metals.

The combination of iron(ll) complex (2) with a silver salt and a silane reducing agent led to the conversion of a range of sulfoxides into the corresponding sulfides in good to excellent yields. Initial mechanistic probes suggest the existence of a free-radical based reaction pathway, although further studies are ongoing.

In this publication, Beatriz Royo’s group have demonstrated an interesting advance for the synthesis of iron-NHC complexes, which may find further utility in other catalytic processes.

Download the communication >

Posted on behalf of Alice Williamson, ChemComm web writer.

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Shining a light on fingerprint detection

Scientists in China have discovered a method for visualising latent fingerprints found at the scene of a crime, which they say is very simple, rapid, does not require professional forensic treatment and does not destroy the print.

Bin Su and co-workers from Zhejiang University, Hangzhou, noticed that the conjugated compound tetraphenylethene (TPE) adhered to the greasy ridges of fingerprints via a hydrophobic interaction. TPE is non-fluorescent in acetonitrile solution, but when light with a 365nm wavelength is shone onto the solution, the compound can lose the extra energy by rotating. However, when TPE sticks to the fingerprint, its molecules clump together (or aggregate). The aggregated molecules can no longer rotate, so instead, they release the energy as light. This phenomenon is known as aggregation induced emission (AIE) and has been used in sensors, but never as a means of detecting fingerprints.

Shining a light on fingerprint detection
The fingerprints were enhanced by aggregation induced emission of tetraphenylethene
© iStockphoto

Read the full story in Chemistry World

Link to journal article
Aggregation induced emission for the recognition of latent fingerprints
Yan Li ,  Linru Xu and Bin Su
Chem. Commun., 2012, 48, 4109-4111, DOI: 10.1039/C2CC30553D

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