Chemical Communications Blog

Germanium-bridged polymer for organic solar cells

25 Jan 2012

A team of scientists from the UK and US have made a novel germanium-bridged polymer that shows promise for organic solar cells.

Martin Heeney, at Imperial College London, and colleagues synthesised a heterocyclic monomer bridged with two germanium atoms. They co-polymerised it with an electron-accepting benzothiadiazole to give a polymer that, in contrast to the analogous C-bridged system, is semicrystalline.

Being able to design crystallinity into conjugated polymers in such a way is useful because crystalline polymers are better at transporting charge and hence offer more potential for solar cells. Heeney’s polymer exhibited power conversion efficiencies of over 5 % in bulk heterojunction solar cells. The team are now investigating the use of additives and co-solvents to increase this further.

Find out more – download Heeney’s ChemComm communication.

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Look into my MRI: Non-invasive detection of melanin formation

25 Jan 2012

By Fiona McKenzie, Executive Editor.

Magnetic Resonance Imaging (MRI) is used as a medical tool to image soft tissue. It can give insights into the physical state of brain, identify sports injuries and diagnose cancer without ionising radiation. Its main drawback is the low sensitivity of the contrast enhancing probes it uses. These are the paramagnetic metal complexes, often containing gadolinium or manganese, that distinguish between healthy and damaged tissue by altering the relaxation times of the water protons in the body. The challenge is to increase the concentration of the contrast reagents in the tissues.

One solution is to use nanocarriers to deliver a high concentration of the contrast agent to the specific site of interest. Silvio Aime and his team recently used the nanocarrier, apoferritin, to transport solid MnOOH, which was subsequently reduced to paramagnetic Mn²⁺. Their recent ChemComm details how they have now taken this one step further to find a way of generating the Mn²⁺ contrast agent using a naturally occurring reductant. The result: a probe for melanin.

Melanin is produced from the successive oxidation of tyrosine – a process that is up-regulated in malignant melanoma. Aime exploited this oxidation process by introducing MnOOH-loaded apoferritin into melanoma cells – the MnOOH was reduced, generating the contrast agent and enabling the cells to be successfully imaged by MRI.

in vivo MRI images of tumour-bearing mice before and after administration of the contrast agent loaded nanocarrier

The team tested the sensor on melanogenic cells (melanin-forming cells) against non-melanogenic cells. They demonstrated that the signal generated belonged only to the melanin-producing cells which had internalised the Mn(III)OOH–apoferriton payloads. Animal studies revealed enhanced signal intensity in melanogenic tumours.

This interesting research has the potential to provide non-invasive, early diagnoses of skin cancers and evaluate the development of tumours, critical for saving people’s lives. The in vivo sensor may also be used to monitor other processes involving massive oxidative processes. The work of Silvio Aime is one to watch.

To find out more, download the ChemComm article today…

Posted on behalf of Sarah Brown, web science writer for ChemComm.

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Mineral regulates early metabolism

16 Jan 2012

By Rachel Blakeburn.

Chinese scientists have taken a step towards further understanding the reactions that led to the origin of life by showing that a crucial metabolic process can be photocatalysed on the surface of a common mineral.

The citric acid or tricarboxylic acid cycle is central to almost all life and is used to generate energy from the conversion of acetate from fats, proteins and carbohydrates to carbon dioxide and water. Some bacteria run this cycle in reverse in a reductive tricarboxylic acid cycle (rTCA), making carbon compounds from carbon dioxide and water, and this has been suggested to be the central part of primordial metabolism.

Wei Wang from Harbin Institute of Technology and colleagues claim that early reactions to form biological molecules and metabolic pathways could have occurred on the surface of sulfide minerals in under-sea hydrothermal vents. This could explain why enzymes containing transition metal-sulfide clusters play a vital role in the metabolism of most organisms.

Early metabolic reactions could have happened on the surface of the mineral sphalerite (ZnS)

Read the full article in Chemistry World

Link to Article
Photocatalytic reversible amination of α-keto acids on a ZnS surface: implications for the prebiotic metabolism
Wei Wang, Qiliang Li, Bin Yang, Xiaoyang Liu, Yanqiang Yang and Wenhui Su
Chem. Commun., 2012, Advance Article
DOI: 10.1039/C2CC15665B

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Joint ChemComm–RSC Prizes and Awards Symposium in London

09 Jan 2012

By Joanne Thomson.

We are delighted to announce the forthcoming ChemComm–RSC Prizes & Awards Symposium in association with the RSC Analytical Division.

Date: Wednesday 22nd February 2012
Location: Imperial College London, UK
Time: 1300-1800

The purpose of this event is to bring together scientists in a stimulating and friendly environment to recognise the achievements of individuals in advancing the chemical sciences and also to foster collaborations. The symposium will appeal to academic and industrial scientists with an interest in analytical science, protein structure and interactions, and biosensors. Attendance at the symposium is FREE OF CHARGE and student participation is strongly encouraged.

The following distinguished scientists have agreed to speak:

Dr Perdita Barran, University of Edinburgh, UK (ChemComm sponsored speaker) – Resolving solution structures in the absence of solution
Professor Carol V Robinson, University of Oxford, UK (RSC Interdisciplinary Prize winner) – Membrane protein complexes at last
Professor G Marius Clore, NIDDK, National Institutes of Health, USA (RSC Centenary Prize winner) – Exploring sparsely-populated states of proteins and their complexes by paramagnetic and diamagnetic NMR
Professor Albert Heck, Utrecht University, the Netherlands (ChemComm sponsored speaker) – Modern biomolecular mass spectrometry and its role in studying virus structure, dynamics, and assembly
Professor R Graham Cooks, Purdue University, USA (RSC Centenary Prize winner) – Mass spectrometry simplified: ambient ionization and miniature mass spectrometers
Professor Anthony P F Turner, Linköpings University, Sweden (RSC Theophilus Redwood Award winner) – Biosensors: Sense and Sensibility

For further details and to register your interest, please contact Anne Horan.

***
The closing date for RSC Prizes and Awards 2012 is 15th January 2012. Find out more >
***

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Meet our author… Matthew Gibson

06 Jan 2012

By Will Dennis, Publishing Editor.

Matthew Gibson is a chemist working at the University of Warwick, UK. His research interests focus on the design of macromolecular structures which can interface with biological systems, and consequently all the work in his group is cross-disciplinary. Matthew took time out from his work to talk to ChemComm…

What initially inspired you to become a scientist?
I was always interested in the natural world, but really only became interested in chemistry during my A-levels. I had two very enthusiastic chemistry teachers who strongly encouraged me. We were able to undertake an extended lab project, and I found myself enjoying the challenge. At university I found myself drawn to the creativity of synthesis and how creative solutions can be used to gain fundamental understanding and innovative solutions.

What was your motivation behind the work described in your ChemComm article?
In my group, we are very interested in interfacing materials with biological systems. A key challenge is making these materials ‘smarter’, so that they have triggerable/programmable activity, but also to introduce degradability. A major hurdle to this is that the synthetic methodologies to obtain degradable materials are not tolerant to introducing functional groups e.g. biological ligands. Conversely, controlled radical polymerisations are tolerant of most functional groups, but these polymers are inherently non-degradable. To overcome these limitations we developed a methodology to introduce bioreducible (-S–S-) linkages into polymers derived from controlled radical polymerisation. We demonstrated that these polymers have interesting thermoresponsive behaviour, which can be ‘switched off’ by degradation.

Why did you choose ChemComm to publish your work?
I felt that both the synthetic methodology and also the applications of the materials we describe in the article would be of interest to readers with both chemistry and bioscience backgrounds. Considering the broad readership of ChemComm and the rapid publication times, it was really the best place to disseminate this work.

Where do you see your research heading next?
We are now extending the technology from our recent ChemComm paper to develop increasingly complex materials which have triggerable interactions with cell membranes. We are broadening the scope of the monomers used and also undertaking biological studies.

What do enjoy doing in your spare time?
Since I lived in Switzerland for 3 years, skiing and alpine hiking are always top of my list! Otherwise, reading a good book or heading to the movies.

If you could not be a scientist, but could be anything else, what would you be?
It would be something outdoor such as a national park warden, or alternatively running a pub/brewery – in an ideal world, I’d combine the two.

Matthew has recently published two communications in ChemComm touching on the degradable thermoresponsive polymers described here and another on gold and micelle-based polymer nanoparticles.

Degradable thermoresponsive polymers which display redox-responsive LCST Behaviour
Daniel J. Phillips and Matthew I. Gibson
Chem. Commun., 2012, 48, 1054-1056

The critical importance of size on thermoresponsive nanoparticle transition temperatures: gold and micelle-based polymer nanoparticles
Nga Sze Ieong, Konstantinos Brebis, Laura E. Daniel, Rachel K. O’Reilly and Matthew I. Gibson
Chem. Commun., 2011, 47, 11627-11629

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Welcome to the year of 100 issues!

01 Jan 2012

By Joanne Thomson.

Happy New Year!

2012 brings exciting changes to ChemComm, including a Nobel Prize-winning Chair and an increase in frequency to 100 issues.

Read our Editorial where we reflect on how a successful 2011 has paved the way for the biggest year in the history of ChemComm.

And find out what our new Chair Richard Schrock thinks…..

Find out about the move to 100 issues >

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3 days until 100 issues…

29 Dec 2011

By Joanne Thomson.

….and did you know….?

ChemComm communications should be no longer than 3 journal pages and, of course, report urgent, high quality and novel research.

Have you read our author guidelines? They are full of useful information about preparing your communication so please check them out before submitting your manuscript.

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5 days until 100 issues…

27 Dec 2011

By Joanne Thomson.

….and did you know….?

5 is the number of ChemComm symposia held to date. We’ve brought together scientists in stimulating and friendly environments in Japan, China and Korea to disseminate the latest hot research and foster collaborations between the researchers and the universities involved.

Read Editor Robert Eagling’s blog from this year’s 5th ChemComm Symposium to find out more about his visit to Kyoto, Lanzhou and Nankai.

And stay tuned for news of the next ChemComm symposium, taking place at Imperial College London in February. Preliminary details >

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7 days until 100 issues…

25 Dec 2011

By Joanne Thomson.

….and did you know….?

ChemComm published 7 web-based thematic issues in 2011:

We are still adding articles to some of these issues so please visit the themed issue webpages to view the latest research.

If you have an idea for a web theme, let us know! Email the Editorial Office >

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10 days until 100 issues…

22 Dec 2011

By Joanne Thomson.

….and did you know….?

ChemComm has 10 world-leading Associate Editors who handle submissions within their areas of expertise. You can select one of their Editorial Offices (or the Cambridge Editorial Office) when you submit your article.

	Associate Editor	Expertise
	Antonio Echavarren	Organic Chemistry & Catalysis
	Steven De Feyter	Nanoscience & Supramolecular Chemistry
	Daniel Gamelin*	Inorganic Materials & Nanoscience
	Michael Krische*	Organic Chemistry
	Can Li	Physical Chemistry, Heterogeneous Catalysis & Spectroscopy
	Jean-Louis Reymond	Chemical Biology
	Manfred Scheer	Inorganic & Organometallic Chemistry
	Jonathan Sessler*	Supramolecular & Macrocyclic Chemistry
	Jonathan Steed	Supramolecular Chemistry
	Don Tilley*	Inorganic & Organometallic Chemistry