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Metal-free resins can drive down cost of solar energy

08 Oct 2012

Solar farm Costly metals in some solar cells could be replaced by cheap resins, according to Korean research.

Dye-sensitised solar cells (DSSCs) are an important class of solar cells, which demonstrate a number of important attributes, such as low cost, flexibility and good efficiency. It is perhaps the most actively researched solar cell technology. However, it is still hindered by expensive components.

Currently, a third of the cost of DSSCs could go towards the noble metal-based dyes used to sensitise the titania photocatalyst, allowing it to harvest the more useful visible part of the spectrum. However, Wonyong Choi and his group at Pohang University of Science and Technology have replaced these dyes with a simple and cheap phenolic resin.

Read more in Chemistry World or read Choi’s communication in ChemComm.

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ChemComm celebrates its first Gold for Gold communication

08 Oct 2012

Eugen Stulz (University of Southampton) and colleagues are the first ChemComm authors to publish a communication as part of our Gold for Gold initiative. Gold Image

Their communication, entitled ‘A DNA based five-state switch with programmed reversibility’ is now free to access for all.

‘I’m delighted that Eugen’s communication is the first open access communication to be published in ChemComm using the RSC’s Gold for Gold programme,’ says Phil Gale, Head of Chemistry at the University of Southampton. ‘This open access programme will allow us to showcase our research to a much wider audience.’

Gold for Gold is an innovative initiative rewarding UK RSC Gold customers with credits to publish a select number of papers in RSC journals via Open Science, the RSC’s Gold Open Access option.

More information on Gold for Gold is available on our website. If you have any questions on the procedure, or are an interested customer from outside the UK, please contact goldforgold@rsc.org.

Also of interest:
Gold for Gold – First Open Access credit used by University of Hull

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Biocatalysis: an article collection

05 Oct 2012

Beers, wines and cheeses are enjoyed around the world today and have been for millennia. In fact the practices of brewing and cheese-making pre-date recorded history so it is difficult to accurately determine when we first started using naturally occurring enzymes and microorganisms to create valuable (and in this case, tastier!) products.

Biocatalysts are of course used in far more diverse applications than the creation of food-stuffs, including in many organic syntheses and in the generation of fine chemicals. Due to their natural design, they can offer superior selectivity for particular products and have a far lower environmental impact than many traditional catalysts. Our knowledge and understanding of biocatalysts has increased dramatically in the last few decades, which has allowed us to develop biologically modified and biomimetic catalysts for a range of applications.

To keep you up to date with the latest advances in this rapidly expanding field we have collected together these high impact articles and made them free to access until the 31^st October!

Click here for the full list of free articles

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Lewis acidity of metal ions investigated in the gas phase

03 Oct 2012

In aqueous solutions metal ions can promote acidity via the hydrolysis reaction. This is measured by a hydrolysis constant, which has previously been correlated to the ratio of the ion’s charge to size. Unfortunately lead and tin stubbornly refuse to fit this correlation; additional factors must be at work.

Anthony Stace and team investigated further by studying the minimum number of water molecules needed to stabilise a dication complex in the gas phase against spontaneous hydrolysis (called Coulomb fission in the gas phase). They found an extraordinarily good correlation between the number of water molecules required and the metal ion’s hydrolysis constant in aqueous solution.

What about those stubborn dications, lead and tin? They fit within the trend, requiring a surprising 11 and 26 water molecules to stabilise them respectively. This work suggests that Lewis acidity of metal ions is determined, in part, by the requirement that the ions remain fully solvated.

Plot of acidity constant against minimum number of water molecules required to stabilise the complex against Coulomb fission.

To find out more, download the ChemComm article today.

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A look at Gregynog 2012

03 Oct 2012

The annual Gregynog Synthesis Meeting was recently held at Gregynog Hall (Thursday 13^th to Saturday 15^th September), amidst the stunning beauty of mid-Wales and accompanied by fair weather. A group of 55 chemists came together to discuss recent progress in organic synthesis. As befits such a broad remit, the range of stakeholders present was pronounced with academic, industrial and scientific publishing attendees all present. As synthesis is an enabling and under-pinning scientific discipline, it was perhaps not surprising to see the range of contexts in which speakers discussed their synthesis. Catalysis, methodology and natural product chemistry were not-surprisingly representative; however, the audience was also treated to medicinal, process and supramolecular chemistries.

The relaxed and residential character of this event helps to encourage a collegiate ethos, helping to welcome younger chemists into the wider synthesis community. Such an ethos facilitates the discussion of initial results on new and adventurous projects in a supportive environment. In this regard, the fresh-faced Dr David France (University of Glasgow) struck a chord with the audience through his imaginative Pd-catalysis work.

The meeting is structured around the complementary formats of a number of short “chalk+talk” presentations (15 minutes with lively discussion and questions) supporting the two main keynote speakers in the evening, one of which has travelled beyond these shores. These keynote speakers have the opportunity to convey what exactly has made them the international names they are. What does the genesis of an idea require? How do the independent research strands in a research group interact with each other? And, importantly for the younger colleagues, how are difficult scientific challenges conquered? The Thursday evening saw Prof Jonathan Clayden (University of Manchester) present the Chemical Communications keynote talk and embraced the meeting’s ethos with a career spanning discussion of the intertwining chemistry problems his group have tackled. The Friday evening session had Prof Dirk Trauner (LMU, Münich) present the Nature keynote talk. Earlier in the meeting, a member of the organising committee had suggested that his talk would be all the better, fitting the meeting’s remit, if he presented lots of “failed reactions” as a vehicle to conveying how he tackled organic synthesis problems. In this respect, it was a delight to later find, in my opinion, the most visually striking slide in a chemistry presentation I have yet seen. Prof Trauner went the extra mile in passing on his undoubted experience in synthesis problem-solving with some exquisite answers and suggestions. These keynote talks, as indeed were the short presentations, were interspersed with comments, suggestions and questions from the floor, indicative of the discerning yet approachable audience.

Finally, the Dave Kelly cup is awarded annually to a chemist who has engaged the audience with difficult concepts in a concise manner, with clarity at the chalk board. This prize is awarded in memory of our colleague Dr Dave Kelly, who was, for many years, synonymous with this important pillar in the synthesis calendar. Without doubt, Dr Steve Goldup (QMUL) was the chemist who hit the spot in this regard. The cup is on the way to the East End as I type.

Posted on behalf of Dr David Carbery, University of Bath

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ChemComm and the chemistry-biology interface

20 Sep 2012

The chemical sciences make a huge contribution to solving challenges in the biological sciences.

So quite rightly, articles at the chemistry–biology interface make up an important part of ChemComm.

Here’s a selection of some recent articles, all free to access until 19th October:

Nucleic acid aptamers: an emerging frontier in cancer therapy
Guizhi Zhu, Mao Ye, Michael J. Donovan, Erqun Song, Zilong Zhao and Weihong Tan
Chem. Commun., 2012, DOI: 10.1039/C2CC35042D

Picomolar level profiling of the methylation status of p53 tumor suppressor gene by label-free electrochemical biosensor
Po Wang, Hai Wu, Zong Dai and Xiaoyong Zou
Chem. Commun., 2012, DOI: 10.1039/C2CC35615E

Oriented Immobilization of Oxyamine-Modified Proteins
Long Yi, Yong-Xiang Chen, Po-Chiao Lin, Hendrik Schroeder, Christof M. Niemeyer, Yaowen Wu, Roger S. Goody, Gemma Triola and Herbert Waldmann
Chem. Commun., 2012, DOI: 10.1039/C2CC35237K

Colorimetric detection of single-nucleotide polymorphisms with a real-time PCR-like sensitivity
Wei Shen, Huimin Deng, Alan Kay Liang Teo and Zhiqiang Gao
Chem. Commun., 2012, DOI: 10.1039/C2CC35070J

A bioresponsive controlled-release biosensor using Au nanocages capped with an aptamer-based molecular gate and its application in living cells
Wei Wang, Tao Yan, Shibin Cui and Jun Wan
Chem. Commun., 2012, DOI: 10.1039/C2CC33165A

Cascade imaging of proteolytic pathway in cancer cell using fluorescent protein-conjugated gold nanoquenchers
Kyoungsook Park, Jinyoung Jeong and Bong Hyun Chung
Chem. Commun., 2012, DOI: 10.1039/C2CC35687B

Eager for more?

Check out the Nucleic acids: new life, new materials web theme, jointly organised with OBC and RSC Advances.

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Glucometers altered to detect HIV

19 Sep 2012

Glucometers used by diabetic patients can be altered to detect HIV-related DNA sequences, say scientists in China.

The commercially available personal glucometer has been the most successful point-of-care (POC) device up to date. But the glucometer only responds to glucose. Extending its use to monitoring different types of targets would potentially revolutionise POC technology.

The team used invertase, an enzyme that catalyses the hydrolysis of sucrose into glucose, to interpret DNA recognition events into readouts measurable by the glucometer.

They loaded nanoparticle amplification labels with invertase, which, through target/probe DNA hybridisations, catalysed the conversion of sucrose on the sensing surface to glucose. They could detect as low as 0.5pM of target DNA. While they demonstrate the method with HIV DNA, it could potentially used to detect different DNAs.

Link to journal article
Sensitive point-of-care monitoring of HIV related DNA sequences with a personal glucometer
J Xu et al
Chem. Commun., 2012, DOI: 10.1039/c2cc35941c

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Improved organocatalyst

12 Sep 2012

UK scientists have developed a scalable, resolution-free synthesis of a helical DMAP organocatalyst.

In 2011 Dave Carbery (University of Bath) and colleagues made a helicene catalyst that they say was the most active chiral DMAP-like nucleophilic catalyst (DMAP = 4-dimethylamino pyridine). It was an effective catalyst for the acylative kinetic resolution of chiral secondary alcohols. With it, the team achieved reactions on a gram scale using only 1mg of catalyst – a 0.05mol% loading. However, the catalyst needed HPLC resolution.

They are now able to make more than 1g of the helical DMAP without any resolution. They say that it is also possible to do late-stage functionalisation.

Link to journal article
Point-to-helical chirality transfer for a scalable and resolution-free synthesis of a helicenoidal DMAP organocatalyst
M R Crittall, N W G Fairhurst and D R Carbery
Chem. Commun., 2012, DOI: 10.1039/c2cc35583c

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Refinery test for mesostructured zeolite

12 Sep 2012

The Y zeolite is used as a catalyst for fluid catalytic cracking. It has a high surface area and large pores and is thermally and hydrothermally stable. But scientists are working on improving the catalyst for a better performance. One reason is that the 7.4Å micropores are limited in terms of size of hydrocarbon that they can take in. The process involves diffusion of large hydrocarbon molecules into the crystals and diffusion of the desired intermediate cracking products (diesel or light oil, gasoline and liquefied petroleum gases) out.

Introducing wider pores allows large hydrocarbon molecules to go through the process. Scientists from Spain had recently carried out a templating process (using a surfactant) to introduce highly controlled mesoporosity into zeolites. This led to improved catalytic selectivity, in which more gasoline, light oil and liquefied petroleum gas were obtained.

The team have now scaled up the catalyst and tested its hydrothermal stability and catalytic cracking performance in a refinery. The catalyst showed much better product selectivity compared to the current catalyst, says the team.

Link to journal article
A mesostructured Y zeolite as a superior FCC catalyst – from lab to refinery
J Garcia-Martinez, K Li and G Krishnaiah
Chem. Commun., 2012, DOI: 10.1039/c2cc35659g

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Organometallics in catalysis: an article collection

31 Aug 2012

Perhaps the most well-known applications of organometallics in catalysis are the Ziegler–Natta catalysts which are used to generate polymers; the catalysts are made up of mixtures of transition metal halides and organo-aluminium complexes. Karl Ziegler and Giulio Natta were awarded the 1963 Nobel Prize in Chemistry for their discovery and development of the catalysts, which today are the most commonly used catalysts for the manufacture of polythene.

The esteemed history of organometallics is not to be under-estimated and includes Grignard’s reagents, the Heck reaction, Schrock catalysts, Grubbs’ catalysts and the Suzuki Coupling to name just a few. Organometallic compounds have revolutionised science and industry and to keep you up to date with the latest break-through research being made across all areas of organometallics in catalysis, we have made this cross-journal article collection free until 26^th September.

Organometallic hydrogen transfer and dehydrogenation catalysts for the conversion of bio-renewable alcohols, Andrew C. Marr, Catal. Sci. Technol., 2012, 2, 279-287

Synthesis of functionalized thiophenes and oligothiophenes by selective and iterative cross-coupling reactions using indium organometallics, M. Montserrat Martínez, Miguel Peña-López, José Pérez Sestelo and Luis A. Sarandeses, Org. Biomol. Chem., 2012, 10, 3892-3898

Homogeneous and heterogeneous catalysts for multicomponent reactions, Maria José Climent, Avelino Corma and Sara Iborra, RSC Adv., 2012, 2, 16-58

Amine directed Pd(II)-catalyzed C–H bond functionalization under ambient conditions, Benjamin Haffemayer, Moises Gulias and Matthew J. Gaunt, Chem. Sci., 2011, 2, 312-315

Metal–ligand bifunctional activation and transfer of N–H bonds, Kilian Muñiz, Anton Lishchynskyi, Jan Streuff, Martin Nieger, Eduardo C. Escudero-Adán and Marta Martínez Belmonte, Chem. Commun., 2011, 47, 4911-4913

Symmetrical and unsymmetrical pincer complexes with group 10 metals: synthesis via aryl C–H activation and some catalytic applications, Jun-Long Niu, Xin-Qi Hao, Jun-Fang Gong and Mao-Ping Song, Dalton Trans., 2011, 40, 5135-5150

Well-defined copper(I) complexes for Click azide–alkyne cycloaddition reactions: one Click beyond, Silvia Díez-González, Catal. Sci. Technol., 2011, 1, 166-178

Access to chiral α-bromo and α-H-substituted tertiary allylic alcohols via copper(I) catalyzed 1,2-addition of Grignard reagents to enones, Ashoka V. R. Madduri, Adriaan J. Minnaard and Syuzanna R. Harutyunyan, Org. Biomol. Chem., 2012, 10, 2878-2884

Catalytic versus stoichiometric dehydrocoupling using main group metals, Robert J. Less, Rebecca L. Melen and Dominic S. Wright, RSC Adv., 2012, 2, 2191-2199

An improved catalyst architecture for rhodium(III) catalyzed C–H activation and its application to pyridone synthesis, Todd K. Hyster and Tomislav Rovis, Chem. Sci., 2011, 2, 1606-1610

Continuous flow organometallic catalysis: new wind in old sails, Ulrich Hintermair, Giancarlo Franciò and Walter Leitner, Chem. Commun., 2011, 47, 3691-3701

Organometallic reactivity: the role of metal–ligand bond energies from a computational perspective, Natalie Fey, Benjamin M. Ridgway, Jesús Jover, Claire L. McMullin and Jeremy N. Harvey, Dalton Trans., 2011, 40, 11184-11191

An introduction to X-ray absorption spectroscopy and its in situ application to organometallic compounds and homogeneous catalysts, Ryan C. Nelson and Jeffrey T. Miller, Catal. Sci. Technol., 2012, 2, 461-470

Palladium-catalyzed cross-coupling reactions of organogold(I) phosphanes with allylic electrophiles, Miguel Peña-López, Miguel Ayán-Varela, Luis A. Sarandeses and José Pérez Sestelo, Org. Biomol. Chem., 2012, 10, 1686-1694

Transition metal complexes with strong absorption of visible light and long-lived triplet excited states: from molecular design to applications, Jianzhang Zhao, Shaomin Ji, Wanhua Wu, Wenting Wu, Huimin Guo, Jifu Sun, Haiyang Sun, Yifan Liu, Qiuting Li and Ling Huang, RSC Adv., 2012, 2, 1712-1728

Mechanism of the gold-catalyzed cyclopropanation of alkenes with 1,6-enynes, Patricia Pérez-Galán, Elena Herrero-Gómez, Daniel T. Hog, Nolwenn J. A. Martin, Feliu Maseras and Antonio M. Echavarren, Chem. Sci., 2011, 2, 141-149

A dual organic/organometallic approach for catalytic ring-opening polymerization, Estefanía Piedra-Arroni, Pierre Brignou, Abderrahmane Amgoune, Sophie M. Guillaume, Jean-François Carpentier and Didier Bourissou, Chem. Commun., 2011, 47, 9828-9830

Half-titanocenes for precise olefin polymerisation: effects of ligand substituents and some mechanistic aspects, Kotohiro Nomura and Jingyu Liu, Dalton Trans., 2011, 40, 7666-7682

Exploring the versatility of a bis(phosphinimine) pincer ligand: effect of sterics on structure and lactide polymerization activity of cationic zinc complexes, Craig A. Wheaton and Paul G. Hayes, Catal. Sci. Technol., 2012, 2, 125-138

Enantioselective Friedel–Crafts alkylation of indole derivatives catalyzed by new Yb(OTf)3-pyridylalkylamine complexes as chiral Lewis acids, Guillaume Grach, Aurelia Dinut, Sylvain Marque, Jérôme Marrot, Richard Gil and Damien Prim, Org. Biomol. Chem., 2011, 9, 497-503

Mononuclear and dinuclear complexes of manganese(III) and Iron(III) supported by 2-salicyloylhydrazono-1,3-dithiane ligand: synthesis, characterization and magnetic properties, Weiwei Zuo, Vitor Rosa, Clarisse Tourbillon, David Specklin, Cheaib Khaled, Mohamedally Kurmoo and Richard Welter, RSC Adv., 2012, 2, 2517-2526

Design and Preparation of New Palladium Precatalysts for C-C and C-N Cross-Coupling Reactions, Nicholas Bruno, Stephen Buchwald and Matthew T Tudge, Chem. Sci., 2012, Accepted Manuscript

Negishi cross-coupling of secondary alkylzinc halides with aryl/heteroaryl halides using Pd–PEPPSI–Ipent, Selçuk Çalimsiz and Michael G. Organ, Chem. Commun., 2011, 47, 5181-5183

Catalytic dehydrogenation of dimethylamine borane by group 4 metallocene alkyne complexes and homoleptic amido compounds, Torsten Beweries, Sven Hansen, Monty Kessler, Marcus Klahn and Uwe Rosenthal, Dalton Trans., 2011, 40, 7689-7692

Bimetallic aluminium(acen) complexes as catalysts for the synthesis of cyclic carbonates from carbon dioxide and epoxides, Michael North and Carl Young, Catal. Sci. Technol., 2011, 1, 93-99

Planar chiral (η5-cyclohexadienyl)- and (η6-arene)-tricarbonylmanganese complexes: synthetic routes and application, Francoise Rose-Munch and Eric Rose, Org. Biomol. Chem., 2011, 9, 4725-4735

Iron-catalysed reduction of carbonyls and olefins, Bryden A. F. Le Bailly and Stephen P. Thomas, RSC Adv., 2011, 1, 1435-1445

Palladium-catalyzed selective oxidative olefination and arylation of 2-pyridones, Yuye Chen, Fen Wang, Aiqun Jia and Xingwei Li, Chem. Sci., 2012, Advance Article

Hydrogenation of imino bonds with half-sandwich metal catalysts, Chao Wang, Barbara Villa-Marcos and Jianliang Xiao, Chem. Commun., 2011, 47, 9773-9785

Rational design of diphosphorus ligands – a route to superior catalysts, Jason A. Gillespie, Deborah L. Dodds and Paul C. J. Kamer, Dalton Trans., 2010, 39, 2751-2764

For even more articles, take a look at the Dalton Transactions Themed Issue d0 organometallics in catalysis or browse through over 30 RSC Journals covering topics across the chemical sciences.

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