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Archive for the ‘News’ Category

New antibiotic with reduced risk of future bacterial resistance

19 Nov 2012

Biofilm growth of the bacteria, P. aeruginosa, is responsible for many chronic infections in patients and presents a major challenge for the medical industry since these bacteria are largely resistant to antibiotics, disinfectants and patients’ natural immune defences.

UK scientists have developed a new antibiotic based on gallium metal ions complexed with cellulose which effectively displays antibacterial activity against biofilms of P.aeroginosa. Risk of future resistance to these antibiotics is also reduced as they work by an entirely different mechanism to traditional antibiotics.

A disc diffusion assay shows the inhibitory action of the gallium-carboxymethyl cellulose on P.aeroginosa. The white arrow shows the spherical transparent inhibition zone.

This article is particularly topical considering recent UK news headlines on antibiotic resistance. Download the article now…

Effect of Novel Antibacterial Gallium-Carboxymethyl Cellulose on Pseudomonas aeruginosa
Sabeel P Valappil, Humphrey H.P. Yiu, Laurent Bouffier, Christopher Keith Hope, Gary Evans, John B Claridge, Susan M Higham and Matthew J Rosseinsky

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Ruthenium catalyst for cancer treatment

19 Nov 2012

Scientists from Germany have designed a new complex which inhibits enzymes and reduces tumour cell growth.

The drug complex consists of N-heterocyclic carbene ligands coordinated to a ruthenium metal centre. Ruthenium N-heterocyclic carbene compounds are largely popular due to their catalytic properties but very little attention has been paid to the biological activity of these species.

Why not download the article now to find out what the team did…?

Evaluation of arene ruthenium(II) N-heterocyclic carbene complexes as organometallics interacting with thiol and selenol containing biomolecules
Luciano Oehninger, Maria Stefanopoulou, Hamed Alborzinia, Julia Schur, Stephanie Ludewig, Kazuhiko Namikawa, Alvaro Muñoz-Castro, Reinhard W. Köster, Knut Baumann, Stefan Wölfl, William S. Sheldrick and Ingo Ott

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Persistently luminescent: long lasting phosphor MOF

18 Oct 2012

In recent years, metal organic frameworks (MOFs) have received a great deal of research interest due to their application for gas storage, catalysis and for use as sensors. By choosing different metals and organic linkers, the pore shape and size can be tuned for one’s particular need.

In this article, Yue-ying Ching and colleagues have reported a MOF which has green persistent luminescence. To the researchers’ knowledge, persistent luminescence has not been reported in MOF’s before. The luminescence lasts for about 1 second which means that this material can be classed as a long lasting phosphor (LLP). LLPs have decay times of seconds, minutes and in some cases hours making them useful for LEDs and emergency lighting, amongst others.

The preparation of conventional LLPs requires extreme reaction conditions (temperatures of at least 1000ºC!). This new MOF was synthesized using solvothermal conditions at 115ºC. This work provides an exciting new route towards LLPs, without the need for co-dopants or extreme synthesis conditions.

To find out more, download the article now….

Promising long-lasting phosphor material: a novel metal–organic framework showing intriguing luminescent performance
Feng Luo, Gong-Ming Sun, An-min Zheng, Shi-xun Lian, Ying-liang Liu, Xue Feng Feng and Yue-ying Chu.

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Ligand Effects on the Catalytic Activity of Ruthenium Nanoparticles

20 Sep 2012

When metal nanoparticles are used as catalysts, they can have a tendency to aggregate. Especially when the metal nanoparticles (NPs) are not functionalized as there isn’t anything to oppose the Van der Waals forces. Aggregation or coalescence of the NPs can lead to a decrease in catalytic activity. Two strategies have been developed for stabilisation — addition of a ligand post NP synthesis or inclusion of a coordinating ligand into the cation of an ionic liquid (IL).

In a previous Dalton Transactions article, (Dalton Trans., 2011, 40, 4660–4668) the stability of ruthenium nanoparticles (RuNPs) was improved by the combination of ILs and stabilising ligands to produce a recyclable catalytic system for the hydrogenation of toluene. In this new article, Agilio Padua and colleagues have taken this one step further and investigated the effect of various ligands on the catalytic activity of RuNPs in an IL.

RuNPs were prepared in an IL, and in the presence and absence of a series of different ligands. Padua and colleagues discover that the activity of RuNPs with respect to the catalytic hydrogenation of cyclohexadiene, styrene and limonene increased with σ-donor ligands (water and octylamine) but decreased with π-acceptor ligands (carbon monoxide, phenylphosphine and diphenylphosphine). This paper demonstrates how RuNPs as catalysts are remarkably similar to homogenous catalysts in that their activity and selectivity can be controlled by σ-donor and π-acceptor ligands.

Download the full paper to find out more…

Ligand effect on the catalytic activity of ruthenium nanoparticles in ionic liquids
Santini Catherine, Paul S Campbell, Gorka Salas, Karine Philippot, Agilio A.H. Padua and Margarida Costa Gomes
Dalton Trans., 2012

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New Routes to Versatile Thorium(IV) Precursors

20 Sep 2012

Anhydrous metal halides and their soluble Lewis base-adduct relatives are ubiquitous starting materials in inorganic and organometallic chemistry, serving as extremely versatile precursors to myriad derivatives. As a result, reliable and straight-forward protocols for accessing such species allow researchers to deploy their carefully crafted ligands and explore unexpected reactivity, as well as fully unveil the richness of previously reported systems.

Indeed, only a handful of thorium(IV) halide starting materials are commonly utilized, and as thorium turnings are becoming increasingly hard to come by, new routes to anhydrous thorium(IV) halides from available thorium(IV) salts are crucial. Jaqueline Kiplinger and co-workers have recently reported a facile synthesis of ThI₄(dme)₂and have demonstrated its keen ability to be derivatized. As molecular actinide iodide complexes have been shown to offer markedly differing reactivities from their chloride counterparts, this contribution may allow for yet unseen reactivity at Th(IV) centres, and maybe even provide less tumultuous access to the exceptionally rare Th(III) oxidation state.

Check out the full article to read more about this new precursor and related complexes:

Thorium-mediated ring-opening of tetrahydrofuran and the development of a new thorium starting material: preparation and chemistry of ThI₄(DME)₂
Nicholas Travia, Marisa Monreal, Brian Scott and Jaqueline Kiplinger,
Dalton Transactions, 2012

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The first Gold for Gold article has been published!

11 Sep 2012

We are very pleased to announce that the first Gold for Gold open access article has been published in Dalton Transactions. The Gold for Gold initiative was recently launched and rewards UK RSC Gold subscribers with credits to publish their RSC articles via Open Science, the RSC’s Gold Open Access option. The article by Stephen J. Archibald et al. is free to download to all

CXCR4 chemokine receptor antagonists: nickel(II) complexes of configurationally restricted macrocycles
Rachel Smith , Dana Huskens, Dirk Daelemans, Ryan E. Mewis, Courtney D. Garcia, Amy N. Cain, TaRynn N. Carder Freeman, Christophe Pannecouque, Erik De Clercq, Dominique Schols, Timothy J. Hubin and Stephen J. Archibald
Dalton Trans., 2012, 41, 11369-11377
DOI: 10.1039/C2DT31137B

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

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Versatile Copper Ensemble for Cyanide Detection

29 Aug 2012

Cyanide compounds can be highly toxic as the cyanide anion inhibits an enzyme in the electron transport chain, cytochrome c oxidase. The inhibition of this enzyme means that cells in the body can no longer produce ATP aerobically for energy which can eventually affect the heart and the central nervous system.

Some industrial processes such as gold mining make use of cyanide ions and the accidental release of these ions can cause serious problems. The potassium salt of cyanide is also used as a terror chemical agent. As such, there is a need for more efficicent detection of cyanide ions with lower detection limits than methods which have been used previously.

Manoj Kumar and his team at Guru Nanak Dev University, India have synthesized a triazole ( five membered ring with 3 nitrogen and 2 carbon atoms) modified triphenylene (four fused benzene rings) which can selectively complex copper²⁺ ions.

The triphenylene based copper ensemble was shown using UV-vis and fluorescence spectroscopy to give a selective response for cyanide ions, even in the presence of blood serum and bovine serum albumin. This paper highlights the potential versatility of the copper ensemble for cyanide detection in different environments.

To read more about the detection of sodium cyanide in tap water and solid state detection of cyanide using the copper ensemble read the full article.

Triphenylene based copper ensemble for the detection of cyanide ions
Vandana Bhalla , Hardev Singh and Manoj Kumar
Dalton Trans., 2012

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Dalton Transactions Blog

Archive for the ‘News’ Category

New antibiotic with reduced risk of future bacterial resistance

Ruthenium catalyst for cancer treatment

Top ten most accessed articles in September

Persistently luminescent: long lasting phosphor MOF

Top ten most accessed articles in August

Ligand Effects on the Catalytic Activity of Ruthenium Nanoparticles

New Routes to Versatile Thorium(IV) Precursors

Top ten most accessed articles in July

The first Gold for Gold article has been published!

Versatile Copper Ensemble for Cyanide Detection

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