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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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No stone left unturned at Dalton Discussion 13

20 Sep 2012

This year’s Dalton Discussion meeting was based at the University of Sheffield and focused on the topic of Inorganic Photophysics and Photochemistry – Fundamentals and Applications.

The 3 day programme was rich with contributions from Keynote speakers, Richard Eisenberg, Majed Chergui, Peter Ford and Luisa De Cola; Invited speakers, Craig Hill, David Parker, and Chantal Daniel; amongst numerous other excellent presenations from researchers across the international community.


Majed Chergui and Andrea Barbieri	Richard Eisenberg	Craig Hill

The Dalton Discussion format differs slightly from other conferences in that speakers are alloted short 5-10 minute slots to deliver a snappy overview of their latest research based on the contents of their article which will shortly be published in a themed issue of Dalton Transactions.

For every 3 presentations, there follows an hour long discussion amongst the delegates – an excellent opportunity for researchers to get down to the gritty detail of the experiments, understand any tricky concepts, and offer alternative ideas to take the research forward. It was great to see even the graduate students asking questions – something that is sadly, rarely seen at conferences.

The poster sessions were also of great success. Many congratulations to Sven Hansen, Elizabeth Bagaley and Lucy Jones who won the Dalton Transactions, ChemComm and RSC Books poster prizes, respectively.


Otto Horvath in conversation with Peter Burks, student of Peter Ford at UCSB	From left to right: Lucy Jones (University of Manchester), Sven Hansen (Rostock University), Elizabeth Baggaley (University of Sheffield).	No conference is complete without networking at the welcome reception

I am already very much looking forward to what next year’s Dalton Discussion meeting has to offer – which will be adopting a new and improved format for article submission. Watch this space…

Many thanks go to Mike Ward for providing photographs and also for organising such an excellent meeting!

Also of interest…
See here for the RSC’s report on Solar Fuels and Artificial Photosynthesis: Science and innovation to change our future energy options

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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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From double-decker to quintuple-decker: single-molecule magnetic behaviour and f-f interactions

04 Sep 2012

This Hot Article from Masahiro Yamashita and Keiichi Katoh investigates the interactions among the 4f electrons of some multiple-decker Tb³⁺ and Dy³⁺ complexes, revealing the importance of molecular symmetry and coordination geometry.

Multiple-decker phthalocyaninato dinuclear lanthanoid(III) single-molecule magnets with dual-magnetic relaxation processes

Correlation between the χM′′(T) peak blocking temperature and the distance between the two Tb(III) ions

Single molecule magnets (SMMs) exhibit superparamagnetism at the molecular scale and have potential application in quantum computing, information storage and magnetic refrigeration. Understanding the relationship between the local environment of complexes and their magnetic properties is important to develop new SMMs with desirable magnetic relaxation behaviours.

Download the paper to see the full details of the team’s discoveries

Multiple-decker phthalocyaninato dinuclear lanthanoid(III) single-molecule magnets with dual-magnetic relaxation processes
Keiichi Katoh, Yoji Horii, Nobuhiro Yasuda, Wolfgang Wernsdorfer, Koshiro Toriumi, Brian K. Breedlove and Masahiro Yamashita

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Organometallics in catalysis: an article collection

29 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 for the manufacture of polythene.

The esteemed history of organometallics are not to be under-estimated and include 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 the 26^th September.

Click here for the full list of free articles

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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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Inspiring inorganic chemists to make their mark in medicine

29 Aug 2012

Declan Gaynor and Darren Griffith discuss how medicinal inorganic chemistry is currently flourishing in this Dalton Transactions Perspective. Understanding the role of metals in biological systems is very important for drug design; the predictability and control of inorganic complexes make fine-tuning the properties of drugs incorporating such complexes a real possibility. Metal-based compounds are already routinely administered on a regular basis and this Perspective encourages chemists to further investigate inorganic therapeutic and diagnostic medicine by looking at previous successes, e.g. MRI contrast agents, then moving onto current challenges such as antibacterial compounds for tackling hospital acquired infections.

To find out more, you can download the Perspective now – which is free to access for 4 weeks!

The prevalence of metal-based drugs as therapeutic or diagnostic agents: beyond platinum
Declan Gaynor and Darren M. Griffith
Dalton Trans., 2012
DOI: 10.1039/C2DT31601C, Perspective

Also of interest…

Mn(II) complexes of novel hexadentate AAZTA-like chelators: a solution thermodynamics and relaxometric study
Lorenzo Tei, Giuseppe Gugliotta, Marianna Fekete, Ferenc K. Kálmán and Mauro Botta
Dalton Trans., 2011, 40, 2025-2032
DOI: 10.1039/C0DT01114B, Paper

Metallic radionuclides in the development of diagnostic and therapeutic radiopharmaceuticals
Sibaprasad Bhattacharyya and Manish Dixit
Dalton Trans., 2011, 40, 6112-6128
DOI: 10.1039/C1DT10379B, Perspective
From themed issue Radiopharmaceuticals for imaging and therapy

The status of platinum anticancer drugs in the clinic and in clinical trials
Nial J. Wheate, Shonagh Walker, Gemma E. Craig and Rabbab Oun
Dalton Trans., 2010, 39, 8113-8127
DOI: 10.1039/C0DT00292E, Perspective

Are you following us on Twitter? @DaltonTrans

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Ball milling oxides

09 Aug 2012

Mechanochemistry has been used for centuries – according to some, as early as 371 B.C. The pestle and mortar still has a place in many chemistry labs but nowadays mechanically-induced chemistry is performed with the help of a high-energy ball mill.

In their latest Dalton Transactions Perspective, Vladimir Šepelák, Sylvie Bégin-Colin and Gérard Le Caër describe how ball milling is used to effect transformations in oxides. Whilst understanding of the mechanochemical processes involved in ball-milling metalllic compounds is growing, for the more-complex oxide materials, the field is still relatively immature.

The authors explain the various uses of ball milling oxides which can be grouped into either homogeneous or heterogeneous processes (determined by whether there is a net exchange of atoms across boundaries or not). Homogeneous processes encompass polymorphic transformations and titania phase transformations; heterogeneous processes involve compound formations, decompositions and redox reactions.

To read more about the interesting nanocrystalline characteristics that ball milling offers, read the Perspective article now.

Transformations in oxides induced by high-energy ball-milling
Vladimir Šepelák, Sylvie Bégin-Colin and Gérard Le Caër

Interested in other mechanochemistry articles? Read the growing number of articles being added to the ChemComm web theme in mechanochemistry – guest edited by Stuart James and Tomislav Friščić.

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Dalton Transactions Blog

Posts Tagged ‘Dalton’

Ligand Effects on the Catalytic Activity of Ruthenium Nanoparticles

No stone left unturned at Dalton Discussion 13

New Routes to Versatile Thorium(IV) Precursors

Top ten most accessed articles in July

The first Gold for Gold article has been published!

From double-decker to quintuple-decker: single-molecule magnetic behaviour and f-f interactions

Organometallics in catalysis: an article collection

Versatile Copper Ensemble for Cyanide Detection

Inspiring inorganic chemists to make their mark in medicine

Ball milling oxides

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