Dalton Transactions Blog

Posted on behalf of Ian Mallov, web writer for Dalton Transactions

The water oxidation reaction is one of the most fundamental in chemistry and likely to be one of the first students are introduced to. During the reaction, water and energy are combined to give oxygen gas, protons and electrons, with the latter used to reduce the protons and yield hydrogen gas. The storage of hydrogen gas is one proposed method of storing the energy generated from renewable sources as, by burning the hydrogen and regenerating water in the process, you can release and harness the energy as needed.

In order for the water oxidation cycle to result in a net energy gain, a catalyst is needed for the oxidation process, with the majority of current systems incorporating rare or expensive metals. In their recent Dalton Transactions article, Johnsson and co-workers used small, cluster compounds made of cobalt, selenium, oxygen and chlorine to catalyze water oxidation. Two of the compounds, Co₄(SeO₃)₃Cl₂ and Co₃Se₄O₁₀Cl₂, were previously unreported but are closely related to the third, known compound Co₅Se₄O₁₂Cl₂. To synthesise the molecules, the authors heated mixtures of CoO, SeO₂, and CoCl₂ to 550 °C in a furnace for a number of days, with different ratios of the starting materials used to produce the different compounds. Adding each compounds to a solution of phosphate buffer and Ru(bpy)₃(PF₆)₃ led to the evolution of oxygen gas, which, by further ¹⁸O labelling experiments, was confirmed to occur due to water oxidation. 

Catalytic oxygen evolution by cobalt catalysts

Analysis of a catalyst intended to facilitate sustainable energy storage should spur discussion of the environmental impact of making the catalyst.  The large energy input to heat the materials is a drawback.  But, if synthesized in good yield in solid-state (solventless) reactions, as done here, the reactions would score well on the E-factor scale, a metric measuring waste produced per mass of product that gives a more complete indication of material efficiency than the obsolete atom economy principle. 

Though the catalytic activity proved wanting, the simple compounds and syntheses here present an interesting strategy towards useful water oxidation catalysis. 

Find out more and download the article now:
Cobalt selenium oxohalides: Catalysts for Water Oxidation
Dalton Trans., 2013, DOI: 10.1039/C3DT53452A

Ian Mallov is currently a Ph.D. student in Professor Doug Stephan’s group at the University of Toronto. His research is focused on synthesizing new Lewis-acidic compounds active in Frustrated Lewis Pair chemistry. He grew up in Truro, Nova Scotia and graduated from Dalhousie University and the University of Ottawa, and worked in chemical analysis in industry for three years before returning to grad school.

Bacterial resistance to standard types of antibiotics is a growing problem in medical science. The most famous example is MRSA, which stands for Methicillin-resistant Staphylococcus aureus. This name refers to a bacterium which, through the process of natural selection, is now resistant to a class of antibiotics called beta-lactams (which include penicillin and the cephalosporins). MRSA is especially dangerous in environments like hospitals and nursing homes, where patients or residents with weakened immune systems are at greater risk of infection (compared with the general public). The Office for National Statistics reports that between 1993 and 2005, the number of deaths associated with MRSA rose from 51 to 1,652.¹

Methods to try and fight this growing threat include increased sanitization of areas where people are most at risk of infection and screening patients for the bacteria upon hospital admission and separating carriers from non-carriers. In the scientific community, development of new compounds which are capable of killing MRSA and other antibiotic resistant bacteria is a highly important, ongoing research area.²

Metal complexes displaying biological activity have been widely reported; in particular complexes containing the metal ruthenium have been shown to display anti-cancer, anti-microbial and DNA binding abilities.³ In this paper, the authors synthesise several new ruthenium complexes and perform tests to assess their anti-microbial activity against MRSA.

Structure of ruthenium complexes synthesized

A ‘zone of clearance’ study pitted two of the new ruthenium complexes against methicillin in a test of how effectively each compound inhibited bacterial growth (see below). The ruthenium complexes were shown to have superior anti-MRSA activity when compared with methicillin, suggesting they could provide prolonged antibacterial activity when used as topical antibiotics.

‘Zone of clearance’ assay results

To read more, download the article now:
“Development of ruthenium(II) complexes as topical antibiotics against methicillin resistant Staphylococcus aureus”
W.-Y. Wong et al., Dalton Trans. 2014, DOI:10.1039/C3DT52879K

References:

¹ UK Office for National Statistics, www.ons.gov.uk
² P. A. Ashford, S. P. Bew, Chem. Soc. Rev., 2012, 41, 957
³ C. S. Allardyce, P. J. Dyson, Platinum Metals Rev., 2001, 45, 62

Dr C. Liana Allen is currently a post-doctoral research associate in the group of Professor Scott Miller at Yale University, where she works on controlling the enantio- or regioselectivity of reactions using small peptide catalysts. Liana received her Ph.D. in organic chemistry at Bath University with Professor Jonathan Williams, where she worked on developing novel, efficient syntheses of amide bonds.

Posted on behalf of Jamie Humphrey, Editor

Our number one priority at Dalton Transactions is to ensure that the journal continues to support our community by providing excellent services for authors and by publishing only the best inorganic chemistry research. We strive to develop and innovate to make sure that the journal continues to serve the international inorganic community. This is very much at the heart of everything we do.

The truly international nature of the journal is represented not only in our authorship (we published articles from 70 countries in 2012), but also through the Editorial Board membership, including our team of Associate Editors – about half of the papers submitted to the journal are handled by this team, with the rest handled by the team of Editors based in Cambridge. Our Associate Editors span the globe, with editorial offices in the USA, UK, Germany, China and Japan. The Royal Society of Chemistry has also been developing its international staff presence in recent years and we now have editorial staff based in Japan, China and the USA, in addition to Royal Society of Chemistry offices in India, Africa and, more recently, Brazil.

In today’s information age, where we can sometimes feel overwhelmed with the amount of information that is available, access to reliable trustworthy knowledge has never been more important. At Dalton Transactions, our fair and impartial peer-review means the content we publish is always of the highest possible quality. Ensuring your research gets the right audience is also key. We have therefore introduced initiatives to lead to greater discoverability for articles published in the journal, and to develop additional measures of an article’s impact.

Dalton Transactions is part of a pilot programme between the Royal Society of Chemistry and Kudos, which aims to provide tools and services to help researchers maximise the usage and impact of their articles. The need for Kudos arises from developments in global academic and research policies that see evolving measures of ‘impact’ used to assess excellence. Kudos aims to provide a service to help researchers and their institutions measure, monitor and maximize the usage of and citations to their articles. The Royal Society of Chemistry also recently introduced a new system for monitoring article-level metrics in Dalton Transactions. The service collates online “mentions” of scholarly articles from social media, newspapers, blogs and other sources into a report that appears online with the article to showcase its uptake, visibility and societal impact. Article-level metrics represents a shift from measuring the impact of a journal to the impact of an article.

Supporting the community is at the heart of Dalton Transactions and is also at the core of the Royal Society of Chemistry, the world’s leading chemistry community. One way in which we supported chemists across the globe is through the funding of the International Year of Chemistry legacy grants. In 2012, over 60 of our member groups received grants each of £1000 to arrange events and activities to promote the chemical sciences. These had an international nature, and ranged from workshops for migrant children in Beijing and a science fair on water chemistry in southern India to supporting chemistry education in tsunami-affected areas in Sri Lanka. Learn more about these grants via www.rsc.org/scienceandtechnology/funding/iyclegacygrants.asp

Dalton Transactions continues to publish research from all areas of inorganic, organometallic and bioinorganic chemistry. Our Themed Issues bring together the best articles in topical research areas or highlight emerging subjects. Table 1 gives full details of the Themed Issues published in 2013.

Table 1 Dalton Transactions Themed Issues published in 2013

Themed Issues planned for 2014 include Carboranes (Guest Editors: Professor Guo-Xin Jin, Fudan University, China and Professor Zuowei Xie, The Chinese University of Hong Kong, Hong Kong), Inorganic Chemistry for Renewable Energy Conversion and Storage (Guest Editor, Professor Lars Kloo, KTH, Sweden), Layered Inorganic Solids (Guest Editors: Professor Russell Morris, University of St. Andrews, UK, Dr Jiri Cejka, J. Heyrovsky Institute of Physical Chemistry, Hungary, Dr Petr Nachtigall, Charles University, Czech Republic, Dr Wieslaw Roth, Jagiellonian University of Krakow, Poland), New Talent: Europe (Guest Editors, Professor Dr Matthias Tamm, Technische Universität Braunschweig, Germany and Dr Marc D. Walter, Technische Universität Braunschweig, Germany), Organometallic and Coordination Derivatives of Nanocarbons (Guest Editors, Professor Andrei Khlobystov, University of Nottingham, UK and Professor Andreas Hirsch, University Erlangen-Nuremberg, Germany), New Expeditions in Polar Organometallic Chemistry (Guest Editor, Professor Eva Hevia, University of Strathclyde, UK), Spectroscopy of Inorganic Excited States (Guest Editor, Dr Julia Weinstein, University of Sheffield, UK) and Synergy between Experiment and Theory (Guest Editor, Professor Eric Clot, University of Montpellier, France).

2014 will be a busy year for inorganic chemistry conferences, and I hope that you will look out for me or Deputy Editor Fiona McKenzie – we would love to meet up with you! Two such meetings are the Dalton Discussions, which will take place in the UK. We are proud to publish the presented papers in Dalton Transactions. The titles of the 2014 meetings are ‘Advancing the Chemistry of the f-elements: Dalton Discussion 14’ (28–30 July 2014 Edinburgh, UK) and ‘Metal ions in medical imaging: optical, radiopharmaceutical and MRI contrast: Dalton Discussion 15’ (8–10 September 2014, York, UK). Another important inorganic meeting organised by the Royal Society of Chemistry in 2014 is the 13^th ISACS meeting (Challenges in Inorganic and Materials Chemistry (ISACS13)) which will take place in Dublin, Ireland, 1–4 July 2014. To discover which conferences the Editorial Team will be attending in 2014, follow us on twitter (@DaltonTrans and @humphreyj).

We were pleased to support a number of international conferences in 2013 through sponsorship – you may even have attended one of our sponsored lectures. We give support to younger members of the community via poster prizes, and in 2013 we awarded 22 poster prizes, celebrating the achievements of members of our community in the early years of their academic careers. If you are organising a conference in 2014 and you would like us to sponsor a poster prize, please let us know.

With a thriving worldwide network, and a not-for-profit ethos, the Royal Society of Chemistry is the best place to publish work that advances excellence in the chemical sciences. Publish with Dalton Transactions and you’ll be supporting the wider scientific community and future generations of chemists and chemical scientists.

Have a fantastic 2014!

Download the PDF here

We are pleased to announce the inclusion of Altmetrics on Dalton Transactions.

With a constantly changing publishing landscape and changes to the way people use scientific literature, altmetrics is a measure that can monitor the level of conversation and interest in a particular piece of research at the article level. Thus altmetrics provides an additional modern metric for our authors to measure the impact of their work, rather than rely solely on citations and impact factor.

To view the altmetrics on Dalton Transactions articles, use the Metrics tab as pictured below on the article landing page.

A press release from Altmetrics is available on our website.

What do you think? We are interested to hear your feedback on this new development and how you are utilising these new types of metrics. Please leave your comments below.

Posted on behalf of Ian Mallov, web writer for Dalton Transactions

We often invoke the analogy of using building blocks when we talk about constructing large, complex molecules.  Adding small building blocks often allows for finer control in design, and diatomic hydrogen is the most used small building block.

To add hydrogen to other molecules, hydrogen molecules themselves are split into a proton and hydride; these are then transferred to the target molecule.  Recently, main group compounds involving frustrated Lewis pairs have been used in both steps instead of transition metal catalysts.  There are also a few main group molecules where hydrogen is split at a single atomic site.  Silylenes – the silicon analogue of carbenes, and the subject of this paper, with two bonds, a pair of electrons, and an empty p-orbital, are one type of these select few. This paper mentions the argument that non-transition metal catalysts may be “greener,” but a thorough life-cycle analysis of extraction, reaction and disposal would be necessary to indicate this. 

Authors, Kuriakose and Vanka use Density Functional Theory to explore the question of why some silylenes split hydrogen and some don’t.  Specifically, they want to test the hypothesis that whether or not hydrogen is split at the silicon centre depends on if an adjacent atom “interferes,” leading to undesired products.  They create a profile of the energies of reaction (with hydrogen gas) of three distinct types of silylene: a boryl amido silylene (I), a silyl amido silylene (II) and a dithiolate silylene (III).  I and II have activated hydrogen, while III hasn’t been observed to do so. 

The free energy profiles for the reaction of silylene, III, with hydrogen  

After optimizing geometry they model the HOMO and LUMO of the silylenes, since donation of electrons from the HOMO and acceptance of electrons into the LUMO are necessary for hydrogen activation.  In the case of I and II, the LUMO is localized on the silicon atom, while in III, it is not. Correspondingly, the reaction pathway of splitting hydrogen is energetically favoured for I and II, and disfavoured for III.  They also examine effects of other features, such as the angle of the two substituents. 

Have a read of the full article now:

New insights into small molecule activation by acyclic silylenes: a computational investigation
Nishamol Kuriakose and Kumar Vanka
Dalton Transactions, DOI: 10.1039/c3dt52817k

Ian Mallov is currently a Ph.D. student in Professor Doug Stephan’s group at the University of Toronto. His research is focused on synthesizing new Lewis-acidic compounds active in Frustrated Lewis Pair chemistry. He grew up in Truro, Nova Scotia and graduated from Dalhousie University and the University of Ottawa, and worked in chemical analysis in industry for three years before returning to grad school.

Posted on behalf of Liana Allen, web writer for Dalton Transactions

As more information becomes known about the negative impacts that humans are having on the Earth’s environment, increasing focus is being put on ways of decreasing these effects in all aspects of our lives. For the chemical industry, there are already several key areas which have been identified as needing particular attention with respect to decreasing our effect on the environment. In the last decade, this challenge has become so important that it is now recognized as a field in its own right, referred to as ‘Green Chemistry’. Some of the overall themes of green chemistry are: decrease of the amount of waste by-products generated by a reaction (i.e. avoiding poor atom economy reagents), reduction of reagents which pose safety hazards (i.e. explosives and known toxic compounds), and ‘cleaner’ solvent choices (i.e. avoiding chlorinated solvents, or volatile solvents whose vapours pose an environmental problem).¹

One of the most important reactions used in chemical industry is formation of carbon-carbon bonds.² The methodology most commonly used to form such bonds is a group of reactions called palladium-catalysed cross-couplings. One of this set of vital reactions is called the Sonogashira coupling. This reaction is used to couple terminal alkynes with aryl or vinyl halides to form di-substituted alkynes, and requires a copper co-catalyst (in addition to a palladium catalyst), heating conditions, and a solvent such as DMF.

In their recent Dalton Transactions article, Wang and colleagues take significant steps towards applying the principles of green chemistry to the Sonogashira reaction by optimizing new conditions where; (a) a copper co-catalyst is not required, thus increasing the atom efficiency of the reaction, (b) the reaction can be run at room temperature, eradicating the energy cost normally required for heating and (c) the solvent is readily available and environmentally benign water.

To read more, see:

Copper-free Sonogashira Cross-Coupling Reaction Promoted by Palladium complexes of Nitrogen-containing Chelating Ligand in Neat Water at Room Temperature
Hong Zhong, Jinyun Wang, Liuyi Li and Ruiha Wang, Dalton Trans. 2013, DOI:10.1039/C3DT52970C

Dr C. Liana Allen is currently a post-doctoral research associate in the group of Professor Scott Miller at Yale University, where she works on controlling the enantio- or regioselectivity of reactions using small peptide catalysts. Liana received her Ph.D. in organic chemistry at Bath University with Professor Jonathan Williams, where she worked on developing novel, efficient syntheses of amide bonds.