Posts Tagged ‘Dalton’

Bimetallic tuneable MOFs – a one-pot wonder

Laurance Beauvais and colleagues have synthesised a mixed metal MOF allowing different divalent metal ions to be easily incorporated into the framework. A bimetallic approach means that one metal can be used for structural integrity, whilst the other can be functional, for application in catalysis for example. The team chose a porprhyrin-based ligand to underpin the framework since this has two distinct metal binding sites – a structural metal binding site at the carboxy and pyridyl ligands; and a functional metal binding site within the porphyrin cavity.

mixed metal porphyrin

By adding the metals together in a one-pot reaction, the porphyrin framework incorporates both metals with the larger metal ions occupying the structural sites.

With the synthetic method now done and dusted, the team will now look into the catalytic and luminescent properties of these coordination framework materials.

Read Beauvais’ HOT article now… A heterometallic metal-organic framework with tuneable reactive metal sites: synthesis, characterization, and reactivity
Nathan C. Smythe, Derek P. Butler, Curtis E. Moore, William R. McGowan, Arnold L. Rheingold and Laurance G. Beauvais

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Fixing Nitrogen

The well known Haber Bosch process converts nitrogen and hydrogen into ammonia under very harsh reaction conditions. Nitrogen fixation in biology however, takes place at ambient pressure and temperature. A long term goal of researchers has been to achieve nitrogen fixation under ambient conditions.

Whilst molybdenum- and tungsten-dinitrogen complexes containing phosphine ligands are able to reduce nitrogen to ammonia under ambient conditions (in the presence of an acid such as sulfuric acid), these complexes are unable to produce ammonia from molecular dihydrogen.

Yoshiaki Nishibayashi from the University of Tokyo has recently developed a dinitrogen-bridged dimolybdenum complex bearing tridentate PNP pincer ligand which is a diphosphine containing a nitrogen linker. The catalyst is able to produce 23 equivalents of ammonia under atmospheric pressure. A second molybdenum based catalyst, this time bearing ferrocenyl diphosphine ligands is able to produce 226 equivalents of silylamine in the presence of trimethylsilyl chloride and sodium under atmospheric pressure. A future study of the reaction mechanism of these new catalytic systems could provide more insight to guide the design of more effective catalyzed nitrogen fixation in the future.

Nishibayashi has written a comprehensive article that discusses previous work on catalysts for dinitrogen fixation and also reports his recent work on two new nitrogen fixation systems catalyzed by molybdenum-dintrogen complexes. To find out more read the Dalton Transactions Perspective article.

Yoshiaki Nishibayashi
Dalton Trans., 2012, Advance Article
DOI: 10.1039/C2DT30105A
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HOT Article: Role of Zn and Mn in Parkinson’s Disease

Model of the YPK9 proteinIn this HOT article, Zoroddu and coworkers present NMR (mono- and bi-dimensional) and EPR analysis of Zn and Mn complexation to small fragments of the Park9 gene  (a member of the P5-type ATPase family) important in Parkinson’s disease (PD).   This type of study may provide an insight into the understanding of the connection between genetic and environmental PD causes.  The group are planning further investigations, involving the role of the entire protein.

Read more for FREE until 16th April 2012 at:

Mn(II) and Zn(II) interactions with peptide fragments from Parkinson’s disease genes
Serenella Medici,  Massimiliano Peana,  Lucia Gemma Delogu and Maria Antonietta Zoroddu
Dalton Trans., 2012, 41, 4378-4388
DOI: 10.1039/C2DT12168A

The following critical review may also be of interest:

The potential application of iron chelators for the treatment of neurodegenerative diseases
Robert C. Hider,  Sourav Roy,  Yong Min Ma,  Xiao Le Kong and Jane Preston
Metallomics, 2011, 3, 239-249
DOI: 10.1039/C0MT00087F

You can also keep up to date with the latest news in inorganic chemistry by following us on twitter or signing up to our e-alert service.

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Exchanging ligands on semiconducting nanocrystals

Semiconductors are at the heart of nearly all things computerised, and with nearly all things computerised that makes semiconductors important. Semiconducting nanocrystals have become an interesting area of research because as colloidal inks they can potentially be used to easily print onto substrates to create photo-voltaic devices or a broad range of electronic devices.

CdSe nanocrystals undergoing ligand exchange and thermolysis

CdSe nanocrystals undergoing ligand exchange and thermolysis

This Hot Communication from the Brutchey group details the use of a ligand which exchanges with the capping ligand of semiconducting CdSe nanocrystals making them highly dispersible in a range of polar solvents (in DMF a stable colloid forms for > 2 weeks). Under mild conditions thermolysis transforms the surface bound ligands to thiocyanate in situ, producing nanocrystal films of CdSe(SCN). There are also indications of improved inter-particle coupling…

Nanocrystal ligand exchange with 1,2,3,4-thiatriazole-5-thiolate and its facile in situ conversion to thiocyanate
David H. Webber and Richard L. Brutchey

This Hot Article is part of our up-coming themed issue ‘New Talent Americas’, Guest Edited by Dan Mindiola and John Arnold, other articles due to be published in this special issue include:

Perceiving Molecular Themes in the Structures and Bonding of Intermetallic Phases: The Role of Hückel Theory in an Ab Initio Era
Timothy E. Stacey and Daniel Fredrickson

Splitting water with rust: hematite photoelectrochemistry
Thomas W. Hamann

A heterobimetallic metal–organic framework with tunable reactive metal sites: synthesis, characterization, and reactivity
Nathan C. Smythe, Derek P. Butler, Curtis E. Moore, William R. McGowan, Arnold L. Rheingold and Laurance G. Beauvais

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Nanocatalyst for hydrogen release

hydrogen release from the dimethlyamine-borane complexAmine borane complexes are a promising solution for storing hydrogen, particularly as we move towards a hydrogen economy. Whilst focusing on developing the dehydrogenation of such complexes (namely dimethylamine-borane), scientists from Turkey have shown that you need to think small to think big by preparing a nanoparticle catalyst for the reaction.

By adding ruthenium (III) chloride to the hydrogen storing dimethlyamine-borane complex, the team found that ruthenium nanoparticles are generated in-situ which further work to catalyse the release of hydrogen from the complex.

Nanosizing the catalyst means a higher proportion of surface atoms are available for the hydrogen-storage complex – the result is greater catalytic activity and faster hydrogen generation.

Read the HOT article now for free… Hydrogen liberation from the hydrolytic dehydrogenation of dimethylamine–borane at room temperature by using a novel ruthenium nanocatalyst
Salim Caliskan, Mehmet Zahmakiran, Feyyaz Durap and Saim Özkar

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Top ten most accessed articles in February

This month sees the following articles in Dalton Transactions that are in the top ten most accessed:-

The end of iodide? Cobalt complex redox shuttles in DSSCs 
Thomas W. Hamann  
Dalton Trans., 2012, 41, 3111-3115 DOI: 10.1039/C2DT12362B  
   
Enhanced cytotoxicity of silver complexes bearing bidentate N-heterocyclic carbene ligands 
Diana C. F. Monteiro ,  Roger M. Phillips ,  Benjamin D. Crossley ,  Jake Fielden and Charlotte E. Willans  
Dalton Trans., 2012, 41, 3720-3725 DOI: 10.1039/C2DT12399A  
   

A series of isostructural mesoporous metal–organic frameworks obtained by ion-exchange induced single-crystal to single-crystal transformation 
Qingxia Yao ,  Junliang Sun ,  Kuo Li ,  Jie Su ,  Maxim V. Peskov and Xiaodong Zou  
Dalton Trans., 2012, 41, 3953-3955 DOI: 10.1039/C2DT12088G     

Highly-connected, porous coordination polymers based on [M4(µ3-OH)2] (M = CoII and NiII) clusters: different networks, adsorption and magnetic properties 
Qing Chen ,  Wei Xue ,  Jian-Bin Lin ,  Rui-Biao Lin ,  Ming-Hua Zeng and Xiao-Ming Chen  
Dalton Trans., 2012, 41, 4199-4206 DOI: 10.1039/C2DT12022D     

Functional porphyrinic metal–organic frameworks: crystal engineering and applications 
Chao Zou and Chuan-De Wu  
Dalton Trans., 2012, 41, 3879-3888 DOI: 10.1039/C2DT11989G     

Synthesis and characterization of a new porphyrin–polyoxometalate hybrid material and investigation of its catalytic activity 
Mehdi Araghi ,  Valiollah Mirkhani ,  Majid Moghadam ,  Shahram Tangestaninejad and Iraj Mohammdpoor-Baltork  
Dalton Trans., 2012, 41, 3087-3094 DOI: 10.1039/C2DT11865C     

A copper thiolate centre for electron transfer: mononuclear vs. dinuclear complexes 
Marcello Gennari ,  Jacques Pécaut ,  Marie-Noëlle Collomb and Carole Duboc  
Dalton Trans., 2012, 41, 3130-3133 DOI: 10.1039/C2DT12355J   
 
Sequential self-assembly in metal–organic frameworks 
Brandon J. Burnett and Wonyoung Choe  
Dalton Trans., 2012, 41, 3889-3894 DOI: 10.1039/C2DT12103D  
   

Synthesis of porous aromatic framework with tuning porosity via ionothermal reaction 
Wei Wang ,  Hao Ren ,  Fuxing Sun ,  Kun Cai ,  Heping Ma ,  Jianshi Du ,  Huijun Zhao and Guangshan Zhu  
Dalton Trans., 2012, 41, 3933-3936 DOI: 10.1039/C2DT11996J     

A fluorescence “turn-on” chemodosimeter for Cu2+ in aqueous solution based on the ion promoted oxidation 
Junbo Li ,  Yang Zeng ,  Qihui Hu ,  Xianglin Yu ,  Jia Guo and Zhiquan Pan  
Dalton Trans., 2012, 41, 3623-3626 DOI: 10.1039/C2DT12497A     

Why not take a look at the articles today and blog your thoughts and comments below.

Fancy submitting an article to Dalton Transactions? Then why not submit to us today or alternatively email us your suggestions.

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Ion Uptake and Solid Solution Formation

The study of ion-mineral interactions is a fascinating topic which spans many disciplines from inorganic chemistry to geology and ancient history. The driving forces behind the interaction of an ion and a mineral are complex, and whether or not an ion becomes incorporated into the solid phase is determined by many factors.

celestite strontianite Eu3+ Cm3+ Eu Cm solid solution solid-solution

 This Hot paper by Kiel Holliday et al. looks at the coordination of Eu and Cm to investigate what role local symmetry, ligand strength and a range of other parameters have in solid solution formation in both Eu- and Cm-doped strontianite and celestite.

So what is solid solution formation dependent on and what factors influence it?

Discriminating factors affecting incorporation: comparison of the fate of Eu3+–Cm3+ in the Sr carbonate–sulfate system
Kiel Holliday, Aurélie Chagneau, Moritz Schmidt, Francis Claret, Thorsten Schäfer and Thorsten Stumpf
Journal Article
Dalton Trans., 2012, 41, 3642-3647
DOI: 10.1039/C2DT12425D

You can also keep up to date with the latest information by following us on twitter or siging up to our e-alert service.

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Superior de(hydrogenation)

As the world’s reserves of fossil fuels are fast diminishing, the need for alternative efficient fuels is increasing. Using hydrogen as an energy carrier is attractive for the future since when hydrogen fuel is used in a fuel cell to generate electricity, the only waste product is water. To realise a hydrogen economy, the barriers that need to be overcome are producing hydrogen more efficiently, hydrogen transport and a suitable means of hydrogen storage.

Finding new methods of storing hydrogen is a thriving area of research. The problem we face is that hydrogen storage at ambient pressure and temperature has been a challenge. Xingguo Li and his team are one of the few groups  to investigate Mg-Pd films with a transition metal interlayer for hydrogen storage applications. The team have used a technique called magnetron spluttering which is a surface coating technique to produce Mg-Ti-Pd trilayer films.

Mg-Ti-Pd films for hydrogen storage

Most magnesium-based materials for hydrogen storage that have been studied so far have high operating temperatures and so new systems need to be developed that operate at ambient conditions. Xingguo Li and his group have now shown that this is possible by discovering that the trilayer films could be reversibly (de)hydrogenated at ambient temperature – a great improvement on the kinetics of previous magnesium based systems for hydrogen storage.

To learn more about the role that the titanium interlayer plays in the enhancement of Mg-Pd films for hydrogen storage, read the full Dalton Transactions article:

Superior (de)hydrogenation properties of Mg-Ti-Pd trilayer films at room temperature
Gongbiao Xin, Junzhi Yang, Chongyun Wang, Jie Zheng and Xingguo Li
DOI: 10.1039/C2DT30253E

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Themed Issue: Coordination chemistry in the solid state

This themed issue Guest Edited by Russell Morris showcases the breadth of inorganic chemistry research in coordination chemistry in the solid state, from unusual synthesis to advanced applications.

You can read the Editorial for a full overview of the themed issue which includes:

Coordination chemistry in the solid state MOFs CP coordination polymersHighly oriented surface-growth and covalent dye labeling of mesoporous metal–organic
frameworks
Florian M. Hinterholzinger, Stefan Wuttke, Pascal Roy, Thomas Preuße, Andreas Schaate,
Peter Behrens, Adelheid Godt and Thomas Bein

Supramolecular isomers of metal–organic frameworks: the role of a new mixed donor
imidazolate-carboxylate tetradentate ligand
Victoria J. Richards, Stephen P. Argent, Adam Kewley, Alexander J. Blake, William Lewis and
Neil R. Champness

Hydrogen adsorption in the metal–organic frameworks Fe2(dobdc) and Fe2(O2)(dobdc)
Wendy L. Queen, Eric D. Bloch, Craig M. Brown, Matthew R. Hudson, Jarad A. Mason, Leslie
J. Murray, Anibal Javier Ramirez-Cuesta, Vanessa K. Peterson and Jeffrey R. Long

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Vapour sorption with no loss of crystallinity

A recent article from John Field and his team at the University of KwaZulu-Natal, South Africa, describes the sorption and sensing properties of a porous material with an unusual crystal structure. The platinum based material has an open framework made up from repeating 2D stacks of [Pt{4′-(Ph)trpy}(NCS)]+ cations (where trpy is 2,2′:6′,2″-terpyridine) that are stabilised by extended π-π interactions. This is somewhat different to the usual coordination compounds that are formed from metal ions linked by bridging organic molecules.

Unlike it’s parent material ([Pt(trpy)(NCS)]SbF6), this compound can reversibly sorb and desorb organic vapours with no disruption of the framework structure which the team attribute to the 4′-phenyl substituent which participates in stabilising π-π interactions with pyridines on the nearby cations.

solvent accessible voids in [Pt{4'-(Ph)trpy}(NCS)]SbF6

The solvent accessible voids in [Pt{4′-(Ph)trpy}(NCS)]SbF6

Read this HOT article now:
Sorption of small molecule vapours by single crystals of [Pt{4′-(Ph)trpy}(NCS)]SbF6 where trpy = 2,2′:6′,2′′-terpyridine: a porous material with a structure stabilised by extended π–π interactions
John S. Field, Orde Q. Munro and Bradley P. Waldron

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