Archive for October, 2012

Diphosphine ligand stabilisation of onion-like RuPt nanoparticles

The catalytic potential of metal nanoparticles is widely understood and some are already used for heterogeneous catalysis.  In a dedication to Professor Cole-Hamilton, Karine Philippot and Bruno Chaudret et al. report the synthesis and characterisation of uniquely stabilised RuPt nanoparticles.

A diphenylphospine was used to stabilise bimetallic RuPt nanoparticles, both decorating them and affecting their chemical composition.  Neither an ordered alloy nor a core-shell structure was produced; instead, as proven by scattering and spectroscopic techniques, very disordered nanoparticles with Ru cores and alloy shells were observed. The mechanism that produces such an “onion” structure is thought to involve the reaction of the diphosphine ligands with Ru at the beginning of the reaction.

The use of reactive ligands in the synthesis of bimetallic nanoparticles can modify their structure, suggesting the possibility of finely tailoring the structure and surface of such nanoparticles in the future.  These modifications have already shown promise, with CO poisoning of RuPt nanoparticles having much less of an effect on hydrogenation reactions than with analagous pure Ru examples.

To find out more about these new bimetallic nanoparticles, download this HOT article now.

On the influence of diphosphine ligands on the chemical order in small RuPt nanoparticles: combined structural and surface reactivity studies
Patricia Lara, Tuğçe Ayvalı, Marie-José Casanove, Pierre Lecante, Alvaro Mayoral, Pier-Francesco Fazzini, Karine Philippot and Bruno Chaudret

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Organic radicals in a self-assembled grid

Konstantin Shuvaev, Annie K. Powell and colleagues have designed a ligand containing the nitronyl nitroxide radical.  The ligand can self-assemble with copper(II) ions to give a [2 x 2] grid complex.

The nitronyl nitroxide radical coordinated via the oxo-atom of the N+-O- fragment in a chelating fashion and lies in the equatorial plane of the metal ion.

The nitronyl nitroxide radical coordinated via the oxo-atom of the N+-O- fragment in a chelating fashion and lies in the equatorial plane of the metal ion.

The high reactivity of organic radicals makes them difficult to use but the nitronyl nitroxide radical is one of the most stable and so can be used in the design of paramagnetic polytopic ligands as building blocks for supramolecular grids.  Most previous supramolecular grids have been made using diamagnetic ligands but the team found that being able to use a paramagnetic ligand resulted in a grid with interesting spin coupling and magnetic properties.

Read more for free at…

A self-assembled Cu(II)4 [2 × 2] grid with organic radicals
Konstantin V. Shuvaev, Stephen Sproules, J. Mikko. Rautiainen, Eric J. L. McInnes, David Collison, Christopher E. Anson and Annie K. Powell
Dalton Trans., 2012
DOI: 10.1039/C2DT31946B, Paper

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Top ten most accessed articles in September

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

Recent progress in the synthesis of inorganic nanoparticles 
C. N. R. Rao ,  H. S. S. Ramakrishna Matte ,  Rakesh Voggu and A. Govindaraj  
Dalton Trans., 2012,41, 5089-5120 DOI: 10.1039/C2DT12266A     

Naphthylhydrazone based selective and sensitive chemosensors for Cu2+ and their application in bioimaging 
Sellamuthu Anbu ,  Sankarasekaran Shanmugaraju ,  Rajendran Ravishankaran ,  Anjali A. Karande and Partha Sarathi Mukherjee  
Dalton Trans., 2012,41, 13330-13337 DOI: 10.1039/C2DT31335A     

Chelating Schiff base assisted azide-bridged Mn(ii), Ni(ii) and Cu(ii) magnetic coordination polymers 
Shi-Qiang Bai ,  Chen-Jie Fang ,  Zheng He ,  En-Qing Gao ,  Chun-Hua Yan and T. S. Andy Hor  
Dalton Trans., 2012,41, 13379-13387 DOI: 10.1039/C2DT31186K     

Synthesis of iridium and ruthenium complexes with (N,N), (N,O) and (O,O) coordinating bidentate ligands as potential anti-cancer agents 
Stephanie J. Lucas ,  Rianne M. Lord ,  Rachel L. Wilson ,  Roger M. Phillips ,  Visuvanathar Sridharan and Patrick C. McGowan  
Dalton Trans., 2012,41, 13264-13266 DOI: 10.1039/C2DT32104A     

Investigation of post-grafted groups of a porous coordination polymer and its proton conduction behavior 
Munehiro Inukai ,  Satoshi Horike ,  Daiki Umeyama ,  Yuh Hijikata and Susumu Kitagawa  
Dalton Trans., 2012,41, 13261-13263 DOI: 10.1039/C2DT31836A     

Thermally and photo-induced spin crossover behaviour in an Fe(ii) imidazolylimine complex: [FeL3](ClO4)2 
John R. Thompson ,  Rosanna J. Archer ,  Chris S. Hawes ,  Alan Ferguson ,  Alain Wattiaux ,  Corine Mathonière ,  Rodolphe Clérac and Paul E. Kruger  
Dalton Trans., 2012,41, 12720-12725 DOI: 10.1039/C2DT31776A     

Selective and colorimetric fluoride anion chemosensor based on s-tetrazines 
Yingjie Zhao ,  Yongjun Li ,  Zhihong Qin ,  Runsheng Jiang ,  Huibiao Liu and Yuliang Li  
Dalton Trans., 2012,41, 13338-13342 DOI: 10.1039/C2DT31641B    

A small-molecular europium complex with anion sensing sensitivity 
Jianwei Wang ,  Jiang Wu ,  Yanmei Chen ,  Haiping Wang ,  Yiran Li ,  Weisheng Liu ,  Hao Tian ,  Ting Zhang ,  Jun Xu and Yu Tang  
Dalton Trans., 2012,41, 12936-12941 DOI: 10.1039/C2DT31607B     

Lanthanides in molecular magnetism: so fascinating, so challenging 
Javier Luzon and Roberta Sessoli  
Dalton Trans., 2012,41, 13556-13567 DOI: 10.1039/C2DT31388J     

Assessing the ligand properties of 1,3-dimesitylbenzimidazol-2-ylidene in ruthenium-catalyzed olefin metathesis 
Yannick Borguet ,  Guillermo Zaragoza ,  Albert Demonceau and Lionel Delaude  
Dalton Trans., 2013, Advance Article DOI: 10.1039/C2DT31520C     

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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CNC pincer ligand catalyst

Scientists in Mexico and Spain have synthesised a ruthenium complex using a N-heterocyclic CNC pincer ligand.

Lutidine-derived pincer complexes are well established amongst organometallic chemists. More traditionally, the pincer ligand motif, PNX has been utilised (where P is a phosphine and X is either a phosphine or N donor ligand) but substitution of phosphines with stronger electron-donating N-heterocyclic carbenes has meant that more active catalytic species have been made for promoting hydrogenation of non-active esters. Mostly speaking, these ligands follow a CNN coordination pattern. According to the researchers, the only CNC pincer complex reported coordinates to the ruthenium centre in a mer geometry.

In their latest Dalton Transactions Communication, the team report on the synthesis of a CNC ligand which coordinates to ruthenium in an usual fac mode. They proved that the resultant complex can be used to catalyse the hydrogenation of imines by firstly deprotonating one of the ligand methylene bridges.

To read more about this development, read the full article now…

Hydrogenation of imines catalysed by ruthenium(II) complexes based on lutidine-derived CNC pincer ligands
Martín Hernández-Juárez, Mónica Vaquero, Eleuterio Álvarez, Verónica Salazar and Andrés Suárez
Dalton Trans., 2012, Advance Article

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Persistently luminescent: long lasting phosphor MOF

Novel Metal Organic Framework Showing Persistent Luminescence

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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Articles from around the world: Japan

Matsumoto Castle, Nagano Prefecture. Built in 1504 the castle's origins go back to the Sengoku period

This month we have collected together some of the excellent articles published in Dalton Transactions from Japan, all are free to download until 9th November!

You can also submit your manuscript to our Japanese Editorial Office, managed by Associate Editor Professor Masahiro Yamashita.

  Click here to see the full list of articles

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Mononuclear Pacmans

As Jason Love described in his 2009 ChemComm Feature Article, pyrrole-based macrocycles are ideal ligands for creating pre-organised metal binding sites to enable the multielectron redox chemistry so required for transforming small molecules such as O2, carbon dioxide and water.

Here in their latest Dalton Transactions article, Love and colleagues take this a step further.

The team note how their previous attempts to make mononuclear transition metal complexes with the donor ligands were unsuccessful. Despite significant efforts, they could only make bimetallic complexes – well, until now that is…

The newest set of ligands now incorporate N4¬ with either O5 or ONO donors which are separated through aryl spacers. Upon binding of a singular metal atom, the complexes fold to form a Pacman-like cleft structure. Love and colleagues expect the structure to play host to guest molecules which can benefit from metal coordination as well as hydrogen bonding interactions to the oxygen and nitrogen atom acceptors.

To read more, download the article now… 

Synthesis and structures of transition metal pacman complexes of heteroditopic Schiff-base pyrrole macrocycles
James W. Leeland, Colin Finn, Bérengère Escuyer, Hiroyuki Kawaguchi, Gary S. Nichol, Alexandra M. Z. Slawin and Jason B. Love

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Studying hydrogen activation of FLPs

Scientists from Pacific Northwest National Laboratory have investigated the mechanism of heterolytic H2 activation by frustrated lewis pairs (FLPs). To do this, they employed an unique approach of solution calorimetry and were able to obtain the enthalpies and relative rates of H2 activation.

With the exception of previous studies that partly relied on theoretical calculations, there has not been a great deal of work devoted to understanding how molecular hydrogen is activated by FLPs. Autrey and colleagues have found that H2 activation rates using such species are relatively fast considering no metals are involved. They discovered that the rate was dependent on the structure of the Lewis basic amine involved, and that diffusion of hydrogen across the gas-liquid interface is not rate limiting.

Further work is needed to extract fundamental rate constants, kinetic orders, and activation barriers, say the researchers.

Read the article now to find out more…
A thermodynamic and kinetic study of the heterolytic activation of hydrogen by frustrated borane–amine Lewis pairs
Abhi Karkamkar, Kshitij Parab, Donald M. Camaioni, Doinita Neiner, Herman Cho, Thomas K. Nielsen and Tom Autrey

This article is part of an upcoming themed issue on Boranes and Borohydrides, guest edited by Simon Aldridge. Other articles by this author include:

Methods to stabilize and destabilize ammonium borohydride
Thomas K. Nielsen, Abhi Karkamkar, Mark Bowden, Flemming Besenbacher, Torben R. Jensen and Tom Autrey

Also of interest… Take a look at our recent themed issue in Frustrated Lewis Pairs

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Top ten most accessed articles in August

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

Recent progress in the synthesis of inorganic nanoparticles 
C. N. R. Rao ,  H. S. S. Ramakrishna Matte ,  Rakesh Voggu and A. Govindaraj  
Dalton Trans., 2012,41, 5089-5120 DOI: 10.1039/C2DT12266A  

Aerobic oxidation of primary alcohols catalyzed by copper complexes of 1,10-phenanthroline-derived ligands 
Oindrila Das and Tapan Kanti Paine  
Dalton Trans., 2012,41, 11476-11481 DOI: 10.1039/C2DT31134H  

First examples of two ferromagnetic end-to-end cyanate bridged 1D linear coordination polymers of nickel(ii) containing an unsymmetrical diamine 
Somnath Choubey ,  Kishalay Bhar ,  Soumi Chattopadhyay ,  Arpan Hazra ,  Tapas Kumar Maji ,  Joan Ribas and Barindra Kumar Ghosh  
Dalton Trans., 2012,41, 11551-11554 DOI: 10.1039/C2DT30429E  

Inorganic–organic hybrid compounds based on octamolybdates and multidentate N-donor ligand: syntheses, structures, photoluminescence and photocatalysis 
Wei-Qiu Kan ,  Jin Yang ,  Ying-Ying Liu and Jian-Fang Ma  
Dalton Trans., 2012,41, 11062-11073 DOI: 10.1039/C2DT30755C  

Pushing the frontiers in polyoxometalate and metal oxide cluster science 
De-Liang Long and Leroy Cronin  
Dalton Trans., 2012,41, 9815-9816 DOI: 10.1039/C2DT90121H  

A combined experimental and DFT/TDDFT investigation of structural, electronic, and pH-induced tuning of photophysical and redox properties of osmium(ii) mixed-chelates derived from imidazole-4,5-dicarboxylic acid and 2,2′-bipyridine 
Shyamal Das ,  Debasish Saha ,  Sourav Mardanya and Sujoy Baitalik  
Dalton Trans., 2012,41, 12296-12310 DOI: 10.1039/C2DT31321A  

Synthesis, structures, and magnetic properties of four copper compounds with 2,2′-dinitrobiphenyl-4,4′-dicarboxylate 
Jian-Yong Zhang ,  Xiu-Bing Li ,  Kun Wang ,  Yu Ma ,  Ai-Ling Cheng and En-Qing Gao  
Dalton Trans., 2012,41, 12192-12199 DOI: 10.1039/C2DT31378B  

Formation of stable iron/cobalt NHC complexes via unexpected ring opening and in situ generation of a tridentate ligand 
Gao-Feng Wang ,  Xiao-Jiao Song ,  Fei Chen ,  Yi-Zhi Li ,  Xue-Tai Chen and Zi-Ling Xue  
Dalton Trans., 2012,41, 10919-10922 DOI: 10.1039/C2DT30894K  

Anion-dependent construction of two hexanuclear 3d–4f complexes with a flexible Schiff base ligand 
Xiaoping Yang ,  Christopher Chan ,  Daniel Lam ,  Desmond Schipper ,  Julie M. Stanley ,  Xiaoyan Chen ,  Richard A. Jones ,  Bradley J. Holliday ,  Wai-Kwok Wong ,  Shengchun Chen and Qun Chen 
Dalton Trans., 2012,41, 11449-11453 DOI: 10.1039/C2DT31268A  

Connecting single-ion magnets through ligand dimerisation 
Po-Heng Lin ,  Ilia Korobkov ,  Tara J. Burchell and Muralee Murugesu  
Dalton Trans., 2012, Advance Article DOI: 10.1039/C2DT31226C  

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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