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Forming trifluoromethylmetallates: competition between decarboxylation and C–F bond activation of group 11 trifluoroacetate complexes, [CF3CO2ML]–
Nicole J. Rijs and Richard A. J. O’Hair
Dalton Trans., 2012, Advance Article
DOI: 10.1039/C2DT12117D
Phenanthroline-based complexes are increasingly finding use in heterogenous catalysis. One class of phenanthroline ligand is neocuproine – a dimethyl substituted derivative which Fabio Ragaini and his team have been interested in to mechanistically study the carbonylation of nitroarenes to carbamates.
When Ragaini et al. started working with the palladium neocuproine complexes, it appeared that minor variations in the synthetic procedure gave products with very different solubility properties, even though the elemental analysis data matched what was expected. In light of this, Ragaini and his team scoured the literature, upon which they discovered inconsistencies regarding the reported solubility of the [Pd(Neoc)X2] (X = Cl, Br, I) complexes.
Bearing this in mind, Ragaini et al. decided to further investigate the nature of these compounds. They discovered that for each compound in the series, two structural isomers exist: one isomer is neutral and the second is ionic. Formation of the ionic isomer occurs under a much wider range of experimental conditions than the neutral isomer. The ionic isomer must have been synthesised in previous reports even if formation of the neutral one was claimed, say the authors.
It has already been shown that the way palladium–phosphine complexes are synthesised can affect the nature of the final product, in particular its catalytic activity. Ragaini and colleagues’ paper reiterates this for nitrogen-containing ligands and highlights the importance of correctly identifying a product’s structure.
Read the Dalton Transactions article in full to find out more:
Unexpected isomerism in “[Pd(2,9-dimethylphenanthroline)X2]” (X = Cl, Br, I) complexes: a neutral and an ionic form exist
Martino Rimoldi, Fabio Ragaini, Emma Gallo, Francesco Ferretti, Piero Macchi and Nicola Casati
If you’re interested in finding out more about MOFs, and in particular those based on metalloporphyrins, then look no further… Chao Zou and Chuan-De Wu’s recent Perspective article provides an interesting overview of these functional materials. The researchers from Zhejiang University, China, discuss synthetic strategies and applications ranging from hydrogen storage to photocatalysis. Although the application of porphyrinic MOFs is considerably underdeveloped compared to other porphyrinic materials, say Zou and Wu, this article demonstrates that metalloporphyrins are an ideal choice for designing crystalline solid frameworks.
To read more, download the article now – it’s free to access.
Functional porphyrinic metal–organic frameworks: crystal engineering and applications
This Perspective article is part of the upcoming themed issue on Coordination Chemistry in the Solid State, guest edited by Dalton Transactions Associate Editor, Russell Morris. Keep your eyes peeled for many of our other coordination chemistry articles which have already been published, including Burnett and Choe’s Perspective article on “Sequential self-assembly in metal–organic frameworks”.
Edward Tiekink is based at the University of Malaya
Edward Tiekink gives us a concise overview of drug developments involving selenium and tellurium compounds in this Dalton Transactions Frontier.
Download it today, whilst it is still free….
Therapeutic potential of selenium and tellurium compounds: Opportunities yet unrealised
Edward R. T. Tiekink
Dalton Trans., 2012
DOI: 10.1039/C2DT12225A
Why not take a look at some of Edward Tiekink’s other recent articles:
The metal–carbonyl···π(aryl) interaction as a supramolecular synthon for the stabilisation of transition metal carbonyl crystal structures
Julio Zukerman-Schpector, Ionel Haiduc and Edward R.T. Tiekink
Chem. Commun., 2011, 47, 12682-12684
DOI: 10.1039/C1CC15579B, Communication
Interwoven coordination polymers sustained by tautomeric forms of the bridging ligand
Pavel Poplaukhin and Edward R. T. Tiekink
CrystEngComm, 2010, 12, 1302-1306
DOI: 10.1039/B916585A, Paper
Jie-Sheng Chen and colleagues from Shanghai Jiao Tong University report the synthesis of a Pd/Fe3O4 nanocomposite that can be used as a heterogeneous catalyst for the hydrogenation of p-nitrophenol. Convenient recycling of the catalyst using a magnet is possible – find out more by downloading the article whilst it’s free to access:
Controlled synthesis of magnetic Pd/Fe3O4 spheres via an ethylenediamine-assisted route
Hai-Qun Wang, Xiao Wei, Kai-Xue Wang and Jie-Sheng Chen
Dalton Trans., 2012
DOI: 10.1039/C2DT12278B
A team of researchers have determined the structure of metastable compound Bi2MnxAl7−xO14, an intermediate phase in the decomposition of mullite-Bi2MnxAl4-xO9+δ, using a strategy that included the use of a charge-flipping algorithm and Monte-Carlo based simulations. The strategy may be particularly useful in situations where it is difficult to get high quality crystals.
The article is currently free so download it today.
Mullite-derivative Bi2MnxAl7−xO14 (x ~ 1): structure determination by powder X-ray diffraction from a multi-phase sample
Tao Yang, Vaclav Petricek, Wei Wan, Zidong Wei and Junliang Sun
Dalton Trans., 2012
DOI: 10.1039/C2DT11855F
This Hot Article from the University of Western Ontario by Laura C. Pavelka and Kim M. Baines details some interesting cycloaddition reactions of phosphaalkenes with alkynes.
Reactions of this type have not been well studied and typically require electron rich alkynes and quite specialised phosphoalkenes for the reaction to proceed. Here the authors have developed a much simpler approach to the syntheses using readily available reagents and a more direct route, allowing them to produce a variety of 1,2-dihydrophosphinines in good yields.
To find out how, you can download their article which is free to access for the next 4 weeks
Facile synthesis of luminescent benzo-1,2-dihydrophosphinines from a phosphaalkene
Laura C. Pavelka and Kim M. Baines
Dalton Trans., 2012, Advance Article
DOI: 10.1039/C2DT11690A
To keep up to date with the latest news in inorganic chemistry you can also follow us on twitter or sign up to our e-alert service.
A team of researchers have synthesised an iron(II) bispyrazolylpyridine complex in order to elucidate the interplay between spin transition and polymorphism.
Complexes demonstrating high spin–low spin crossover could prove to be very useful materials in technologies which rely on switching mechanisms, however, to use them to their full potential, any properties affecting their performance need to be understood – crystal symmetry being one of them. Mario Ruben and co-workers discovered that crystallisation of the iron(II) bispyrazolylpyridine complex produced two polymorphs which upon heating, yields a third polymorphic form. Interestingly, the different polymorphs each demonstrate different magnetic behaviour.
Whilst one polymorph, exhibits an abrupt, hysteretic high/low spin transition, the other remains low spin. The team have attributed this to varying levels of inter-molecular cooperativity within the crystal structures.
To read more, download the Dalton Transactions article now…
The interplay of iron(II) spin transition and polymorphism
Ivan Šalitroš, Olaf Fuhr, Andreas Eichhöfer, Robert Kruk, Ján Pavlik, Lubor Dlháň, Roman Boča and Mario Ruben
Cisplatin is a well known chemotherapy drug used to treat a range of cancers. While the drug can be an effective treatment there are notable unwanted side-effects, which can include nausea, vomiting, kidney damage and loss of hearing. This new research from Leeds University by Charlotte Willans et al. details the activity of a range of silver complexes containing N-heterocyclic carbene (NHC) ligands which show comparable and even enhanced cytotoxicity compared to cisplatin. As the compounds don’t contain platinum they are likely to be less toxic and therefore exhibit fewer and less severe side-effects.
The team synthesised a series of monodentate, bidentate and macrocyclic cationic silver bis(NHC) complexes and tested their activity with cell lines of breast and colon cancer (MCF7 and DLD1 lines respectively). They found that the bidentate complexes showed enhanced cytotoxicity over the monodentate and macrocyclic ligands, which were similar to cisplatin. As yet the exact mechanisms of action are still unclear but are likely linked to the stabilities of the complexes.
For more information about this exciting research you can download the article which is free to access for 4 weeks. You can also keep up to date with all the latest news in inorganic chemistry by following us on twitter or signing up to the Dalton Transactions e-alert service.
Enhanced cytotoxicity of silver complexes bearing bidentate N-heterocyclic carbene ligands
Charlotte E. Willans, Diana C F Monteiro, Roger M Phillips, Benjamin D Crossley and Jake Fielden
Dalton Trans., 2012, Accepted Manuscript
DOI: 10.1039/C2DT12399A
Also of interest from the collection ‘Highlights in Chemistry’
Therapeutic applications of gold complexes: lipophilic gold(III) cations and gold(I) complexes for anti-cancer treatment
Chi-Ming Che and Raymond Wai-Yin Sun
Chem. Commun., 2011, 47, 9554-9560
DOI: 10.1039/C1CC10860C, Highlight
We are pleased to invite you to ISBOMC12 which will be held at the Scarborough campus of the University of Toronto in Toronto, Canada. UTSC is one of the three sister campuses making up the University of Toronto (St. George, Scarborough and Mississauga). The conference covers all aspects of bioorganometallic chemistry and includes lectures from these keynote speakers.
Kay Severin
Shunsaku Kimura
Takashi Hayashi
Bernhard K. Keppler
Rudolf K. Thauer
Peter Sadler
There is still time to register and submit an abstract; the deadline is March 31, so hurry!
