Chemical Communications Blog

Stephen Rimmer and Richard England from Sheffield University, in the UK, have investigated the polymerisations of methyl methacrylate, styrene or N-isopropyl acrylamide in the presence of 1-phenyl(trimethylsiloxy)ethylene. It generates telechelic oligomers and chain end functionalized highly branched polymers, where the inclusion of a difunctional monomer also produces highly branched polymers that are free from gel.

Why not read the article today and let us know your thoughts by leaving some comments below. The article will be free to access until the 17th September.

Acid-functionalized carbon nanotubes have been decorated with rhodium nanospheres using aluminum as a sacrificial substrate. Vijayamohanan Pillai and co-workers from the National Chemical Laboratory, in India, have discovered that the resulting heterostructure has a remarkable field emission than compared to smaller values that are obtained for the nanospheres and carbon nanotubes separately. It is hoped that this material may help towards the development of futuristic field emission devices.

Want to read more? Why not take a look at the article today, published in Chemical Communications, it is free to access until the 17th September.

A team of scientists from Korea University and Seoul National University have teamed up and developed penicillamine-modified gold nanoparticles and used them to enantioselectively recognise 3,4-dihydroxyphenylalanine (DOPA).

DOPA is a precursor to the neurotransmitters dopamine, noradrenaline and adrenaline collectively known as catecholamines. Aside from its natural and essential biological role, DOPA is also used in the clinical treatment of Parkinson’s disease.

Want to know more? Jong Seung Kim, Hasuck Kim et. al.,  have published this work in Chemical Communications, which you can read and access for free until the 14th September (2010).

For the first time parahydrogen-induced polarization (PHIP) was observed in the gas phase heterogeneous hydrogenation of alkynes catalyzed by Pd(0) nanoparticles embedded in a supported ionic liquid phase. Igor Koptyug and colleagues from the International Tomography Center in Russia believe that these results could be useful for the MRI studies of the catalytic reactors operated under a continuous flow mode.

To read more, why not download the article today, which is free to access until the 14th September (2010).

An efficient stereoselective synthesis of 1-alkenylphosphonates has been developed by Gwilherm Evano and colleagues at CNRS in France. Its advantages over other methods are the starting materials, which are readliy avaiable. For example, dibromo alkene is an attractive synthetic equivalent to alkenyl bromides.

The team plan to do further studies on the applications of this method, particularly investigating its use with other nucleophiles and reaction mechanisms that are still unclear and undoubtedly more complicated than the one reported here.

 Interested to read more? Then why not read the article, which is free to access until the beginning of September!

Boronic acid sensing of saccharide is enhanced by coupling it with a catalytic reaction claim Chinese scientists.

Saccharides affect many metabolic processes in the body so monitoring their levels is important. Boronic acid sensing of saccharides relies on the interaction of boronic acid with a saccharide to form a saccharide boronate. The change in fluorescence when this happens is used as an optical signal to determine how much saccharide is present. The problem is that this change is low, so the method isn’t very sensitive. ‘We wanted to find a way of amplifying the sensing signal. Coupling catalytic reactions with classic interaction-based sensing seemed a good choice,’ explains Yun-Bao Jiang at Xiamen University.

Jiang used the Suzuki catalytic reaction, where palladium catalyses the reaction of organic halides with boronic acids to form new carbon-carbon bonds, to amplify the signal of his sensing method. Normally the Suzuki reaction is carried out at high temperature to avoid unwanted side reactions. However, Jiang used one of these room temperature side reactions, the Suzuki homocoupling reaction (where two boronic acid molecules react together) to amplify the signal of the sensing method.

Jiang first performed the Suzuki homocoupling reaction with phenylboronic acid, which rapidly formed the highly fluorescent molecule biphenyl and gave a quick increase in fluorescence emission. When Jiang repeated the reaction in the presence of saccharide, boronic acid reacted with the saccharide to form saccharide boronate, which is slower in forming biphenyl, so less fluorescence was observed. This difference between the reaction rates of phenylboronic acid and the saccharide boronate was used as the basis for sensing the level of saccharide.

James Wilson from University of Miami, US, who develops fluorescent probes for imaging biological systems says, ‘coupling a catalytic reaction to the detection scheme is an attractive way of improving sensitivity through an increased emission response’. He adds, ‘I think there is room for improvement in terms of optimising the optical output, but this is an appealing concept that could be applied to other biomolecular targets’.

‘We have just established the basic concept’, explains Jiang. He hopes that the concept will be used to develop much better sensing methods which could, for example, be applied to naked-eye detection of glucose for use in clinical tests.

To find out more, why not click here and read the article in full.

Things are hotting up for ChemComm. The high-pressure, high-temperature explosive RDX  (1,3,5-trinitrohexahydro-1,3,5-triazine) is a widely used military explosive that can be compounded with mineral jelly or polymers to form plastic explosives. Colin Pulham from the University of Edinburgh and other collaborators from around the UK have structurally characterised RDX by using a combination of diffraction techniques and successfully recovered a sample at ambient pressure. 

 This kind of information can be used by scientists to explore aspects of energetic materials (propellants and explosives) that include; sensitivity to shock, heat, and friction; chemical decomposition mechanisms; energy transfer through the solid; detonation velocities; and testing the efficacy of theoretical modelling techniques.

Would you like to read more? Why not read the ChemComm article here, which is free to access until the end of August.

Coinage metal (gold, silver, copper) complexes with a thiourea component have shown significant cytotoxicities towards cancer cells and, in particular, the gold(I) thiourea complex exhibits a potent tight-binding inhibition of the anticancer drug target thioredoxin reductase.

 Chi-Ming Che and his colleagues at the University of Hong Kong and a collaborator at CNRS, in France, have published their findings in Chemical Communications – Why not read the article here, which is also free to access until the end of August.

Can Li and his colleagues from Dalian Institute of Chemical Physics, in China, have created a desirable amphiphilic microenvironment within a nanocage that can encapsulate a ruthenium-based catalyst. This nanocage can be ten times more active than one with a hydrophobic environment, where the resulting high catalytic activity can be attributed to the increased ability of the reactants to accumulate inside the nanocage. The team believe that this is mainly due to the enhanced diffusion rates of reactants during the catalytic process.

To read more, why not access the article here, which is free for all to read until the end of August!

Herbert W. Roesky and his colleagues based at Universität Göttingen, in Germany, have discovered the first example of 1,4-disilabenzene that is room temperature stable. The compound was characterized by means of single crystal X-ray diffraction studies. Nucleus Independent Chemical Shift calculations showed that the compound also has some aromatic character.

  Would like to know more? Why not read the article here and better still it is free to access until the end of August!