The surprising chemistry of the noble gases

18 Dec 2012

Victoria Wilton is a guest web-writer for PCCP. She is currently studying for a PhD at the University of Nottingham, UK.

The inherent lack of reactivity of the noble gases is so entrenched in the collective mind of the population, that even though noble gas containing compounds have been known for decades, the identification of new ones is still extremely exciting. I was therefore delighted to come across this particular article in PCCP.

Fernández and Frenking conducted a theoretical investigation into the stability and nature of the bonding involved in two classes of compounds containing a Xe-Xe bond. No species from either of the two groups, HXeXeX (where X=halogen) and RXeXeR’ (where R and R’ are both halogens), have ever been observed experimentally, and based on their results, several compounds for which this might be possible were identified.

The strong correlation observed between Xe-Xe bond length and the energy barrier to decomposition suggests that the strength of this bond plays a vital role in the stability of the molecule. Both of these characteristics were shown to decrease with increasing halogen mass, and generally indicated stronger bonding and greater stability in the RXeXeR’ molecules compared with HXeXeX. On this basis, HXeXeF and FXeXeF were proposed as the most viable compounds for experimental isolation.

The former was shown to be the result of two electrostatically bonded fragments, HXeXe⁺ ^–F, with a strong covalent H-Xe bond. The positive charge is shared over the two Xe atoms, with the smaller proportion on the Xe next to the F atom. The Xe-Xe bond in this case is thought to be primarily electrostatic, and involve only the p_x orbital. By analogy, FXeXeF could either be formed of similar electrostatically bonded fragments, or through the interaction of two FXe· radicals. The calculations pointed to contributions from both mechanisms, with a small but significant bias toward radical interaction.

This research represents another step in unravelling and understanding the complicated and often surprising chemistry of the noble gases. It would therefore be marvellous to see experimental confirmation of their findings in the future.

By Victoria Wilton

Read the full details of this fascinating article which was published as part of the PCCP themed issue on Predicting new molecules by quantum chemical methods:

Neutral noble gas compounds exhibiting a Xe–Xe bond: structure, stability and bonding situation
Israel Fernández and Gernot Frenking
DOI: 10.1039/C2CP41244F

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New PCCP Associate Editor Prof. Gaoquan Shi

18 Dec 2012

By Rowan Frame, Commissioning Editor.

We are delighted to welcome Professor Gaoquan Shi as a new Associate Editor for Physical Chemistry Chemical Physics (PCCP). His research interests are focused on functional polymers, especially the syntheses and applications of conducting polymers and carbon nanomaterials.

Professor Shi has been a professor of Chemistry at Tsinghua University since 2000. In 2004, he received the 2nd grade award of Natural Science of China and the youth knowledge innovation prize of Chinese Chemical Society and BASF Company.

Professor Shi will start handling papers soon and so we encourage you to submit to his editorial office.

Read some of Professor Shi’s recent articles in PCCP:

Synthesis of gold@carbon dots composite nanoparticles for surface enhanced Raman scattering
Peihui Luo, Chun Li and Gaoquan Shi
DOI: 10.1039/C2CP40767A

Supercapacitors based on self-assembled graphene organogel
Yiqing Sun, Qiong Wu and Gaoquan Shi
DOI: 10.1039/C1CP22409C

High-performance supercapacitor electrodes based on graphene hydrogels modified with 2-aminoanthraquinone moieties
Qiong Wu, Yiqing Sun, Hua Bai and Gaoquan Shi
DOI: 10.1039/C1CP20980A

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Understanding the interaction of C60 with red blood cells to guide therapeutic use of nanomaterials

14 Dec 2012

By Heather Montgomery, Deputy Editor.

Carbon nanomaterials have been hailed as potential drug carriers and biosensors, so it is important to understand how they interact with human cells. Scientists in China have studied the interaction of C₆₀ nanoparticles (NPs) with human red blood cells and found that they made the cell membrane become “softer and easier to break”. They were able to successful model this, and predict the effect of a given amount of NPs. The finding could be used to determine appropriate dosage levels of C₆₀ NPs in medical applications for maximum therapeutic effect with the minimum toxicity.

Read more about this fascinating work in this HOT PCCP article:

Mechanical characteristics of human red blood cell membrane changing due to C₆₀ nanoparticles infiltration
Yue Zheng
DOI: 10.1039/C2CP42850D

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PCCP themed issue: Superresolution imaging and fabrication with light

07 Dec 2012

By Heather Montgomery, Deputy Editor.

Superresolution imaging and fabrication with light
Guest Editors: Françisco M. Raymo (University of Miami, USA)

PCCP is delighted to announce the high-profile themed issue ‘Superresolution imaging and fabrication with light’. It is our pleasure to invite you to submit to this themed issue.

The themed issue will be published in PCCP in 2013 and will be promoted to the community throughout the year to maximise the visibility of the work published.

Deadline for Submissions: 8 April 2013

Diffraction prevents the focusing of light within volumes of subwavelength dimensions. As a result, this unavoidable physical phenomenon limits the resolution of imaging and lithographic techniques based on far-field optics. In order to overcome these stringent limitations, significant research efforts have been directed, over the past decade, to the identification of protocols to overcome diffraction.

Some of these methods rely on the photochemical and photophysical properties of engineered chromophores to circumvent diffraction. These clever operating principles have already succeeded in bringing the resolution of fluorescence imaging and photolithography down to the nanoscale. Indeed, they are starting to impact biomedical research and, presumably, will soon have similar implications in information technology.

Thus it is timely to publish a themed collection in PCCP on this emerging and extremely promising area of research. The themed collection will provide a general overview of the fundamental principles of these strategies as well as covering optical imaging and fabrication at the nanoscale.

It is essential that all submissions to PCCP should contain new physical insight and contributions to this themed collection will be assessed on this basis.

Manuscripts can be submitted in any reasonable format using our online submissions service
Submissions should be high quality manuscripts of original, unpublished research
Communications and full papers can be submitted for consideration, which will be subject to rigorous peer review
Please indicate upon submission that your manuscript is intended for this themed is intended for the themed issue

Please contact the PCCP Editorial Office to let us know you plan to contribute an article.

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Physical-chemistry at the cross-road of advanced oxide materials

21 Nov 2012

By Heather Montgomery, Deputy Editor.

PCCP themed issue: call for papers

Physical-chemistry at the cross-road of advanced oxide materials
Guest Editors: Flora Boccuzzi (University of Torino), Leonardo Marchese (University of Piemonte Orientale “A. Avogadro”) and Gianmario Martra (University of Torino)

PCCP is delighted to announce the high-profile themed issue on advanced oxide materials. It is our pleasure to invite you to submit to this themed issue.

The themed issue will be published in PCCP in 2013 and will be promoted to the community throughout the year to maximise the visibility of the work published.

Deadline for Submissions: 18 March 2013

Oxide-based materials have been largely studied for their catalytic, electronic or adsorbent properties. Since the early 1960’s, when studies of high surface area oxides and metal dispersed on oxides of interest for catalysis and sensing were mostly developed, their interest has been extended along the years to other technological applications such as energy production, biotechnology and nanomedicine. In general, the broad range of emerging applications has pushed the preparation of new functional oxide-based materials, with expected tailored smart properties.

This themed issue is intended to highlight the central role of experimental and theoretical physical-chemical investigations of bulk and surface structural and functional properties of these materials to target actual, knowledge-based breakthroughs.

Topics covered by this themed issue include experimental and/or theoretical studies of:

structure of surface sites of heterogeneous catalysts by in-situ/in-operando methods;
mechanisms of reactions of interest for sustainable chemical processes and catalyzed by oxide-based materials;
molecular or photophysical events occurring at the surface/interface of nanomaterials for energy production;
understanding physico-chemical phenomena of oxide-based materials for energy production, storage and emission;
physico-chemical characterization of functional-oriented materials for sensing;
physico-chemical studies of the interaction of oxide-based materials with biomolecules;
unconventional spectroscopic studies.

Contributions on oxide-based materials outside the above list of topics will be also accepted provided that they are within the scope of PCCP and contain sufficient new physical insight.

Manuscripts can be submitted in any reasonable format using our online submissions service
Submissions should be high quality manuscripts of original, unpublished research
Communications and full papers can be submitted for consideration, which will be subject to rigorous peer review
Please indicate upon submission that your manuscript is intended for this themed is intended for the themed issue

Please contact the PCCP Editorial Office to let us know you plan to contribute an article.

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Understanding bonding in new inorganic clusters

20 Nov 2012

By Heather Montgomery, Deputy Editor.

A paper from the recent PCCP themed issue on Predicting new molecules by quantum chemical methods has been highlighted in UCLA today. The article by Anastassia Alexandrova and her coworkers was featured on the back cover of the issue and describes the authors work on using computational methods to discover new inorganic clusters and understand their bonding.

Read this interesting PCCP paper today:

Selected AB₄^2−/− (A = C, Si, Ge; B = Al, Ga, In) ions: a battle between covalency and aromaticity, and prediction of square planar Si in SiIn₄^2−/−

Anastassia N. Alexandrova , Michael J. Nayhouse , Mioy T. Huynh , Jonathan L. Kuo , Arek V. Melkonian , Gerardo Chavez , Nina M. Hernando , Matthew D. Kowal and Chi-Ping Liu

Phys. Chem. Chem. Phys., 2012, 14, 14815-14821

DOI: 10.1039/C2CP41821E

Selected AB₄^2−/− (A = C, Si, Ge; B = Al, Ga, In) ions: a battle between covalency and aromaticity, and prediction of square planar Si in SiIn₄^2−/−
Anastassia N. Alexandrova, Michael J. Nayhouse, Mioy T. Huynh, Jonathan L. Kuo, Arek V. Melkonian, Gerardo Chavez, Nina M. Hernando, Matthew D. Kowal and Chi-Ping Liu
DOI: 10.1039/C2CP41821E

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Combined theoretical and experimental approach identifies ideal nerve gas capture agent

09 Nov 2012

By Heather Montgomery, Deputy Editor.

Scientists working in Australia, Poland and the USA have come up with a combined theoretical and experimental approach for screening candidate materials that could be used to capture nerve gas agents. They conclude that the ideal material contains slit-shaped pores of around 0.5 nm width.

Their PCCP paper was highlighted on the nanowerk website. Read the article today:

Screening of Carbonaceous Nanoporous Materials for Capture of Nerve Agents
Piotr Kowalczyk, Artur Piotr Terzyk, Piotr A. Gauden and Alexander V Neimark
DOI: 10.1039/C2CP43366D

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Dreaming of new and unusual molecules

09 Nov 2012

By Heather Montgomery, Deputy Editor.

Table of contents image In this fascinating PCCP Perspective Alexander Ivanov and Alexander Boldyrev describe progress in using theoretical methods to predict unusual new molecules that can potentially be made for real in the experimental lab.

They suggest that emerging methods for predicting exciting materials and clusters will allow the field to develop in new directions in the coming years.

Read this PCCP Perspective article in full today:

Reliable predictions of unusual molecules
Alexander S. Ivanov and Alexander I. Boldyrev
DOI: 10.1039/C2CP42877F

If you enjoyed this article you may also be interested in our recent themed issue on Predicting new molecules by quantum chemical methods, Guest Edited by Gabriel Merino and Thomas Heine.

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New finding throws doubt on interpretation of single molecule fluorescence imaging data

09 Nov 2012

By Heather Montgomery, Deputy Editor.

Single molecule fluorescence measurements hold great promise for studying biological processes on a very small scale. These experiments are typically conducted using a scanning confocal fluorescence microscope.

The data rely on the focusing of excitation light to a specific point on a molecule, with the fluorescence output being collected using the same objective lens. The fluorescence output can be varied by changing the external electric field. But an out-of-focus excitation light, say scientists in Singapore, due to the not uncommon occurrence of damage to the type of thin film devices used in such experiments, can result in a decrease in the output fluorescence – which could potentially be misinterpreted as a significant effect.

The results indicate that researchers measuring fluorescence modulation using this electric field method should be aware that this type of artefact could interfere with their results.

Read more details about these interesting findings:

Other origins for the fluorescence modulation of single dye molecules in open-circuit and short-circuit devices
Edwin Yeow, Jefri Sanusi Teguh, Michael Kurniawan, Xiangyang Wu and Tze Chien Sum
DOI: 10.1039/C2CP43284F

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New theoretical method to model anisotropy in weak magnetically coupled systems

05 Nov 2012

By Heather Montgomery, Deputy Editor.

Scientists in France and Germany have come up with a method to model the electronic and magnetic properties of polynuclear complexes. Electron paramagnetic resonance (EPR) spectroscopy is used to measure magnetic anisotropy, but in weakly coupled systems, the signal can be very complicated or absent altogether.

Older methods using a spin ladder approach were only accurate at the lowest temperatures. The new method allowed the team to interpret complex experimental EPR data at various temperatures.

Such complexes are important in molecular magnets and are found in nature, so their study is of wide interest.

Read this HOT PCCP article today:

A combined high-field EPR and quantum chemical study on a weakly ferromagnetically coupled dinuclear Mn(III) complex. A complete analysis of the EPR spectrum beyond the strong coupling limit.
Marius Retegan, Marie-Noëlle Collomb, Frank Neese and Carole Duboc
DOI: 10.1039/C2CP42955A

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PCCP Blog

The surprising chemistry of the noble gases

New PCCP Associate Editor Prof. Gaoquan Shi

Understanding the interaction of C60 with red blood cells to guide therapeutic use of nanomaterials

PCCP themed issue: Superresolution imaging and fabrication with light

Physical-chemistry at the cross-road of advanced oxide materials

Understanding bonding in new inorganic clusters

Selected AB₄^2−/− (A = C, Si, Ge; B = Al, Ga, In) ions: a battle between covalency and aromaticity, and prediction of square planar Si in SiIn₄^2−/−

Combined theoretical and experimental approach identifies ideal nerve gas capture agent

Dreaming of new and unusual molecules

New finding throws doubt on interpretation of single molecule fluorescence imaging data

New theoretical method to model anisotropy in weak magnetically coupled systems

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Selected AB42−/− (A = C, Si, Ge; B = Al, Ga, In) ions: a battle between covalency and aromaticity, and prediction of square planar Si in SiIn42−/−

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Selected AB₄^2−/− (A = C, Si, Ge; B = Al, Ga, In) ions: a battle between covalency and aromaticity, and prediction of square planar Si in SiIn₄^2−/−