Archive for April, 2012

Nanoswords, nanobelts and nanocombs, an expanding wardrobe for the nanopeople!

Lately it seems that nanoputian research hasn’t been particularly hot in the world of organic chemistry, however in crystal engineering the controlled morphological design of nanocrystals has arguably never been hotter. In the fields of biomedicine, optics and electronics the potential application of a variety of nanomaterials has sparked interest around the world, with nanotechnology potentially revolutionising science, technology, engineering and medicine.

A sample of FESEM images of the interesting nanocrystal morphologies created by the research team – check out the paper for more details!

The fundamental properties of any nanomaterial are ultimately determined by particle size and shape, so for every potential application it is crucial that morphology is carefully controlled so the materials possess the desired properties. This Hot Article from Wei Zhong et al. details the team’s investigations into a one-step evaporation process to produce a huge range of nanocrystal morphologies, including nanowires, nanoswords, nanobelts, nanocombs and branched nanorods. To find out how the team achieved this, download their article now, which is free to access for 4 weeks!

Design, growth, and characterization of morphology-tunable CdxZn1−xS nanostructures generated by a one-step thermal evaporation process
Zai-Xing Yang, Peng Zhang, Wei Zhong, Yu Deng, Chak-Tong Au and You-Wei Du

Interested in nanocrystals? You can also download these great articles which are also free to access!

Highly active ZnxCd1−xS photocatalysts containing earth abundant elements only for H2 production from water under visible light
Yabo Wang ,  Jianchun Wu ,  Jianwei Zheng and Rong Xu
Catal. Sci. Technol., 2011,1, 940-947
DOI: 10.1039/C1CY00143D

Nanostructured Titania: the current and future promise of Titania nanotubes
Kevin C. Schwartzenberg and Kimberly A. Gray
Catal. Sci. Technol., 2012, Advance Article
DOI: 10.1039/C2CY00538G

Digg This
Reddit This
Stumble Now!
Share on Facebook
Bookmark this on Delicious
Share on LinkedIn
Bookmark this on Technorati
Post on Twitter
Google Buzz (aka. Google Reader)

Crystallisation A Biological Perspective: Faraday Discussion 159

Crystallisation – A  Biological Perspective: Faraday Discussion 159The last ten years have seen a revolution in our understanding of the mechanisms of biological crystal growth.  Recent studies on crystal nucleation have found evidence of pre-nucleation clusters, a controversial result which apparently contradicts classical nucleation theory.

If you are working in the areas of biomineralisation, biomimetic crystallisation, nucleation or crystal growth then you are very likely to have some significant original research to share. Join a meeting where you can not only discuss your findings but also get them published.

l

Crystallisation – A  Biological Perspective: Faraday Discussion 159 is the place to be this July.

l

Crystallisation – A  Biological Perspective: Faraday Discussion 159Why choose to come to a Faraday Discussion? They have a unique format – all papers are circulated in advance and all discussion contributions are recorded for publication in the abstract book after the event. You can also have your own poster space at the meeting, so submit yours now before the deadline of 25 May.

Digg This
Reddit This
Stumble Now!
Share on Facebook
Bookmark this on Delicious
Share on LinkedIn
Bookmark this on Technorati
Post on Twitter
Google Buzz (aka. Google Reader)

Top ten most accessed articles in March

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

Syntheses, crystal structures and luminescent properties of Zn(ii)/Cd(ii) supramolecular complexes incorporating 4-sulfinobenzoate and its in situ oxidized ligand 
Huang Wang ,  Li-Hua Huo ,  Zhao-Peng Deng ,  Hui Zhao and Shan Gao  
CrystEngComm, 2012, 14, 3501-3508 DOI: 10.1039/C2CE06584C     

New compounds constructed from polyoxometalates and transition metal coordination complexes with lower positive charge 
Yan Wang ,  Yu Peng ,  Li-Na Xiao ,  Yang-Yang Hu ,  La-Mei Wang ,  Zhong-Min Gao ,  Tie-Gang Wang ,  Feng-Qing Wu ,  Xiao-Bing Cui and Ji-Qing Xu  
CrystEngComm, 2012, 14, 1049-1056 DOI: 10.1039/C1CE05633F     

Coordination polymers, metal–organic frameworks and the need for terminology guidelines 
Stuart R. Batten ,  Neil R. Champness ,  Xiao-Ming Chen ,  Javier Garcia-Martinez ,  Susumu Kitagawa ,  Lars Öhrström ,  Michael O’Keeffe ,  Myunghyun Paik Suh and Jan Reedijk  
CrystEngComm, 2012, 14, 3001-3004 DOI: 10.1039/C2CE06488J     

Facile synthesis of flower-like 3D ZnO superstructures via solution route 
Yongjiang Sun ,  Li Wang ,  Xuegang Yu and Kezheng Chen  
CrystEngComm, 2012, 14, 3199-3204 DOI: 10.1039/C2CE06335B     

One-pot shorter time synthesis of Cu2O particles and nanoframes with novel shapes 
Lihua Yang ,  Yongming Sui ,  Wenyan Zhao ,  Wuyou Fu ,  Haibin Yang ,  Lina Zhang ,  Xiaoming Zhou ,  Shuli Cheng ,  Jinwen Ma ,  Hui Zhao and Minghui Li  
CrystEngComm, 2011, 13, 6265-6270 DOI: 10.1039/C1CE05505D    
 
Porous TiO2 hollow nanospheres: synthesis, characterization and enhanced photocatalytic properties 
Haijiao Zhang ,  Guidong Du ,  Wenqi Lu ,  Lingli Cheng ,  Xuedong Zhu and Zheng Jiao  
CrystEngComm, 2012, 14, 3793-3801 DOI: 10.1039/C2CE06731E     

Construction of coordination frameworks based on 4-imidazolyl tecton 1,4-di(1H-imidazol-4-yl)benzene and varied carboxylic acids 
Shui-Sheng Chen ,  Yue Zhao ,  Jian Fan ,  Taka-aki Okamura ,  Zheng-Shuai Bai ,  Zhi-Hao Chen and Wei-Yin Sun  
CrystEngComm, 2012, 14, 3564-3576 DOI: 10.1039/C2CE06632G     

Porous organic molecular materials 
Jian Tian ,  Praveen K. Thallapally and B Peter McGrail  
CrystEngComm, 2012, 14, 1909-1919 DOI: 10.1039/C2CE06457J     

Cu-mediated solid-state reaction in a post-functionalized metal–organic framework 
Marie Savonnet ,  Jérôme Canivet ,  Serge Gambarelli ,  Lionel Dubois ,  Delphine Bazer-Bachi ,  Vincent Lecocq ,  Nicolas Bats and David Farrusseng  
CrystEngComm, 2012, Advance Article DOI: 10.1039/C2CE00017B     

pH-Dependent syntheses of copper–quinoxaline–polyoxotungatate hybrids: variable role of Keggin-type polyanion in different pH conditions 
Ying-Nan Chi ,  Feng-Yun Cui ,  Ai-Rui Jia ,  Xiao-Yu Ma and Chang-Wen Hu 
CrystEngComm, 2012, 14, 3183-3188 DOI: 10.1039/C2CE06327A     

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

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

Digg This
Reddit This
Stumble Now!
Share on Facebook
Bookmark this on Delicious
Share on LinkedIn
Bookmark this on Technorati
Post on Twitter
Google Buzz (aka. Google Reader)

CPOSS meeting

A few weeks ago, I attended the 6th annual meeting of the “Control and Prediction of the Organic Solid State” (CPOSS) project in the Old Refectory of University College London. The meeting was themed ‘Crystals or not – where do we go from here?’. There were over 100 delegates in attendance, with both academic and industrial members present.

Sally Price (University College London) opened the morning session with an outline of the CPOSS project achievements to date. Tackling the over-prediction of polymorphs, she issued a caution when deciding that unobserved thermodynamically feasible structures cannot appear. The case of the carbamazepine form V polymorph clearly demonstrated this, as it could in fact be isolated by seeded sublimation! Alastair Florence (University of Strathclyde) followed, focusing on the complementary nature of experimental and computational methods to characterise racemic and enantiopure naproxen. The calculated crystal energy landscape, binary melting point phase diagram, solubility measurements and limited solid-state screening, were all consistent with the racemic Pbca and enantiopure P21 compounds being the only practically relevant solid phases of the free acid naproxen.

A slight diversion in theme by Simon Gaisford (University College London) revealed a novel method for identifying polymorphs by thermal methods rather than crystallographic techniques. Different polymorphs have different melting temperatures and heats of fusion. By varying the rate of heating, it was possible to isolate a metastable carbamazepine-nicatinamide cocrystal polymorph. The final talk of the session was by Matthew Hapgood (University College London) who discussed the intriguing case of tetrolic acid, where the lowest global minima of the crystal energy landscape are not the actual alpha or beta polymorphs. By combining solution simulations and nanocrystalline molecular cluster stability calculations, it was possible to extract the actual crystal structures from predictions of energy landscapes.

Speakers at CPOSS

From left to right: Professor Chick Wilson (University of Bath), Dr Philippe Fernandes (formerly University of Strathclyde), Dr Sharon Cooper (University of Durham), Professor Sally Price (UCL), Professor Jon Steed (University of Durham), Professor Derek Tocher (UCL), Dr Matthew Habgood (UCL), Dr Doris Braun (UCL), Professor Alastair Florence (University of Strathclyde). Photo courtesy of Louise Price.

Following lunch and a busy poster session, the afternoon session started with a presentation by Jon Steed (University of Durham) on crystallisation in anion-switchable supramolecular gels, with a particular focus on producing materials with switchable flow characteristics. Sharon Cooper (University of Durham) offered an interesting way to try to overcome kinetic control of metastable polymorphs (such as the infamous case of Ritonavir) through the use of microemulsions driven by thermodynamic control for polymorphic compounds like mefenamic acid and γ-glycine. Phillippe Fernandes provided a personal overview of his experience in solid-state chemistry, both from an academic and an industrial point of view.

Doris Braun (University College London) emphasized that contact with water cannot be avoided during the manufacturing process of pharmaceuticals. The already complex crystal structure predictions thus require the additional step of hydrate formation predication in order to more accurately predict polymorph formation, such as for 2,4-Dihydroxybenzoic acid and 2,5-Dihydroxybenzoic acid. The session was concluded by Chick Wilson (University of Bath) as a champion of the Directed Assembly of Extended Structures Network. He presented the activities and future plans of this network, which aims to foster collaborations in order to be able to design, engineer and control materials for applications in frontier manufacturing and other industries.

The meeting was enjoyed by all, and was an excellent overview of the current status of structure prediction, as well as highlighting challenges still facing solid-state chemists. Look out for my interview with Sally Price also on the blog!

Digg This
Reddit This
Stumble Now!
Share on Facebook
Bookmark this on Delicious
Share on LinkedIn
Bookmark this on Technorati
Post on Twitter
Google Buzz (aka. Google Reader)

Interview with Sally Price

Sally PriceProfessor Sally Price works at University College London in the UK. Her group focuses on developing the accurate modelling of intermolecular and intramolecular forces, in order to predict which crystal structures of an organic molecule are thermodynamically feasible. These are contrasted with experimental searches for polymorphs in order to understand the factors which lead to polymorphism, in a multi-disciplinary project “Control and Prediction of the Organic Solid State” (CPOSS – 2012 meeting report to follow soon here on CrystEngComm blog!).

She is on the Crystal Growth and Design Advisory Editorial Board and was a member of the CrystEngComm Editorial Board when the journal was first launched. Here, she talks to CrystEngComm about her near miss as a tax inspector, and her fasincation with the theoretical and atomic level understanding of chemistry.

Why did you want to become a scientist?

I’ve always liked understanding how things fit together – I had a chemistry and a Meccano set as a child. The summer before I started my A-level course, I worked at ICI as a lab technician, and I can recall the reaction of my supervisor when I said I wanted to be a theoretical rather than experimental chemist. At that stage I had barely heard of quantum mechanics, and was only expressing a liking for theory as being able to quantify relationships between measureable properties and make predictions.

What projects are you working on at the moment?

How do we model the forces in flexible organic molecules? The organic solid state is a great challenge to our theories of modelling inter and intramolecular forces adequately.

What do you think will be the next big breakthrough in your field?

It would be a breakthrough if computational chemistry and molecular modelling actually lived up to the hype and expectations, but it should slowly become a reliable complement to experimental work. We still have a long way to go in developing crystallisation science to have a more reliable theory, let alone implement such a theory to predict which crystal structures will form under which conditions. The required breakthrough is probably in understanding nucleation and growth in more realistic systems.

How do you think crystal engineering will develop in the next couple of years?

I subscribe to the dream of being able to design the assembly of new materials with targeted properties, but with the caveat that this will probably be the optimal compromise between the huge range of different properties required. For example, for pharmaceuticals, the primary property is biological effectiveness, and crystal engineering should define the variability in solubility, dissolution rate, mechanical stability, and ability to be formulated into a good delivery system.

What is the most rewarding aspect of your work?

The sheer aesthetic pleasure when various experiments and calculations come together to give an atomic level understanding.

What is the secret to a successful research group?

The people and their commitment to really understanding their research problem. A group with a mutually supportive atmosphere, where everyone helps each other, and feels able to make and receive suggestions and constructive criticisms about each other’s work, will be able to build more effectively on the work in the field.

What achievement are you most proud of?

In science, my more confident predictions of new crystal structures being experimentally verified, such as carbamazepine form V.

What advice would you give to a young scientist?

Write and rewrite your work continually as you are going along. Draft your aims and introduction before you start, add method and results as you are going, stacking up material for the SI, and keep rewriting your arguments and conclusions. Writing it down ensures that you think more clearly and critically about what you are doing, than just talking about it.

What would you do if you weren’t a scientist?

When it looked as if the Research Council (SERC) would not be funding anyone in the round when my postdoc grant was ending, I started investigating becoming a tax inspector. However, the exchange rates fluctuated in the right direction, before I had to find out whether that second choice would have suited. I don’t think it would have provided such a varied and satisfying career.

What is your favourite space group and why?

P1 – easy to visualise

What was your first crystal structure?

I have never solved a crystal structure, let alone prepared a sample. I lack the manual dexterity for experimental work. However, the first crystal structure I studied in detail was chlorine, to show that the anisotropy in the atom-atom repulsion and electrostatics, arising from the lone pair density could account for this structure. It was my first application of the theory of intermolecular forces to modelling crystal structure.

Read more about Sally’s work in the RSC articles below…

Screening for cocrystals of succinic acid and 4-aminobenzoic acid
Nizar Issa , Sarah A. Barnett , Sharmarke Mohamed , Doris E. Braun , Royston C. B. Copley , Derek A. Tocher and Sarah L. Price
CrystEngComm, 2012, 14, 2454-2464
Part of the recent themed issue Crystal engineering and crystallography in the pharmaceutical industry

Hydrate formation of dihydroxybenzoic acidsWhich, if any, hydrates will crystallise? Predicting hydrate formation of two dihydroxybenzoic acids
Doris E. Braun, Panagiotis G. Karamertzanis and Sarah L. Price
Chem. Commun., 2011, 47, 5443-5445

A strategy for producing predicted polymorphs: catemeric carbamazepine form V
Jean-Baptiste Arlin , Louise S. Price , Sarah L. Price and Alastair J. Florence
Chem. Commun., 2011, 47, 7074-7076

Quantifying intermolecular interactions and their use in computational crystal structure prediction
Sarah (Sally) L. Price
CrystEngComm, 2004, 6, 344-353

Digg This
Reddit This
Stumble Now!
Share on Facebook
Bookmark this on Delicious
Share on LinkedIn
Bookmark this on Technorati
Post on Twitter
Google Buzz (aka. Google Reader)

April Crystal Clear: The Missing Crystal Fish

MOF Eu Eu-MOF fish & chips Crystal Clear CrystEngComm

Eu-MOF crystals which look suprisingly like chips or French fries

Fish and chips is a classic dish, however this month’s Crystal Clear is noticeably lacking in the crystal fish department. 

These chips (or French fries) are in fact crystals of a metal organic framework (MOF) constructed with Eu3+ and 1,3,5-Benzenetricarboxylic acid. The synthesis is performed in a mixture of water and DMF and the crystal size and shape can be manipulated by altering the ratio of the two liquids. 

The team from Qingdao and Changchun in China were looking at the influence additives and reaction conditions have on the MOF crystal morphology, these materials have interesting luminescence properties and potential application in colour displays and sensors. To read the full details of the teams discoveries take a look at Issue 8 of CrystEngComm, where you can also see how they were able to make ‘urchin-like balls’ as well as the pictured chips! l

ll

l

Solvothermal synthesis of luminescent Eu(BTC)(H2O)DMF hierarchical architectures
Biao Xu, Hailing Guo, Song Wang, Yuyang Li, Hongjie Zhang and Chenguang Liu

To keep up to date with the latest news sign up to our e-alerts, like us on facebook and follow us on twitter, and please do let us know if you know how to make crystal fish…

Digg This
Reddit This
Stumble Now!
Share on Facebook
Bookmark this on Delicious
Share on LinkedIn
Bookmark this on Technorati
Post on Twitter
Google Buzz (aka. Google Reader)