The 2012 meeting for the Control and Prediction of the Organic Solid State Project will take place on Tuesday 3rd April 2012 at University College London from 9am – 4pm.
The meeting theme is “Crystal or not –where do we go from here?”, and features a variety of speakers including Alastair Florence, ChemComm Editorial Board member Jon Steed, and Sally Price (who will soon be featured in a CrystEngComm interview – watch this space!).
Register now. The meeting is free to attend.
Interest in Metal-Organic Frameworks (MOFs) has escalated in recent years due to potential applications in gas storage, catalysis and ion-exchange. The growing demand for these multifunctional materials imposes expectations of certain properties, which are often met by variations in construction and choice of linking ligands.
This Advance Article by Francisco Javier Martínez Casado and colleagues from Spain and Italy reports the synthesis, structural characterisation and photophysical properties of two new lead(II) butyrate-based compounds, with 3-dimensional MOF architechtures. Metal and ligand selection were targeted towards obtaining active luminescent materials, particularly due to the intense optical properties of lead(II) and the characteristic amphiphilic behaviour (organic or inorganic) of the family of metal alkanoates, also known as ‘metal soaps’.
The crystal structures of the compounds are very similar, with luminescence detected for the first time during data collection (see left). Analysis of the photoluminescence properties by UV-Vis absorption spectroscopy and steady-state fluorescence and lifetime measurements revealed exciting optical properties for the two lead(II) compounds. Excitation by UV radiation resulted in intense fluorescence indicating potential applications in the tuning of emission energies of MOFs. Future work in this area will explore these crystalline systems as potential host structures to generate electro- and photo- responsive materials for novel molecular devices.
Read the full article to find out more!
Luminescent lead(II) complexes: new three-dimensional mixed ligand MOFs
Francisco Javier Martínez Casado, Laura Cañadillas-Delgado, Fabio Cucinotta, Andrés Guerrero-Martínez, Miguel Ramos Riesco, Leonardo Marchese and José Antonio Rodríguez Cheda
CrystEngComm, 2012, Advance Article
DOI: 10.1039/C2CE06546K
Edwin Constable and colleagues at the University of Basel, Switzerland have reported the intercalation of a fullerene molecule into a network containing octahedral nickel nodes. Using a layering technique, crystals of 1,2-dichlorobenzene and fullerene templated nickel coordination networks were grown and characterised by IR spectroscopy and single crystal X-ray diffraction. The encapsulation of fullerene results in the assembly of [3 + 3] macrocycles, connected into 2-dimensional sheets through the nickel nodes and fullerene-free [6 + 6] macrocycles.
Read the full paper to find out more, and to see the pretty structures!
Bucky-blocks: templating a coordination network with C60
Edwin C. Constable, Guoqi Zhang, Catherine E. Housecroft and Jennifer A. Zampese
CrystEngComm, 2012, Advance Article
DOI: 10.1039/C2CE06156B
The annual meeting of the American Crystallographic Association will be held 28th July – 1st August 2012, in Boston, Massachusetts, at the Westin Waterfront Hotel.
The deadline for abstracts to be considered for oral presentations and posters is 31st March 2012, to be submitted online. 40% of all talks will be from contributed abstracts.
Scientific sessions are organized by the 12 Scientific Interest Groups (SIGs) within the Association, covering a diverse range of crystallography. There are four award presentations and lectures scheduled, including John Spence (Buerger award), Paul Fenter (Warren award), Ron Hamlin (Supper Instrumentation Award), and Emmanuel Skordalakes (Etter Early Career Award). The meeting will be preceeded by a series of workshops covering data refinement and crystallographic education.
Registration is now open! Book now to take advantage of the Early Bird Rate, which will close on 31st May 2012. The deadline for travel grants for students and young scientists is 31st March 2012.
Solid form informatics is the use of knowledge-based techniques to evaluate and analyse structures, as well as to predict properties. Identifying solid forms of drugs with suitable physiochemical properties and reducing the late-stage appearance of additional drug forms are very attractive financial prospects for the pharmaceutical industry.
In this CrystEngComm advance article, Peter Galek and colleagues at the Cambridge Crystallographic Data Centre use a series of tools available in the Cambridge Structural Database System to analyse the 500,000th structure, deposited by Sridhar and Ravikumar (CSD Reference Code: EFEMUX01). Lamotrigine is an approved drug (marketed in the US as Lamictal) for the treatment of bipolar disorder, with considerable anticonvulsant activity.
By using a comprehensive series of molecular, intermolecular and supramolecular analyses, methylparaben is identified as the optimal candidate from five pharmaceutically acceptable co-formers for lamotrigine. This correlates well with experimental data previously published by Miranda Cheney and colleagues, confirming the team’s prioritisation of potential conformer candidates for lamotrigine through detailed assessment of shape complementarity and hydrogen bond propensity.
Read the full article to find out more…
One in half a million: a solid form informatics study of a pharmaceutical crystal structure
Peter T. A. Galek, Elna Pidcock, Peter A. Wood, Ian J. Bruno and Colin R. Groom
CrystEngComm, 2012, Advance Article
DOI: 10.1039/C2CE06362J
The annual spring meeting of the British Crystallographic Association will be held at Warwick University from 16th to 19th April 2012.
The theme this year is ‘Challenges in Crystallography’ to reflect the upcoming Olympics in London in 2012. The deadline for abstracts to be considered for oral presentations and posters is 16th January 2012, to be submitted online at http://crystallography.org.uk/
Sessions include Hydrogen Bonding, Phase Transitions and Multidimensional Approaches. Confirmed plenary speakers include Branton Campbell, Laurence Pearl and Robin Taylor. The first day of the meeting will be the Young Crystallographers satellite meeting, containing presentations and poster sessions from students and young researchers. The meeting is organised by the 2012 planning committee, and chaired by Kirsten Christensen of the University of Oxford.
Registration is now open! Book Now to take advantage of the Early Bird Rate, which will close on 12th March 2012.
The reknowned capabilities of TiO2-based materials in photocatalytic oxidation of organic pollutants and in photoelectrochemical conversion of solar energy are inherently limited by the poor quantum efficiency of titanium. Research in this area is targeting improved generation and separation of photoinduced electron-hole pairs in TiO2 in order to enhance photocatalytic activity.
In this CrystEngComm Advance Article, Mingyi Zhang and colleagues at the Northeast Normal University in Changchun, China, report the synthesis and characterisation of a series of Bi2MoO6 nanostructures grown on TiO2 nanofibers. These hierarchical heterostructures demonstrate improved photocatalytic activity due to the narrow band gap energy of Bi2MoO6 which be easily excited by visible light to induce the generation of photoelectrons and holes.
The novel synthetic route to these nanofibers combines both the electrospinning technique and the solvothermal method in order to tune the coverage density and morphology of the nanostructured Bi2MoO6. The hierarchical heterostructures exhibited a high visible light photocatalytic behaviour for the decomposition of Rhodamine B, indicating potential applications of these nanofibers in wastewater treatment.
Find out more about these Bi2MoO6/TiO2 nanofibers in this CrystEngComm Advance Article.
One-dimensional Bi2MoO6/TiO2 hierarchical heterostructures with enhanced photocatalytic activity
Mingyi Zhang, Changlu Shao, Jingbo Mu, Zhenyi Zhang, Zengcai Guo, Peng Zhang and Yichun Liu
CrystEngComm, 2012, DOI:10.1039/C1CE05974B
Dan Shechtman copyright Technion
Professor Dan Shechtman holds the Philips Tobias chair of Materials Science at Technion – Israel Institute of Technology. Prof. Shechtman was an NRC fellow at the aerospace Research Laboratories at Wright Patterson AFB, Ohio, where he studied for three years the microstructure and physical metallurgy of titanium aluminides. In 1975 he joined the department of materials engineering at Technion. In 1981-1983 he was on sabbatical at the Johns Hopkins University, where he studied rapidly solidified aluminum transition metal alloys (joint program with NBS). During this study he discovered the Icosahedral Phase which opened the new field of quasiperiodic crystals. In 1992-1994 he was on sabbatical at NIST, where he studied the effect of the defect structure of CVD diamond on its growth and properties. For the past 6 years he has also been a part time faculty member of Iowa State University. He recently won the Nobel Prize in Chemistry 2011 for his discovery of quasicrystals.
What achievement are you most proud of?
The whole thing. I have opened a door to something new in crystallography, and many crystallographers came in through it, resulting in a paradigm shift. Many believed, many did not, and so it was a battle of minds for ten years.
In 1982, I was alone, and couldn’t explain my results. In 1984, I returned to Technion, where my colleague Ilan Blech was the first to believe in my findings, and helped by elucidating the structure and building a model to explain this phenomenon. We submitted this in 1984 to the Journal of Applied Physics, but it was rejected, and we finally managed to publish it in Metallurgical and Materials Transactions more than half a year later. In the meantime, John Cahn (my colleague at NIST) and the French crystallographer Denis Gratias became involved with the project, and we submitted a short paper to Physical Review Letters based on my original results from day one. In the period that followed, many scientists accepted quasicrystals, but there were still many people who rejected the idea, including the International Union of Crystallography (IUCr). They wanted single crystal X-ray diffraction results to definitively confirm the existence of quasicrystals.
Between 1984 and 1987 many attempts were made to grow crystals big enough for single crystal X-ray diffraction, and two groups in Japan and France achieved it. I presented these results at the 14th IUCr Congress in Perth, Australia, and the crystallographic community finally said ‘OK Danny, now you are talking!’ and they established a committee to redefine crystals. This was very meaningful, as it demonstrated that the community could be open to new discoveries.
What drove you to stand by your results, even though you knew many people would challenge them?
Most of the people in my close environment who knew didn’t believe and were very negative about my findings, and some were even negative towards me. Some of my colleagues at NIST, where I was on sabbatical, were more subjective. My host John Cahn told me: ‘Danny, this material is telling us something, and I challenge you to find out what it is.’
I am my own worst critic. I tried everything necessary in order to convince myself that I knew what it was not. No one had a better explanation. I remember the discovery date well, April 8 1982.
Electron diffraction played a fundamental role in the discovery of quasicrystals, and it is still a growing field. What are your thoughts on electron diffraction?
Electron diffraction is a wonderful tool, and nowdays it can be a wonderful crystallographic tool. Before electron diffraction was not as precise, but now using convergent beam electron diffraction we can determine with precision the structure of tiny crystals. Electron diffraction is the tool for discovery.
What projects are you working on at the moment?
I am looking at a range of materials, such as the B2 materials which are intermetallics. There are B2 materials which are very brittle, but we are working on some which are very ductile. We are now working mostly with Mg alloys for various applications, such as biodegradable and biocompatible implants and as antibacterial materials to fight bacterial infections.
What will be the next big breakthrough?
Nobody knows! Great discoveries are stumbled on. If you are clever enough you will work hard on a problem and elucidate the answer.
Do you have any advice for young scientists?
Be an expert in something, regardless of what it is. I was good at electron microscopy, but you can be good at X-ray diffraction, synthetic chemistry etc. Read everything, familiarise yourself with the instrumentation and methodology so that when you see something different, you will realise and know that it is different, rather than thinking it is an anomaly or an error.
Find out more about Dan Shechtman on his webpage at Technion Institute of Technology. You might also be interested in reading more in my recent blog on Professor Shechtman’s Nobel Prize.
Why not check out Chemistry World’s recent story on this year’s award too!
Professor Gautam Desiraju was born in Madras, India, and received his B.Sc. at the University of Bombay, India, in 1972. He was awarded his Ph.D. from the University of Illinois at Urbana-Champaign, USA, in 1976. After two years at Eastman Kodak Company, Rochester, New York, USA, he joined the faculty at the University of Hyderabad, India. He left the University of Hyderabad in 2009 and is currently at the Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore. He was recently was elected President of the International Union of Crystallography (IUCr) during the IUCr General Assembly in Madrid, Spain for the triennium 2011-2014.
Prof. Desiraju was one of the founder members of the CrystEngComm Editorial Board and has also served on the Editorial Advisory Board of ChemComm. His 1989 book on crystal engineering and 1995 review in Angewandte Chemie on supramolecular synthons redefined several aspects of the subject of crystal engineering, and in particular led to an emphasis on the study of hydrogen bonds and other intermolecular interactions.
Why did you want to become a scientist?
I always liked chemistry, I was fascinated by it. During my first lab experiment in chemistry I remember thinking I didn’t want to do anything else. I was very lucky that I had the opportunity to do what I liked.
What projects are you working on at the moment?
So many projects that I have lost count! Currently I have at least 10-15 projects underway in my group. We are very excited about nanoindentation, which is a new technique that allows us to experimentally compare the interaction strengths and monitor anisotropy of molecular crystals. This requires a very good student as it is a very laborious process – you need to know the faces of the crystal really well.
What do you think will be the next big breakthrough in your field?
If I knew what it was, I would be doing it! The beauty of scientific research is that you never know. If you could predict the next breakthrough, everyone would have gotten there!
How do you think Crystal Engineering will develop in the next couple of years?
There is no doubt that crystal engineering has spread far and wide. Unlike other areas in crystallography, it has attracted lots of people and interest, even though it is hard. Big ideas in chemistry are sustained when there is commercial application because this brings in money to attract research. Crystal engineering is very lucky as areas like metal-organic frameworks and pharmaceuticals are very big and have lots of money, and so there is lots of interest. The commercial applications and the challenge are an irresistible temptation. No subject addressed by the both the RSC and ACS can be small.
According to the evolutionary model it is the survival of the fittest, and so the not so good areas of science will die out because of the lack of support. These are not good times for science, and we do need to worry about it. However, the future is very bright for crystal engineering, as the pharmaceutical industry sustains the organic research, and the chemical industry sustains the metal-organic framework research.
What is the most rewarding aspect of your work?
Just the fun of doing it! Scientists like me are very lucky as we work with young people all the time, which keeps both the scientist and the young person active. Other careers such as medicine, police, etc. are not so happy because they are not exposed to young people as much, but we are fortunate enough to see the ‘innocence of life’ all the time.
What is the secret to a successful research group?
This really depends on the personality of the research advisor, because they are the central person in the group. As the manager it is their role to get the best output possible out of the team depending on how they motivate the people around them. It is a very fine balance between happiness and productivity. There should be an abundance of both in every research group.
What achievement are you most proud of?
Pride is a bad word. All scientists like to do their own thing. Serious scientists would do this irrespective of anything. It is best when you do it for yourself and it interests your peers. For my plenary at the IUCr Congress in Madrid I specifically kept the material to be recent, and even though there was a large lecture hall full of people at 9am on the last day of the conference, I could have easily have given that talk to myself, as it gives me the greatest happiness to explore my work.
What advice would you give to a young scientist?
Go have fun in the lab. Be bold and do what you like to. Let go of inhibition and remember that your training is only a platform so you don’t do nonsense. Research is highly individual, and you have to do your own thing. Think like this from the very beginning.
What would you do if you weren’t a scientist?
I would have studied history or sociology.
What is your favourite space group and why?
P21/c with Z’=1 (not 0.5 + 0.5), because this is the norm, and merits no further consideration. Anything else needs a chemical explanation, as this condition requires no chemistry. What is not P21/c with Z’=1 is crystal engineering/me.
What was your first crystal structure?
It was horrible! I did my PhD in the US in 1975, and we had to hand-centre the reflections before data collection! It was hard work and lots of effort to turn arcs on this enormous machine. The structure was in Pbca with a c-axis of 44Å and very close spots. I was baptised by fire! You never forget the first!
Find out more about Gautam Desiraju on his webpage at the Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore
Read some of Gautam’s exciting research in the following articles:
Shape and size mimicry in the design of ternary molecular solids: towards a robust strategy for crystal engineering
S. Tothadi, A. Mukherjee and Gautam R. Desiraju
Chem. Commun., 2011, Advance Article
DOI: 10.1039/C1CC14567C
Drug-drug co-crystals: Temperature-dependent proton mobility in the molecular complex of isoniazid with 4-aminosalicylic acid
Pawel Grobelny, Arijit Mukherjee and Gautam R. Desiraju
CrystEngComm, 2011, 13, 4358-4364
From themed issue Dynamic behaviour and reactivity in crystalline solids
Nature and strength of C–H···O interactions involving formyl hydrogen atoms: computational and experimental studies of small aldehydes
Tejender S. Thakur, Michael T. Kirchner, Dieter Bläser, Roland Boese and Gautam R. Desiraju
Phys. Chem. Chem. Phys., 2011, 13, 14076-14091
From themed issue Weak hydrogen bonds – strong effects?
The Royal Swedish Academy of Sciences has awarded the Nobel Prize in Chemistry for 2011 to Dan Shechtman from Technion – Israel Institute of Technology, Haifa, Israel “for the discovery of quasicrystals”. His discovery of a ten-fold diffraction pattern from the rapidly cooled alloys of Al with 10—14 at. % Mn, Fe, or Cr in 1982 fundamentally altered how scientists conceive of solid matter. At first Shechtman didn’t believe the atoms in his crystal were packed in a pattern that could not be repeated, as aperiodicity was forbidden. However he realised that the image he saw in his electron microscope was correct and what he had learnt was wrong, standing by his very controversial discovery to the point of being asked to leave his research group.
In 1984, along with Ilan Blech, John Cahn, and Denias Gratia, Shechtman finally had the opportunity to publish his data, reporting a crystal with “long-range orientational order, but with icosahedral point group symmetry, which is inconsistent with lattice translations. Its diffraction spots are as sharp as those of crystals but cannot be indexed to any Bravais lattice”,1 which would eventually be known as a quasicrystal. Through the application of Alan Mackay’s model for aperiodic diffraction patterns of atoms to Shechtman’s data by the physicists Paul Steinhardt and Dov Levine, it was discovered that Mackay’s theoretical tenfold symmetry actually existed in Shechtman’s diffraction pattern.2 Today quasicrystals constitute an entire area of science by themselves, spanning chemistry, physics, materials science and mathematics.
These perfectly ordered materials that never repeat themselves are mostly produced artificially in laboratory environments. The 1st naturally occurring quasicrystals were recently discovered in the mineral icosahedrite (Al63Cu24Fe13) from the Khatyrka River in Russia,3 and a Swedish company has also found quasicrystals in a certain form of steel. Whilst the idea of quasicrystals was completely novel, 2D aperiodic patterns had been identified in many old Arabic murals from the 13th century onwards, and also in Penrose tiles in the 1970s, where regular patterns never repeat themselves. By transcribing this aperiodicity to three dimensions, Shechtman instigated a paradigm shift in materials chemistry that forced scientists to reconsider their perception of the very nature of matter.
Sven Lidin – Member of the Nobel Committee for Chemistry 2011
1. Metallic Phase with Long-Range Orientational Order and No Translational Symmetry
Dan Shechtman, Ilan Blech, Denias Gratias, and John W. Cahn
Phys. Rev. Lett., 1984, 53, 1951–1953
2. Quasicrystals: A New Class of Ordered Structures
Dov Levine and Paul J. Steinhardt
Phys. Rev. Lett., 1984, 53, 2477–2480
3. Icosahedrite, Al63Cu24Fe13, the first natural quasicrystal
Luca Bindi, Paul J. Steinhardt, Nan Yao, and Peter J. Lu
Am. Mineral., 2011, 96, 928–931
