CrystEngComm Blog

Kari Rissanen

Professor Kari Rissanen is an Academy Professor at the Academy of Finland, where he is currently on leave from the University of Jyväskylä. He was first elected as Associate Professor of Organic Chemistry at University of Joensuu after completing his PhD in chemistry at the University of Jyväskylä. His main interests lie in the fields of supramolecular chemistry, nanochemistry and X-ray crystallography, with a particular focus on weak intermolecular interactions in solid state materials, solutions and gaseous phases. His group are currently working on new self-organising organic nanoreactors, utilising combinations of metal coordination or halogen bonding, and halogen-bonded and organic two- or three-dimensional frameworks. Here he talks with CrystEngComm about his first crystal structure, and his many projects in the field of supramolecular chemistry.

Why did you want to become a scientist?

I have been always interested in natural sciences, especially chemistry, and at best scientific research can be like detective work.

What projects are you working on at the moment?

My research is primarily based around the following Academy of Finland funded projects:

• Self-assembly of nano-sized supramolecular assemblies
• Functional materials by metal-directed self-assembly
• Supramolecular complexes and networks – design, photocontrol and function
• Intramolecular charge transfer (ICT) based fluorescent probes for monitoring zinc(II) and anions in gold nanoparticles
• New water-soluble chemo-responsive luminescent materials
• Weak interactions as structural elements in self-assembling molecular systems

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

The full utilization of the sub-component self-assembly principle (pioneered by Jonathan Nitschke, Cambridge, UK).

How do you think Crystal Engineering will develop in the next couple of years?

To the understanding and utilization of the hierarchical order of multiple and simultaneously active weak intermolecular interactions.

What is the most rewarding aspect of your work?

I really enjoy being able to help and tutor my students, postdocs and colleagues in resolving their difficult structural problems.

What is the secret to a successful research group?

Motivation and dedication to the research and persistence in overcoming encountered difficulties are all key to the success of a research group.

What achievement are you most proud of?

Winning two consecutive 5-year Academy Professorships – this is the most prestigious scientific research position in Finland.

What advice would you give to a young scientist?

Learn the basics well and keep an open and keen mind to everything new. Focus on your research and try to look it from a different perspective. In case of difficulty seek advice and help from more experienced colleagues and mentors.

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

Actually I have never though about this possibility, but maybe some kind of high school teacher?

What is your favourite space group and why?

R-3. Only 4 of my 850 published structures have this space group and in each case this space group has revealed a very interesting structure.

What was your first crystal structure?

Nickel salicylate. This was a product of my M.Sc thesis work which was published in Acta Chemica Scandinavica in 1987.

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

Self-ordering of metallogrid complexes via directed hydrogen-bonding
Artur R. Stefankiewicz, Guillaume Rogez, Jack Harrowfield, Alexandre N. Sobolev, Augustin Madalan, Juhani Huuskonen, Kari Rissanen and Jean-Marie Lehn
Dalton Transactions, 2012, Advance Article

Cooperativity of H-bonding and anion–π interaction in the binding of anions with neutral π-acceptors
Michael Giese, Markus Albrecht, Tim Krappitz, Marius Peters, Verena Gossen, Gerhard Raabe,  Arto Valkonen and Kari Rissanen
Chem. Commun., 2012, 48, 9983-9985

Interaction between amines and N-haloimides: a new motif for unprecedentedly short Br···N and I···N halogen bonds

Professor 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

Which, 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

Professor Alessia Bacchi completed her undergraduate and graduate studies at the University of Parma. After completing a two year post doc in the European Molecular Biology Lab in Hamburg, she returned to the University of Parma in October 1998. Since October 2001, Alessia has been Associate Professor in the Faculty of Science, investigating the supramolecular organization in crystals as a model for the description of multicomponent systems and for the realization of new materials with complex properties. She is on the European Crystallographic Association Executive Committee and is the past chair of the IUCr Commission on Structural Chemistry. Here, she talks to CrystEngComm to tell us about her hopes for understanding crystal nucleation; her fascination with molecular models; and her enthusiasm for educating young researchers and students.

Why did you want to become a scientist?

I wanted to capture the deepest reasons behind what I could see. I have always been fascinated by building models to explain things.

What projects are you working on at the moment?

We are designing molecular materials that can adapt their solid state organization to include and reversibly release small guests, by reacting to external stimuli. We also work on polymorphs – a fascinating world where the more you look at things, the more you see fine details and unexpected results.

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

I believe that understanding the process of nucleation, the very first stages of the birth of a crystal, would be a real step forward for scientists who design and fabricate crystalline materials.

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

The field is already on the cusp of fabricating novel materials with applications in the field of nanosciences in general. Also, control of crystal forms is becoming affordable. In a nutshell: less space for serendipity, more emphasis on control.

What is the most rewarding aspect of your work?

I still get excited when a prediction comes true, or when at the end of a lot of hard work I finally see the reason behind a particular observation. The education of young researchers and students is also an extremely rewarding aspect of academic life.

What is the secret to a successful research group?

To know each other’s strengths and weaknesses, and to be able to compensate one’s faults with someone else’s skills.

What achievements are you most proud of?

From a professional point of view, I was very proud to be invited as a lecturer at the Erice School in 2007. Erice schools are a real richness for the soul. On the research side, I cite two cases where I felt very proud that my predictions came true…

Just after finishing my PhD I predicted that there should be conformational polymorphism for rifamycins (a well known family of antibiotics) because I had been able to formulate a model of molecular flexibility previously overlooked (published in Journal of Medicinal Chemistry and Journal of Computer-Aided Molecular Design). Then I planned an unconventional crystallization experiment and ‘eureka’ the predicted form was there! I still remember the joy when I first saw the structure (published in New Journal of Chemistry). More recently, I had the crazy idea to predict the strength of intermolecular interactions by measuring crystal shape, and it worked! (published in Angewandte Chemie International Edition).

What advice would you give to young scientists?

To be ambitious and passionate in their work, to be honest and kind with colleagues and young students. Being a good person is the most important thing.

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

I would have probably become a teacher, or a medical doctor (or an explorer, or an archeologist, or a detective, or a champion at the Olympic Games….!)

What is your favourite space group and why?

P2₁2₁2₁, because the origin is not in an obvious place or at the intersection of anything.

What was your first crystal structure?

A ligand that I synthesized during my thesis: bis(2-Pyridyl)ketone (phenyl(semicarbazono)acetyl)hydrazone monohydrate (CSD refcode PEBMAK)

Read more about Alessia’s research in the CrystEngComm articles below…

Water vapour uptake and extrusion by a crystalline metallorganic solid based on half-sandwich Ru(II) building-blocks
Alessia Bacchi, Giulia Cantoni, Michele R. Chierotti, Alberto Girlando, Roberto Gobetto, Giuseppe Lapadula, Paolo Pelagatti, Angelo Sironi and Matteo Zecchini
CrystEngComm, 2011, 13, 4365–4375

Effects of “changing the wheels” on the inclusion properties in metal–organic diols
Alessia Bacchi, Mauro Carcelli, Tiziana Chiodo and Francesco Mezzadri
CrystEngComm, 2008, 10, 1916–1927

Unusual hydrogen bonded (OH)₄ tetrahedral nests organize zinc(II) coordination complexes in a non covalent diamondoid network
Alessia Bacchi, Elsa Bosetti and Mauro Carcelli
CrystEngComm, 2007, 9, 313–318