What is Chemical Crystallography?
Essentially, chemical crystallography describes the use of crystallography to study problems that are primarily of a chemical nature. Chemical Crystallography provides accurate and precise measurements of molecular dimensions in a way that no other science can begin to approach.
The Past
Historically, chemical crystallographers have tended to concentrate on using single-crystal X-ray diffraction to determine the structure of what may be thought of as “small molecules”; the upper limit might typically be considered to be up to a few hundred non-hydrogen atoms. Chemical crystallographers study compounds which are both of chemical and biological interest, e.g. new synthetic chemicals, catalysts, pharmaceuticals, natural products … the list is endless!
The Present
With more powerful radiation sources, better detectors and improvements in computing power, structure determination by powder diffraction has become increasingly important to chemical crystallographers, providing structures for flexible small molecules with up to hundreds of non-hydrogen atoms, as have charge density studies able to determine the localised electron density around molecules. Most recently our community has seen the emergence of electron diffraction, which has opened entirely new opportunities to study crystals traditionally too small for single crystal diffraction.
Chemical crystallography using single-crystal diffraction techniques has expanded beyond solely determining the structure of a molecule – increasingly, the interaction of molecules with each other in the solid state has become the focus of chemical crystallographic research. The systematic study of the way molecules pack in the solid (crystal engineering) has direct application in the pharmaceutical industry, in the study of polymorphism and further application in materials science for the design of new materials. It has also become feasible and important to study crystals in non-ambient environments to understand how (and why) materials behave the way they do in real-world and in operando conditions. This has come to include studying crystal structure under extremes of pressure and temperature, during excitation by laser light, and even within complicated reactors and devices, like running batteries!
Role of the CCG
The Group exists to promote and support the activities of the chemical crystallography community within the UK and Eire. To this end, several regular activities are organized:
- A one-day meeting in the Autumn on a topic of current interest in the field.
- Several sessions at the British Crystallographic Association’s Annual Spring meeting, often arranged in conjunction with the other Groups of the BCA.
- A prize is awarded to a “Young Scientist” based on a selection of his or her recent publications. This award is sponsored by the Cambridge Crystallographic Data Centre and is presented at the BCA Spring Meeting.
- A biennial intensive course in structure analysis, which lasts for 10 days and is held at the University of Durham. A review of the thoughts that led to the establishment of the Course was published in 2002 in the journal Zeitschrift für Kristallographie [view PDF]. Although the course is run independently of the CCG, the organisers and teaching staff are usually members of the CCG.
