A single-crystal X-ray diffractometer for the structural analysis of molecular compounds, macromolecules and materials

Understanding the structure of chemical compounds is of paramount importance in understanding their behaviour, physical properties and reactivity. Single crystal X-ray diffraction (SXRD) is a critical analytical technique for the analysis of materials including molecules, supra- and macro-molecular compounds (e.g. proteins), and extended solids. It is, unquestionably, the most powerful analytical technique available for the characterisation of compounds with ordered structures, and as such, is widely used by a broad scientific user base including chemists, materials scientists and physicists.

X-ray analysis has driven enormous advances in chemistry, materials science and beyond. The U.K. has pioneered the development and application of this technique as evidenced by the award of Nobel Prizes to W. H. Bragg and W. L. Bragg (Physics 1915) and to D. M. C. Hodgkin (Chemistry 1964) for their seminal contributions to the field. It is still routinely used in laboratories worldwide, however conventional commercial diffractometers have reached the limit of their utility for the analysis of certain samples. As our control of chemical reactivity has advanced, so too has the complexity of the compounds we produce. Nowadays chemists routinely produce molecules and solids that are increasingly elaborate, which in turn creates significant problems for conventional X-ray diffraction. The crystals obtained for such compounds tend to be smaller than for routine samples, and diffraction can be weaker due to disorder and/or defects in their structure. This requires increasingly powerful X-ray sources and highly sensitive detectors. In order to address this issue, scientists have made use of highly intense X-ray radiation from synchrotron sources (e.g. I19 at the Diamond Light Source), however access to such facilities is, understandably, time-limited and highly competitive.

Modern state-of-the-art diffractometers, such as the instrument for which we are bidding, rival the performance offered by synchrotrons allowing for the 'in-house' analysis of increasingly complex systems. They also enable exploratory time-intensive research (such as the measurement of single-crystal-to-single-crystal transformations, or variable temperature measurements to probe fluxionality) that would be prohibitively time-consuming at national facilities. The increased utility of such instruments is due to colossal advances in X-ray sources, and particularly, in X-ray detector technology. These advances have opened up fascinating new opportunities in the solid-state characterisation of molecules, which allow for the study of highly complex chemical systems (e.g. molecular machines or biologically relevant macromolecules). Moreover, access to such powerful instruments without time constraints permits for the exploratory study of compounds at broad temperature ranges in order to correlate structural changes with data available from other complementary analytical techniques such as magnetic resonance (NMR and EPR) or SQUID magnetometry. This will open up new opportunities in the characterisation of molecules and solids which will drive forward cutting-edge research and ensure that the U.K. remains at the forefront of scientific research in years to come. The impact of this research will be felt by researchers working across the physical and life sciences, and ultimately, by the global population as such science drives future advances in healthcare, the development of a circular economy and the design of new technologies which will have an impact on our everyday lives.