Small molecules workshop

Image courtesy of Alan Jackson.

A workshop for potential users of the Australian Synchrotron was held at the U. of Melbourne School of Law, January 29-31, 2003. The workshop was part of the process of developing the first group of Australian Synchrotron beamlines to meet the needs of Australian science and industry. It brought together researchers who are using synchrotrons now and also those who could use the Australian Synchrotron in the future. International experts in synchrotron design, operation and experimentation helped enhance Australian understanding of what we can expect from the Australian Synchrotron and its beamlines.

Small molecule single crystal diffraction (SMX) made its first appearance at the workshop proceedings on the morning of the first day when R. Garret mentioned the ASRP’s SCrAPS program in an overview of Australian Synchrotron research. S. Hall gave a photon fast introduction to the usefulness of synchrotron light for small molecule single crystal studies, being restricted to a maximum presentation time of 5 minutes. The new version of the Australian Synchrotron, Boomerang20, is to be bigger, brighter and better and the beamline presenters clearly had to be correspondingly faster.

In the afternoon of the second day of the workshop, participants dispersed into beamline specific discussion groups (breakout groups) to discuss and prepare detailed summaries of the needs and costs for their proposed beamlines. The small molecule demand for beam time is unlikely to require a dedicated end station in the foreseeable future. Consequently the small molecule group, represented and led by S. Hall, have primarily pursued a share in one of the two beamlines being proposed for protein crystallography (PX). Small molecule crystallography and protein crystallography have significant areas of technical and scientific overlap; more so than with any other beamline group. Accordingly, the small molecule group primarily participated in the protein breakout session. The discussion session canvassed a number of technical, managerial and financial matters, and concluded that there were good reasons and no significant obstacles in having SMX share the proposed PX micro-crystallography undulator beamline.

The SMX group was fortunate to have S. Teat (Senior Station Scientist, Daresbury Lab Synchrotron, UK) present at the workshop. Simon is the manager of station 9.8, which is currently the only dedicated small molecule single crystal crystallography station at any synchrotron. Over the past year Simon and D. Cookson, Deputy Project Manager and beamline scientist at ChemMatCARS, have provided significant and valuable information for the case for a SMX facility at the Australian Synchrotron. As a visiting researcher he has an ongoing involvement in the commissioning of the small molecule beamline at ALS. At the protein crystallography discussion group he gave an impromptu overview of the benefits of synchrotron light for small molecule crystallography, and answered questions arising from that overview. He contributed to the technical, beamline cost assessment and synchrotron management discussions of the protein group. Simon also participated in the powder diffraction discussion group, where he gave a presentation on current trends in small molecule single crystal synchrotron crystallography.

The relevance of single crystal studies to powder diffraction was highlighted with an example of an incommensurate structure requiring single crystal synchrotron data for its structural resolution. In addition to providing structures and charge density distributions from weakly diffracting crystals, wavelength tuneable synchrotron light offers the possibility of utilising anomalous dispersion effects in single crystal diffraction, to reliably determine mixed metal site and multiple oxidation state occupancies. Simon's presentation to the powder group was followed by a brief assessment of the likely demand for SMX studies at Boomerang, from the perspective of my involvement in the SCrAPS program, and then S. Batten (Monash) further outlined areas of overlap between powder and single crystal interests from the small molecule perspective. The organisers should be congratulated for bringing potential users and experts together to more clearly define Boomerangs future shape.