Rigaku Spider X-ray Diffractometer
About the Instrument:
This is an extremely versatile tool for determining the structure of crystalline materials, including small or weakly diffracting crystals. The combination of a very intense X-ray source, excellent optics and a curved image plate detector gives the instrument great versatility and sensitivity. “If it’s crystalline and we can see it under the microscope then we should be able to get the structure,” says Massey chemist Shane Telfer, “In conventional systems you’d struggle with crystals smaller than 10 microns but with our system we can go right down to about 2 microns.” It can also do powder diffraction, which gives basic structural information for samples that can’t be grown into single crystals. The X-Ray source for the Spider had been installed at Massey for a number of years and was being used by Shane’s colleague Geoff Jameson for his protein diffractometer. The source was originally funded by the Alan Wilson Centre for Molecular Ecology and Evolution. It was just a fortunate coincidence that it has an extra X-ray port. “So it was just waiting for the instrument,” says Shane. “We could easily move it up to that port, open the window and use those x-rays.” It is unusual to combine such a high intensity X-ray source with a single crystal system but the result has exceeded everyone’s expectations.
Often it is difficult to grow crystals large enough to get good X-ray diffraction data. The Spider’s small crystal capability means that researchers can spend less time growing crystals and more time forwarding their research. In just over 6 months of operation the Spider has had a huge impact. Shane’s group are developing porous metal/organic structures to use as catalysts. “The only realistic way you can determine the structure of these materials,” he explains “is by X-ray diffraction.” There are three conventional single crystal diffractometers in New Zealand but none with the capability of the Spider. “We were sending crystals away to Auckland or Canterbury and paying three or four hundred dollars a sample,” says Shane. “Having it in house we can do things immediately. There are no worries about deterioration of the samples and the students can learn how to do it as well. They become very familiar with the technique… so from an educational point of view it’s a massive advance.”
You can see in the Spider’s log book that it has been in almost constant use since it was installed in November “08. There are already four different groups from Massey using the instrument and several more are interested. The instrument has also drawn researchers from around New Zealand and the USA who are unable to decipher the crystal structure on their conventional systems. So far all of Shane’s collaborators have gone away satisfied. For longer term projects Shane is happy to train researchers. After that they can just book time on the instrument – no strings attached. The lab operates on a cost recovery basis so users are asked to pay a small amount for consumables. One of the more exciting collaborations to emerge with the Spider is one with super- conductor expert Jeff Tallon from Callaghan Innovation (CI). This is a story that draws together institutions, disciplines and countries. Jeff had heard about the Spider’s capabilities and was keen to use it to analyse his metal/organic composite materials that show potential as super-conductors. An opportunity arose when a physics student, who was funded to do a PhD at Massey, took a summer job with Jeff at CI. The student was keen to stay on with him at CI so Jeff used his MacDiarmid funding to provide a PhD chemistry student to work with Shane at Massey. It works well for everyone. Jeff gets help with synthesis and Spider measurements and Shane is enjoying working in a new and exciting area. “It’s a great team,” says Shane. “Before it happened, it would be difficult to imagine collaborating with someone like Jeff, but I think that’s the best kind of collaboration. There’s a nice complementarity there.”Shane believes that New Zealand universities provide an ideal environment for this kind of collaboration – “because the personal barriers here are low and people will generally talk to anyone else”. The equipment is just a good excuse to get together.
Our principal objectives are to devise interesting molecule-based materials and develop methods for their synthesis. These materials incorporate transition metals in both structural and functional roles. We have a particular fascination with chiral assemblies and materials. At a more detailed level, our two major focal points are: Metal-organic frameworks (MOFs). These are MOFs are porous, […]