With this award from the Major Research Instrumentation (MRI) Program, Professor Arnold Rheingold from University of California San Diego will upgrade an X-ray diffractometer with a high-flux, high-energy microfocus source and a new detector. The award will enhance research training and education at all levels, especially in areas such as (a) carbon dioxide-fixation chemistry, (b) designed protein synthesis, and (c) studies of post-synthetic metal-organic framework modification.
An X-ray diffractometer allows accurate and precise measurements of the full three dimensional structure of a molecule, including bond distances and angles, and provides accurate information about the spatial arrangement of a molecule relative to neighboring molecules. The high-flux, high-energy source will generate a high flux of X-ray that will allow studies of very small crystals or poorly diffracting crystalline materials. The studies described here will impact a number of areas, including organic and inorganic chemistry, materials chemistry and biochemistry. This instrument will be an integral part of teaching as well as research not only at UC San Diego but many other neighboring universities and colleges.
The installation of the Bruker Ultra diffractometer, which incorporates a rotating-anode source, has been a major factor in the overall growth of the X-ray diffraction laboratory at UCSD. It’s extraordinary power and sensitivity has meant that we have been able to accommodate and complete a far greater range of submissions than was previously possible using only sealed-tube sources. It is now the instrument of choice in the laboratory for dealing with small crystals. Since its installation, we have used it to collect data on over 4,000 compounds (roughly three a day). There have been about 150 people who have been involved in these experiments, including 37 women. We have also used this instrumentation to provide demonstrations for many nearby colleges and universities. Several high-school students have worked during summer internships. Well over 100 publications in referred journals have included work obtained with the Ultra diffractometer. The instrument has been used to explore a very diverse range of chemical inquiry. For instance, a high-effective anti-MRSA antibiotic isolated from deep-sea sponges was structurally characterized for the first time. From the structure a synthesis program was initiated. Recently published in JACS is the results of a long study on the structure of anti-freeze protein. The structure revealed that the protein inserts fingers into the crystalline structure of water preventing ice formation. A joint effort with CalTech in the area of carbon dioxide sequestration has led to the development of new transition-metal complexes that are highly effective in converting CO2 in stable derivative.
