|
Small-Molecule
X-Ray Crystallography Lab |
|
|
|
This lab uses diffraction methods to determine high-precision three-dimensional solid-state structures of crystalline organic, inorganic and biological molecules and to identify polycrystalline materials. We are part of the Molecular Structures Group (MSG) at KU, a campus wide facility encompassing NMR, Mass Spectrometry, X-ray Crystallography (large and small molecule), Biochemical Services, and Molecular Graphics and Modeling Laboratories. Small-molecule single crystals can be studied with molybdenum or copper radiation. The MSG X-ray Crystallography Laboratory has a Bruker SMART APEX single-crystal diffractometer that is equipped with a Mo sealed tube x-ray source, a graphite monchromator, MonoCap collimator and a SMART APEX charge-coupled device (CCD) area detector. A new high-powered Bruker MicroSTAR high-brilliance microfocus Cu rotating anode X-ray generator was installed in June 2010. This system is located in the Protein Structure Lab on KU’s West Campus and has two CCD detectors with HELIOS or HELIOS MX high-brilliance multilayer optics. One detector has a 4K PLATINUM 135 CCD detector mounted on a 4-circle Kappa goniometer and the other has an APEX II CCD detector mounted on a 3-circle goniometer. Another Bruker-Nonius diffractometer will be available in the fall of 2010. This system will have a Bruker SMART 6000 CCD area detector mounted on a 3-circle goniometer with a Bruker-Nonius FR591 Cu rotating anode x-ray source and Montel mirror optics. All four single-crystal diffractometers have Oxford Cryostream Low Temperature units and can be used for small-molecule single-crystal studies. The three CCD detectors with a Cu rotating anode x-ray source can also be used for macromolecular single-crystal studies as well as qualitative powder diffraction studies. The lab also includes a Bruker D8 powder diffractometer that uses a sealed tube Cu x-ray source and is equipped with a 1/4 circle Huber cradle that can be used to analyze the textures of materials. Most single-crystal studies are conducted at a temperature of 100K but studies can be performed at any temperature between room temperature and 80K. The single crystal small-molecule studies range from the use of x-ray crystallography as a routine analytical tool for identifying reaction products to detailed studies of bonding subtleties in complex inorganic molecules and hydrogen-bonded organic species. Although the lab always prefers to work with single-domain specimens, it routinely determines structures for twinned samples with multiple domains when single-domain crystals cannot be obtained. Final structural results can usually be obtained within 24 hours of the start of data collection. |
||
| Contact webmaster with comments about this web site. | ||
