Advanced Crystallography

NSF’s ChemMatCARS – Advanced Crystallography program is delicated to small-molecule single crystal X-ray diffraction.  The diffractometers are pre-aligned internally and can be moved into the beam when required. This flexibility allows us to take advantage of beam availability at short notice, a capability that has been used extensively in user experiments.

Recently we purchased new detectors, Pilatus3 X 2M (Si 1mm) and Pilatus3 X 1M (CdTe) detectors and expanded the crystallography program to a new setup in the 15-ID-D station where these detectors have been integrated with a Huber 3-circle diffractometer. The new equipment has been commissioned successfully (see picture below).

Available Techniques Include:

Resonance Diffraction/Diffraction Anomalous Fine Structure (DAFS)

Resonant diffraction/Diffraction Anomalous Fine Structure (DAFS) can be used to solve problems requiring identification of specific elements at given crystallographic sites. This application can only be used productively at synchrotron light sources.

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Structural Dynamics

Structural Dynamics is exploring molecular structure in “non-equilibrium states” and “real environment”.

  • Photo- or time-resolved crystallography uses the pulsed nature of the synchrotron source, together with its brilliance, to measure diffraction from samples that have been raised to excited states using laser light.
  • In-situ structural dynamics experiments use an in house design Environmental Control Cell (ECC) to study the confirmation of molecular structure changes under the real environmental conditions such as gas, vacuum, solutions and humidity.

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High-Resolution Charge Density Studies

High resolution charge density (HRCD)

  • Calculate Intermolecular interaction energy
  • Calculate electric static potential of molecule
  • Bonding information (topological analysis and source function analysis)
  • Characterization of the H-BOND
  • Determine the atomic charge using Atom in Molecular Theory(AIM)
  • Extract the “experimental wave function”

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Extreme Conditions

  • High-Pressure Studies:
    • Chemical high pressure crystallography (<10GPa) using Diamond Anvil Cell (HPDAC)
    • Measurement of compression
    • Characterization of phase transitions
  • Variable temperature (10K-600K)
  • Combined variable pressures and temperatures to characterize the phase diagram

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Microcrystallography

Microcrystallography provides:

  • Routine service crystallography on micro-crystals that cannot be measured elsewhere
  • Fast data collection (10 minutes) and good for air sensitivity compounds
  • Variable temperature (10k-600k)

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Experiment Specifications

  • Monochromators:
    • Si (111) : energy range, 5 – 32 KeV
    • Si (311) : energy range, 10 – 70 KeV
  • Max. Beam Size: 200 x 200 µm (3 x 1012 ph/s/0.1% bandwidth)
  • Min. Beam Size: 20 x 20 µm
  • Diffractometer Type:
    • 15-ID-B: Bruker D8 fixed-chi with 2θ detector rotation
    • 15-ID-D: Huber 3-circle diffractometer
  • Software: APEX3 suite, HPUtility, AmaskDectris
    • Pilatus3 X 2M (Si 1mm)
    • Dectris Pilatus3 X 1M (CdTe)
    • Bruker APEXII Detector
    • Vortex Detector
  • Sample Environment:
    • Cryojet N2 cold stream (90 – 300 K temperature range)
    • Open-flow liquid He cryostat (10 – 70 K temperature range)
    • Open-flow liquid N2 heat gun (300 – 700 K)
    • Diamond Anvil Cell (DAC)- with 85° and 120° opening
    • Environmental Control Cell (ECC)

NSF’s ChemMatCARS is a participating partner in the SCrAPS (Service Crystallography at the APS) Program. This program allows remote access to the micro-crystallography facility.

Crystallograpy Contact

Yu-Sheng Chen
(630) 252-0471
yushengchen@uchicago.edu

15 ID-D Station

Pilatus3 X 2M and Pilatus3 X 1M detectors

Crystallography Techniques