X-RAY DIFFRACTION

X-ray crystallography aims for the definitive establishment of geometric structure, giving researchers an indispensable means to constitute structure-function relationships. The recent advances in detector technology for this application has resulted in the ability to acquire complete data sets in hours rather than days. The speed and ease of use of this type of modern equipment make it now feasible and cost effective to use crystallographic structure determination as a routine characterization tool.

It is recommended that X-ray structure determination be carried out whenever any of the following is desired:

  • Geometrical or conformational information

  • Inter or intra molecular bonding and non-bonding interactions

  • Thermal motion of rigid groups

  • Absolute configuration, if an element heavier than Si is present or if one chiral centre is already known in a molecule

The X-ray laboratory is a full service facility which provides range of services associated with the structure analysis of small molecule single crystals. These services include:

  • Determination of unit cell parameters, crystal system and space group

  • Data collection, structure solution and refinement

  • Analysis of the structural results ( hydrogen bonding, Intermolecular interactions, etc)

  • Full report of structure analysis with data tables, cif file and molecular illustrations

All of the above services have nominal fee. Please consult with Saeed Khan for charges.

Sample Submission

For single crystal analysis submit your sample and a fully completed sample submission form (copies are also available in the lab) to the J.D. McCullough X-ray Laboratory at 1416 Molecular Science Building.

Sample submission form

Your sample will be analyzed on a first come first serve basis. Normal turn around time is 2-3 days. For powder samples no sample submission form is required. Individuals from other on-campus departments at UCLA must bring a completed form P-39 or establish a recharge account with the Chemistry Department. Outside users should mail properly sealed samples to:

Saeed Khan

1412 Molecular Science Building

Dept. of Chemistry & Biochemistry

University of California at Los Angeles

Los Angeles, CA 90095-1569

It is advisable to:

  • Keep crystals in mother liquor.

  • Use small vials. If crystals grow in NMR tube, submit the tube as it is, do not try to remove the crystals.

  • Submit more than one vial of crystals, for air sensitive or unstable compounds.

  • Make prior arrangements with the lab director for compounds which are unstable and degrade quickly. This way we can put you on a priority list and analyze the compound when the crystals are fresh.

  • Verify by some other analysis (NMR, MS, etc) that you are not submitting a starting material or an unwanted compound. Please note that few perfect crystals in a mass of trash may not represent the bulk of sample.


Instrumentation

Panalytical X'Pert Pro X-ray Powder Diffractometer

Installed in 2004

Bragg-Brentano and Parallel Beam Optics

Incident and Diffracted Beam Mirrors

Computer Controlled Slits

X’celerator RTMS Scanning Detector

Sealed Proportional Detector

High Temperature Stage up to 1000C

Bruker DUO ApexII CCD-single crystal X-ray Diffractometer

Installed in 2013

Quazar multilayer Microfocus Cu

Triumph Monochromator Mo-X-ray source

Low temperature device

APEX software suite

Bruker D8 Discover Powder X-ray Diffractometer

Installed in 2006

Push Plug Gobel Mirror

9- Position Sample Stage

Vantac Detector for FastSimultaneous Recording

Rotary Absorber

Zeiss Stereo Discover V12 Microscope

Xray-Instruments