Single crystal Xray diffraction

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Single crystal X-ray diffraction

• Dr Georgina Rosair
• Lab G.06/7 Ground floor below crush area

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Power of crystallography

• Crystals lt1mm long

• Complete 3D structure

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Crystal Growing Tips

• PURIFY your compound as much as is practically
  possible.
• FILTER the solution you will grow the crystals
  from.
• TEST THE CRYSTALS are they the RIGHT compound.
• Remove a few crystals to see if they lose solvent
  and examine them by infrared, NMR, etc.
• Grow the crystals SLOWLY and with the MINIMUM of
  vibration - a fridge is a good place.
• PERSEVERE - you may need to try several methods.

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Crystal growing methods

• Solvent diffusion
• Dissolve your compound in a solvent in which it
  is soluble and layer slowly on top a second
  solvent in which it is almost insoluble.
• The two solvents must be miscible. CH2Cl2/hexane
  is a common combination.
• NMR sample tubes have been used successfully.

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When you have crystals, what do you do?

• Completed forms into the pocket on the X-ray
  notice board outside G.07
• Contact number lab phone no. and HW email.
• LABELLED Samples in the analytical services
  fridge/freezer in the 200MHz NMR room (G21).

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X-ray crystallography and your research

• Structure solution and refinement
• Access to databases
• Pictures and tables for reports and papers

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Crystallographic results