Structural determination of chemical compounds

ASM

 

The structural information can serve to:

  • Identify the compound (Unit cell determination may do the trick)
  • Verify the configuration and determine the geometry (interatomic distances and angles)
  • Determine the solid state conformation of the molecule
  • Obtain 3D coordinates (as a starting point to start calculations)
  • Analyse the intra and inter molecular interactions
  • Identify and analyse polymorphes (also possible in function of temperature)
  • Determine the absolute configuration (when certain conditions are met)

 

 
Profile of a good crystal

 cristal size: 0.1-0.5 mm (~ visible with the naked eye)
morphology: not so important, often single crystals are characterised by well defined edges
 

Often it is necessary to keep the crystals in solution as some crystals degrade outside the mother liquid. In doubtof the crystal stability, keep them in the crystallizing solvent.

 

Procedure to follow

Download the following document and send it back to Koen.Robeyns@uclouvain.be

 Analyse_Xray.docx

The responsible agrees to the analysis by signing a printed version of this document, which should accompany the sample.

 

Crystallization techniques