Laboratory textbooks and manuals contain very few high quality photographs, if any, to reinforce the narrative. Also, they do not show what happens when students fail to follow their instructions on techniques. Thus, students may not understand the need to follow instructions. This photographic presentation surveys a range of techniques including single solvent, mixed solvent and vapor phase diffusion crystallizations, together with the errors associated with them. Fundamental methods are demonstrated by crystallizations using Pd (II) octaethylporphyrin, Zn(II) octaethylporphyin, acetamide and 1,2,3,4-tetraphenylnapthalene. Samples were chosen to illustrate different facets of the techniques and phenomena such as the generation of different crystal forms. Common errors including incorrect solvent selection, misuse of decolorizing charcoal, improper hot filtration are shown. In addition to reinforcing the need to follow experimental technique, the galleries are useful in assisting students to diagnose the cause of any mistakes that they have made.

Development of a photographic gallery of crystallization techniques and the errors associated with them

245th National Meeting (2013)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.