24
Research Methodology
Sample Preparation for
Evan’s Method Determination of Magnetic Susceptibility
1. Make a 0.01 M solution of Fe(porph)Cl in 10 mL volumetric using CHCl3as a solvent
2. Fill capillary tube to between 4-5 cm using labeled syringes.
3. Seal capillary in flame as demonstrated by instructor.
4. Place capillary in NMR tube.
5. Fill out tube with a mixture of CHCl3 and CDCl3 in about a 1:1 ratio. [The solvent should just
cover the capillary so that the tube floats freely from the sides of the NMR tube. The idea is that
it shouldn’t be like a sinker on the bottom of the NMR tube but it shouldn’t float off the bottom
too far either.]
6. Cap the NMR tube and run the experiment.
7. For imidazole: Make a 0.1 M solution by placing about 0.06 g of imidazole directly into the
remaining solution in your volumetric flask. Invert several times to ensure that it is all dissolved.
8. Repeat steps 2 through 6 above.