Tips on Using MicroMounts™ for Small Molecule and Inorganic Crystallography
MicroMounts™ are also extremely convenient for mounting crystals - and especially tiny crystals - of other organic and inorganic substances for crystallography.
Select a mount with a sample aperture size slightly smaller than the crystal size. This will help minimize background X-ray scatter.
Cut the pin (if necessary) to a desired length using our pin cutters or other cutters designed for spring-temper steel. The center-to-center distance between black lines on the pin is 2 mm. Use the millimeter scale on the top of the box to help cut it to the desired length, lining up the end of the pin with the right end of the scale.
Insert the pin into a standard goniometer base using a small amount of, e.g., Dow-Corning #976V high vacuum grease or Duco Cement hold it in place. For easier handling, attach the base to a magnetic rod. The pin can also be inserted into a 0.7 mm mechanical pencil.
Scoop or place the crystal into the sample aperture. The crystal can be held in place using a tiny amount of, e.g., contact adhesive, applied using a small (25 gauge or smaller) tungsten or molybdenum wire. Alternatively, a small drop of ethyl cellulose dissolved in ethyl acetate can be placed on the crystal/mount and allowed to evaporate, providing a thin polymer film that holds the crystal in place.
To make the ethyl cellulose/ethyl acetate mixture:
Mix 300 micrograms ethyl cellulose in 75 ml of ethyl acetate.
Slowly heat the mixture (with boiling chips) to the boiling point in a fume hood, and boil gently for 5 minutes. Let cool to room temperature. Be sure to read warnings about each component. Ethyl acetate can be dangerous at temperatures above 77 C.
Both components are available from many US suppliers.
- ethyl acetate:
J.T. Baker (1-800-582-2537)
- ethyl cellulose: Be sure to specify powder or granule form
-
IslandGroup 516-746-2100
Rotuba 908-486-1000