This issue is circumvented by growing crystals over the amalgam itself via vapor diffusion of a 1:1 mixture of diethyl ether and pentane into the mother liquor at 0 ºC. Red-brown crystals of Cf(18-crown-6)I2 primarily grow (in surprisingly high yield) between the amalgam and the wall of the glass vial as shown in Figure . Even with this crystal growth method where a large excess of reductant is always present, these samples degrade at room temperature, 0 ºC, and even at -173 ºC in less than 16 hours because of radiolytic effects.