Preparation of Dy (18-crown-6)I2. In a glovebox under an argon atmosphere, a 20 mL glass scintillation vial was charged with 20.0 mg of DyI2. Then, 3 mL of cold (-30 °C) DME was added to the vial and swirled to encourage dissolution of the DyI2. The dissolution process was slow, and the solution began to turn a shade of dark green. The reaction vial was stored in a glovebox freezer at -30 °C to maintain stability of Dy 2+ in solution. Every 10 minutes, the vial was removed from the freezer and a metal spatula was used to grind the remaining solid to encourage further dissolution of the DyI2. The solution was then gently swirled and replaced in the freezer for another 10-minute period. This was repeated until all solids dissolved, resulting in a dark green solution.