Although radiolytic re-oxidation of Cf 2+ is a significant hurdle to overcome, we have shown that the use of a more suitable reductant in the form of an Al/Hg amalgam is sufficient to reduce and maintain stability of the divalent state as well as prevent potential oxidants like water from Materials. The 249 CfCl3 used in this experiment was isolated as a solid residue following purification procedures. The 243 AmCl3 used in this experiment was acquired from an Am stock solution in 2M HCl. DyI2 (Sigma-Aldrich, 99%) was used as received. 18-crown-6 (Sigma-Aldrich, 99%) and tetrabutylammonium tetraphenylborate (Sigma-Aldrich, 99%) were used as received. Dicyclohexano-18-crown-6 (98%) was acquired as a mixture of cis-isomers from Sigma-Aldrich. The cis-syn-cis and cis-anti-cis isomers were separated from one another using the procedure established by Izatt and coworkers. Hydroiodic acid (contains no stabilizer, distilled, 57 wt. % in H2O, 99.99% trace metals basis, Sigma-Aldrich) was stored in a freezer at less than 0 °C until it was used. Ammonium hydroxide (28% NH3 in H2O, ≥ 99.99% trace metals basis, Sigma-Aldrich) was used as received. Diethyl ether (VWR, anhydrous ≥ 99.0% stabilized) was used as received for all manipulations on the benchtop. For manipulations in the glovebox, diethyl ether and acetonitrile (Sigma-Aldrich, anhydrous, 99.8%) were dried over sodium (Sigma-Aldrich, cubes, contains mineral oil, 99.9% trace metals basis) and benzophenone (Sigma-Aldrich, 99%)