Oxidative Dissolution of Lanthanide Metals Ce and Ho in Molten GaCl3.

Gallium trichloride (GaCl3) was used as a solvent for the oxidative dissolution of the lanthanide (Ln) metals cerium (Ce) and holmium (Ho). Reactions were performed at temperatures above 100 degrees C in sealed vessels to maintain the liquid phase for GaCl3 during the oxidizing reactions. The best results were obtained from reactions using 8 equiv of GaCl3 to metal where the inorganic complexes [Ga][Ln(GaCl4)(4)] [Ln = Ce (1), Ho (2)] could be isolated. Recrystallization of 1 and 2 employing fluorobenzene (C6H5F) produced [Ga(eta(6)-C6H5F)(2)][Ln(GaCl4)(4)] [Ln = Ce (3), Ho (4)] where reversible eta(6) coordination of C6H5F to [Ga](+) was observed. All complexes were characterized through elemental analysis (F and Cl), IR and UV-vis-near-IR spectroscopies, and both solution and solid-state NMR techniques.