Oxidative Dissolution of Lanthanide Metals Ce and Ho in Molten GaCl 3 .

Gallium trichloride (GaCl 3 ) 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 °C in sealed vessels to maintain the liquid phase for GaCl 3 during the oxidizing reactions. The best results were obtained from reactions using 8 equiv of GaCl 3 to metal where the inorganic complexes [Ga][Ln(GaCl 4 ) 4 ] [Ln = Ce ( 1 ), Ho ( 2 )] could be isolated. Recrystallization of 1 and 2 employing fluorobenzene (C 6 H 5 F) produced [Ga(η 6 -C 6 H 5 F) 2 ][Ln(GaCl 4 ) 4 ] [Ln = Ce ( 3 ), Ho ( 4 )] where reversible η 6 coordination of C 6 H 5 F 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.