Luminescence processes in [Tb.cntnd.bpy.bpy.bpy]3+ cryptate: a low-temperature solid-state study

The luminescence properties of solid [Tb.cntnd.bpy.bpy.bpy]3+, [La.cntnd.bpy.bpy.bpy]3+, and [Na.cntnd.bpy.bpy.bpy]+ are reported for temps. down to 4.2 K. The 2,2'-bipyridine phosphorescence in the case of the La3+ and Na+ cryptate is quenched by energy migration to killers. In the case of Tb3+, however, efficient energy transfer from the cryptand to Tb3+ takes place up till 100 K. At that temp. migration competes with energy transfer to Tb3+, reducing the Tb3+ luminescence output. The rates of the processes involved are detd. as accurately as possible. A comparison is made with the same cryptate mols. in soln. [on SciFinder(R)]