Altering the Spectroscopy, Electronic Structure, and Bonding of Organometallic Curium(III) Upon Coordination of 4,4-bipyridine

Structural and electronic characterization of (Cp'3Cm)2(4,4'-bpy) (Cp' = trimethylsilylcyclopentadienyl, 4,4'-bpy = 4,4'-bipyridine) is reported and provides a rare example of curium-carbon bonding. Cp'3Cm displays unexpectedly low energy emission that is quenched upon coordination by 4,4'-bipyridine. Electronic structure calculations on Cp'3Cm and (Cp'3Cm)2(4,4'-bpy) rule out significant differences in the emissive state, rendering 4,4'-bipyridine as the primary quenching agent. Comparisons of (Cp'3Cm)2(4,4'-bpy) with its samarium and gadolinium analogues reveal atypical bonding patterns and electronic features that offer insights into bonding between carbon with f-block metal ions.