High-energy organometallic chemistry of curium: Laser ablation of Cm7O12 dispersed in polyimide

Gas-phase curium organometallic ions were synthesized by metal/polymer co-a blation. Vacuum laser ablation of a dilute dispersion of curium oxide in po lyimide resulted in several organocurium ions, evidently formed by nucleati on of Cm+ and various neutral polymer fragment radicals in the ablation plu me. The compositions and abundances of simple species such as CmC2+, CmC2H, and CmCN+, can be rationalized on the basis of the electronic structure a nd energetics of the curium ion, Cm+. The results for curium are in accord with a general thermochemical model previously employed to understand the o rganometallic speciation of preceding actinides. The identification of the above-specified species, along with several larger organocurium ions, exten ds the realm of organoactinide chemistry; specifically, it represents ident ification of a series of unique curium complexes which presumably incorpora te substantially covalent (sigma) Cm-C bonding. Also identified in the abla tion plume were small clusters incorporating two or three curium atoms. Sim ple clusters, such as Cm3O4+, reveal a trivalent, lanthanide-like character for curium and reflect the tendency toward bulk, solid-state chemical beha vior upon coalescence of only a few atoms. Finally, a notable ancillary obs ervation was the formation of several clusters in which C-2 evidently subst ituted sequentially for an O atom, revealing the pseudo-oxygen character of the dicarbide moiety.