Intrinsic reactivity of [OUCH]+ : Apparent synthesis of [OUS]+ by reaction with CS2.

RATIONALE: Building on our report that collision-induced dissociation (CID) can be used to create the highly reactive U-alkylidyne species [O=U≡CH]+ , our goal was to determine whether the species could be as an intermediate for synthesis of [OUS]+ by reaction with carbon disulfide (CS2 ).

METHODS

Cationic uranyl-propiolate precursor ions were generated by electrospray ionization, and multiple-stage CID in a linear trap instrument was used to prepare [O=U≡CH]+ . Neutral CS2 was admitted into the trap through a modified He inlet and precision leak valves.

RESULTS

The [O=U≡CH]+ ion reacts with CS2 to generate [OUS]+ . CID of [OUS]+ causes elimination of the axial sulfide ligand to generate [OU]+ . Using isotopically labeled reagent, we found that [OUS]+ reacts with O2 to create [UO2 ]+ .

CONCLUSIONS

[O=U≡CH]+ proves to be a useful reagent ion for synthesis of [OUS]+ , a species that to date has only been created by gas-phase reactions of U+ and U2+ . Dissociation of [OUS]+ to create [OU]+ , but not [US]+ , and the efficient conversion of the species into [UO2 ]+ , is consistent with the relative differences in U-O and U-S bond energies.