Nucleophilic Reactivity of a Nitride‐Bridged Diuranium(IV) Complex: CO2 and CS2 Functionalization

Thermolysis of the nitride-bridged diuranium (IV) complex Cs (μ-N) U (OSi (O (t) Bu) 3) 32 (1) showed that the bridging nitride behaves as a strong nucleophile, promoting N-C bond formation by siloxide ligand fragmentation to yield an imido-bridged siloxide/silanediolate diuranium (IV) complex, Cs (μ-N (t) Bu) (μ-O2 Si (O (t) Bu) 2) U2 (OSi (O (t) Bu) 3) 5. Complex 1 displayed reactivity towards CS2 and CO2 at room temperature that is unprecedented in f-element chemistry, affording diverse N-functionalized products depending on the reaction stoichiometry. The reaction of 1 with two equivalents of CS2 yielded the thiocyanate/thiocarbonate complex Cs (μ-NCS) (μ-CS3) U (OSi (O (t) Bu) 3) 32 via a putative NCS (-) /S (2-) intermediate. The reaction of 1 with one equivalent of CO2 resulted in deoxygenation and N-C bond formation, yielding the cyanate/oxo complex Cs (μ-NCO) (μ-O) U (OSi (O (t) Bu) 3) 32. Addition of excess CO2 to 1 led to the unprecedented dicarbamate product Cs (μ-NC2O4) U (OSi (O (t) Bu) 3) 32.