Bisgermylene-Stabilized Stannylone: Catalytic Reduction of Nitrous Oxide and Nitro Compounds via Element-Ligand Cooperativity.

This study describes the synthesis, structural characterization, and catalytic application of a bis(germylene)-stabilized stannylone (). The reduction of digermylated stannylene () with 2.2 equiv of potassium graphite (KC) leads to the formation of stannylone as a green solid in 78% yield. Computational studies showed that stannylone possesses a formal Sn(0) center and a delocalized 3-c-2-e π-bond in the GeSn core, which arises from back-donation of the p-type lone pair electrons on the Sn atom to the vacant orbitals of the Ge atoms. Stannylone can serve as an efficient precatalyst for the selective reduction of nitrous oxide (NO) and nitroarenes (ArNO) with the formation of dinitrogen (N) and hydrazines (ArNH-NHAr), respectively. Exposure of with NO (1 atm) resulted in the insertion of two oxygen atoms into the Ge-Ge and Ge-Sn bonds, yielding the germyl(oxyl)stannylene (). Moreover, the stoichiometric reaction of with 1-chloro-4-nitrobenzene afforded an amido(oxyl)stannylene () through the complete scission of the N-O bonds of the nitroarene. Stannylenes and serve as catalytically active species for the catalytic reduction of nitrous oxide and nitroarenes, respectively. Mechanistic studies reveal that the cooperation of the low-valent Ge and Sn centers allows for multiple electron transfers to cleave the N-O bonds of NO and ArNO. This approach presents a new strategy for catalyzing the deoxygenation of NO and ArNO using a zerovalent tin compound.