The C-N coupling reaction of bimetallic cations [MAu(CH)]⁺ (M=Pt, Ir, Os) with NH₃

Bimetallic methylidyne cluster cations such as [MAu(CH)]⁺ (M=Pt, Ir, Os), featuring the combination of a less reactive (Au) and a more reactive (M) metal centers, exhibit very different reactivities with NH₃. Density functional calculations confirm the direct CN coupling in all clusters, with the main products of PtAu/[CH₂NH₂]⁺ in the Pt system and [MAu(CNH₂)]⁺ (M=Ir, Os)/H₂ in the Ir and Os systems. Furthermore, for the first time, a feasible minor product reaction path leading to the direct formation of HCN has been located in both the Ir and Os systems. The great potential of regulating reaction pathways by designing bi- or multi-metallic catalysts is presented.