Ambiphilic reactivity is a fascinating topic in chemical reactions, attracting considerable interest because ambiphilic reagents can display properties of both nucleophilicity and electrophilicity. However, most of the previous attention has been focused on the characterization of the ambiphilic reactivity, whereas the origin is less understood. Here we carry out thorough density functional theory (DFT) calculations to probe the origin of the ambiphilic reactivity of the carbyne atom in osmapentalynes, observed previously in experiment. A series of osmium carbyne complexes ranging from acyclic to cyclic, non-conjugated to conjugated, non-aromatic to aromatic, unsubstituted to substituted were designed for comparable studies. Our results indicate that the origin of ambiphilic reactivity in osmapentalyne complexes should be attributed to an interplay of ring strain, aromaticity, and phosphonium substituent.

https://www.sciencedirect.com/science/article/abs/pii/S0022328X2100187X