Disilene-Silylene Interconversion: A Synthetically Accessible Acyclic Bis(silyl)silylene

Silylenes have recently shown fascinating reactivity patterns, which are normally observed almost exclusively for transition-metal complexes. In particular, very reactive representatives are considered to be promising candidates, which may become powerful and economical alternatives for catalytic applications in the future. Here, we present the isolation of an equilibrium mixture consisting of a tetrasilyldisilene and its isomeric bis(silyl)silylene, the first isolable silylene of this type. Preliminary investigations demonstrate the extreme inherent reactivity via facile small-molecule activation even under very mild conditions. Thus, the oxidative addition of challenging targets such as H₂ and NH₃ was achieved. In addition, by synthesizing donor-stabilized bis(silyl)silylenes we gained further insights into the disilene-silylene rearrangement by 1,2-silyl migrations. Thorough theoretical calculations support the observed experimental results.