Reactivity of NHI-Stabilized Heavier Tetrylenes towards CO₂ and N₂O

A heteroleptic amino(imino)stannylene (TMS₂N)(I^tBuN)Sn: (TMS=trimethylsilyl, I^tBu=C[(N−^tBu)CH]₂) as well as two homoleptic NHI-stabilized tetrylenes, (I^tBuN)₂E: (NHI=N-heterocyclic imine, E=Ge, Sn) are presented. VT-NMR investigations of (I^tBuN)₂Sn: (2) reveal an equilibrium between the monomeric stannylene at room temperature and the dimeric form at −80 °C as well as in the solid state. Upon reaction of the homoleptic tetrylenes with CO₂, both compounds insert two equivalents of CO₂, however differing bonding modes can be observed. (I^tBuN)₂Sn: (2) inserts one equivalent of CO₂ into each Sn−N bond, giving carbamato groups coordinated κ²O,O’ to the metal center. With (I^tBuN)₂Ge: (3), the Ge−N bonds stay intact upon activation, being bridged by one molecule of CO₂ respectively, forming 4-membered rings. Furthermore, the reactivity of 2 towards N₂O was investigated, resulting in partial oxidation to form stannylene dimer [((I^tBuN)₃SnO)(I^tBuN)Sn:]₂ (6).