Reactivity of NHI-Stabilized Heavier Tetrylenes towards CO₂ and N₂O

A heteroleptic amino(imino)stannylene (TMS2N)((IBuN)-Bu-t)Sn: (TMS=trimethylsilyl, (IBu)-Bu-t=C[(N-Bu-t)CH](2)) as well as two homoleptic NHI-stabilized tetrylenes, ((IBuN)-Bu-t)(2)E: (NHI=N-heterocyclic imine, E=Ge, Sn) are presented. VT-NMR investigations of ((IBuN)-Bu-t)(2)Sn: (2) reveal an equilibrium between the monomeric stannylene at room temperature and the dimeric form at -80 degrees 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. ((IBuN)-Bu-t)(2)Sn: (2) inserts one equivalent of CO2 into each Sn-N bond, giving carbamato groups coordinated kappa O-2,O' to the metal center. With ((IBuN)-Bu-t)(2)Ge: (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 [(((IBuN)-Bu-t)(3)SnO)((IBuN)-Bu-t)Sn:](2) (6).