Reaction mechanisms of small-molecule activation by amidoditetrylynes R₂N-EE-NR₂ (E = Si, Ge, Sn)

The calculated reaction profiles using density functional theory at the BP86/TZVPP level for the reaction of small molecules with amidoditetrylynes R₂N-EE-NR₂ (E = Si, Ge, Sn) are discussed. Four projects are presented that feature the virtue of cooperation between theory and experiment. First, the calculated reaction paths for hydrogenation of the model systems (Me₂N)EEL(NMe₂) (E = Si, Ge, Sn), which possess E-E single bonds, are examined. The results for the germanium model systems are compared with hydrogenation of the real system L^†GeGeL ^† where L^† = Nar*(SiMe₃) (Ar* = C₆H₂{C(H)Ph₂}₂Me-2,6,4) . The second project introduced the multiply bonded amidodigermyne L ^††GeGeL^††, which carries the extremely bulky substituents L^†† = N(Ar ^††)(SiPrⁱ₃), where Ar ^†† = C₆H₂{C(H)Ph ₂}₂Prⁱ-2,6,4. The theoretical reaction profile for dihydrogen addition to L^††GeGeL ^†† is discussed. Hydrogenation gives L ^††(H)GeGe(H)L^†† as the product, which is in equilibrium with the hydrido species Ge(H)L ^††. The latter germanium hydride and tin homologue Sn(H)L^†† were found to be effective catalysts for hydroboration reactions, which is the topic of the third project. Finally, the calculated reaction course for the reduction of CO₂ to CO with the amidodigermyne L^†GeGeL^† is discussed.