Reaction mechanisms of small-molecule activation by amidoditetrylynes R(2)N-EE-NR(2) (E = Si, Ge, Sn).

Abstract

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(††))(SiPr(i)3), where Ar(††) = C6H2{C(H)Ph2}2Pr(i)-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.