Synthesis of electron-rich metal-substituted silylenes and their potential in small molecule bond activation

与环状硅烯相比，非环状硅烯具有更强的活性，这是因为它们的单重态-三重态能垒降低，而且它们在小分子活化反应中的潜在应用，如H2、CO或CO2，近年来已被证明。尽管这些研究显示了一些与众所周知的过渡金属络合物的化学相似之处，但对于硅烯来说，最核心的反应之一--通过与CO反应形成金属羰基络合物--是未知的。最近，我们通过金属取代的硅烯[L1(BR)Ga]2Si：与CO反应，成功地合成了第一个室温稳定的硅烯羰基配合物[L1(BR)Ga]2Si-CO6。在本研究项目中，我们将尝试推广金属取代硅烯[L(X)M]2Si的合成，并研究13diyles Lm以及起始硅试剂SiX4(X=Cl，BrI，NR2，OR)对反应途径的影响以及所得硅烯的稳定性。我们将进一步研究[L1(BR)Ga]2Si：和[L1(BR)Ga]2Si-CO6以及化合物5在小分子活化反应中与H_2、CO、CO_2、烯烃C_2R_4、烷基C_2R2、CN多键和E-H主族元素氢化物的反应潜力。原位核磁共振波谱研究和计算计算应该提供对反应的机理理解和对所得到的络合物的电子性质的详细理解。

Acyclic silylenes are typically more reactive compared to their cyclic congeners due to their reduced singlet-triplet energy barrier and their promising potential for small molecule activation reactions, i.e. H2, CO or CO2, has been demonstrated in recent years. Even though these studies showed some parallels to the well-known chemistry of transition metal complexes, one of the most central reaction, the formation of metal carbonyl complexes by reaction with CO, is unknown for silylenes. We recently succeeded in the synthesis of the first room temperature-stabile silylene carbonyl complex [L1(Br)Ga]2Si–CO 6 by reaction of the metal substituted silylene [L1(Br)Ga]2Si: with CO. In this research project, we will try to generalize the synthesis of metal-substituted silylenes [L(X)M]2Si: and study the influence of the group 13 diyles LM as well as the starting silicon reagents SiX4 (X = Cl, Br, I, NR2, OR) on the reaction pathway as well as the stability of the resulting silylenes. We will furthermore investigate the potential of the silylene [L1(Br)Ga]2Si: and the carbonyl complex [L1(Br)Ga]2Si–CO 6 as well as of compound 5 in small molecule activation reactions with H2, CO, CO2, olefines C2R4, alkines C2R2, CN multiple bonds and E-H main group element hydrides. In situ NMR spectroscopic studies and computational calculations should provide a mechanistical understanding of the reaction and a detailed understanding of the electronic nature of the resulting complexes.