Dinuclear and tetranuclear group 10 metal complexes constructed from linear tetrasilane comprising both Si-H and Si-Si moieties

The activation of Si-H bonds and/or Si-Si bonds in organosilicon compounds by transition-metal species plays a crucial role for the production of functional organosilicon compounds. Although group-10-metal species are frequently used to activate Si-H and/or Si-Si bonds, so far, systematic investigation to clarify the preferences of these metal species with respect to the activation of Si-H and/or Si-Si bonds remain elusive. Here, we report that platinum(0) species that bear isocyanide or N-heterocyclic-carbene (NHC) ligands selectively activates the terminal Si-H bonds of the linear tetrasilane Ph-2(H)SiSiPh2SiPh2Si(H)Ph-2 in a stepwise manner, whereby the Si-Si bonds remain intact. In contrast, analogous palladium(0) species are preferably inserted into the Si-Si bonds of the same linear tetrasilane, whereby the terminal Si-H bonds remain intact. Substitution of the terminal hydride groups in Ph-2(H)SiSiPh2SiPh2Si(H)Ph-2 with chloride groups leads to the insertion of platinum(0) isocyanide into all Si-Si bonds to afford an unprecedented zig-zag Pt-4 cluster. Group 10 metal species are commonly used to activate Si-H and Si-Si bonds, but their preferred reactivity towards Si-H vs Si-Si activation is poorly understood. Here, Pt(0) species are shown to selectively activate the Si-H bonds in a linear tetrasilane, whereas Pd(0) preferentially activates the Si-Si bonds.

Automated summary

The activation of Si-H and/or Si-Si bonds in organosilicon compounds by transition-metal species is important, but the preferences of group-10-metal species in this activation are not well understood. Here, it is shown that Pt(0) species selectively activate the Si-H bonds in a linear tetrasilane, while Pd(0) preferentially activate the Si-Si bonds.