Conjugated systems with Si=Si Double Bonds
Weidenbruch et al. contributed pioneering work with the isolation of the first example of a compound with conjugated Si=Si double bonds, a tetrasilabutadiene prepared via the oxidative dimerization of the presumed intermediate, disilenide 1.
With the disilenide 1 now available as an isolated compound we have shown that the Si=Si moiety can also be transferred to aromatic substrates leading to phenylene bridged tetrasiladienesmeta-8 and para-8. The effective conjugation was proven by the pronounced red color ofpara-8 as opposed tometa-8, which exhibited the usual yellow color of isolated SI=Si-bonds. The electrochemistry of both compounds was investigated in collaboration with the group of Frank Breher (KIT Karlsruhe, Germany) corroborating this assertion.
We are actively exploring the scope of the Si=Si transfer reaction in order to access larger systems with multiple heavier double bonds in conjugation through extended organic linkers.