om7b00665_si_001.pdf (1.24 MB)
Metal–Silicon Triple Bonds: Access to [Si(η5‑C5Me5)]+ from SiX2(NHC) and its Conversion to the Silylidyne Complex [TpMe(CO)2MoSi(η3‑C5Me5)] (TpMe = κ3‑N,N′,N″‑hydridotris(3,5-dimethyl-1-pyrazolyl)borate)
journal contribution
posted on 2017-10-18, 19:40 authored by Priyabrata Ghana, Marius I. Arz, Gregor Schnakenburg, Martin Straßmann, Alexander C. FilippouA novel method to
prepare SiCp*2 (1) (Cp*
= C5Me5) is presented involving the reaction
of N-heterocyclic carbene (NHC)-stabilized SiII halides SiX2(NHC) (X = Cl, Br) with 2 equiv of
KCp*. This route is a superior alternative to the laborious, multistep
synthesis of 1 presently known and provides via the selective
protonolysis of 1 with [H(Et2O)2][B(C6F5)4] facile access to [Si(η5-Cp*)][B(C6F5)4] (2) in multigram scale and high yield. Reaction of 2 with
the tailored metallate Na[TpMeMo(CO)2(PMe3)] afforded the unprecedented silylidyne complex [TpMe(CO)2MoSi(η3-Cp*)] (3; TpMe = κ3-N,N′,N″-hydridotris(3,5-dimethyl-1-pyrazolyl)borate).
Single crystal X-ray diffraction and spectroscopic studies in combination
with quantum chemical calculations shed light on the unique bonding
situation of 3 featuring a delocalized Mo–Si bond
with partial triple bond character and a Cp* substituent, which is
η3-coordinated to silicon.