Taming Silicon Congeners of CO and CO2: Synthesis of Monomeric SiII and SiIV Chalcogenide Complexes

Angewandte Chemie - International Edition

5 years ago

Taming Silicon Congeners of CO and CO2: Synthesis of Monomeric SiII and SiIV Chalcogenide Complexes

Martin Kaupp, Matthias Driess, Alexander Burchert, Robert Müller, Shenglai Yao, Caspar Schattenberg, Yun Xiong

The synthesis of the unprecedented monomeric SiII selenide complex (bis-NHC)Si=SeGaCl3 2 (bis-NHC=bis-N heterocyclic carbene, H2C[{NC(H)=C(H)N(Dipp)}C:]2, Dipp=2,6-iPr2C6H3), bearing the elusive SiSe ligand as a heavy CO homologue by the reaction of the silylone–GaCl3 adduct (bis-NHC)SiGaCl3 1 with elemental selenium in acetonitrile, is reported. The similar conversion of 1 with excess selenium conducted in THF afforded the SiSe2 complex (bis-NHC)Si(=Se)SeGaCl3 3. Remarkably, the reaction of 1 with Te=P(nBu)3 as a gentle Te transfer reagent led to the isolation of the monomeric SiTe2 complex (bis-NHC)SiTe2 4, the first structurally characterized Lewis acid free heavy CO2 homologue complex. The isolated compounds 2, 3, and 4 have been fully characterized, including single-crystal X-ray diffraction analyses. Their electronic structures and spectroscopic data have also been studied by quantum-chemical calculations. Heavy members: Unprecedented heavy CO and CO2 homologue complexes are reported. Bis-NHC–GaCl3-stabilized silylone 1 affords the first divalent SiX complex 2 (see scheme) and the SiX2 complexes 3 and also 4, the first structurally characterized heavy CO2 homologue complex without Lewis acid stabilization.

Publisher URL: http://onlinelibrary.wiley.com/resolve/doi

DOI: 10.1002/anie.201700530