A Stable Monomeric SiO₂ Complex with Donor–Acceptor Ligands

Abstract

Isolation of a monomeric SiO compound 3 as a stable donor-acceptor complex with two different ligands -a σ-donating ligand (pyridine, dimethylaminopyridine, N-heterocyclic carbene) and a donor-acceptor ligand (iminophosphorane)-is presented. The SiO complex 3 is soluble in ordinary organic solvents and is stable at room temperature in solution and in the solid state. Of particular interest, 3 remains reactive and can be used as a stable and soluble unimolecular SiO reagent.

Reversible CO2 Addition to a Si=O Bond and Synthesis of a Persistent SiO2–CO2 Cycloadduct Stabilized by a Lewis Donor–Acceptor Ligand

“…Thep hotolysis of 2 (l = 300 nm) under CO 2 pressure (4 bars) at À50 8 8Cl eads to the formation of the mixed SiO 2 -CO 2 cycloadduct 3 stabilized by an iminophosphorane D/Aligand (Scheme 1). Similar to the previously reported SiO 2dimer VIII, [12] in 3, the silanone moiety is well stabilized by the push-pull system of the iminophosphorane ligand. Indeed, in the 29 Si NMR spectrum, the signal corresponding to the silacarbonyl function appears as ad oublet at d = À69.1 ppm ( 2 J SiP = 14.9 Hz) in the same range as that of VIII (À74.0 ppm).…”

“…In the same vein, we have recently reported the synthesis of SiO 2 dimer VIII stabilized by an iminophophorane-type donor-acceptor (D/A) ligand as well as the first SiO 2 molecule IX stabilized by am ixed (donor) La nd (donoracceptor) D/A ligand system. [12] Thes tability of these molecules is mainly due to the peculiar effect of the D/A ligand, which efficiently binds the silanone (> Si = O) moiety. [12,13] Here,w er eport au nique RT reversible [2+ +2] cycloaddition between as ilanone function and CO 2 ,l eading to the first persistent SiO 2 -CO 2 cycloadduct of type IV stabilized by aD/A ligand.…”

“…[12] Thes tability of these molecules is mainly due to the peculiar effect of the D/A ligand, which efficiently binds the silanone (> Si = O) moiety. [12,13] Here,w er eport au nique RT reversible [2+ +2] cycloaddition between as ilanone function and CO 2 ,l eading to the first persistent SiO 2 -CO 2 cycloadduct of type IV stabilized by aD/A ligand. To the best of our knowledge,this is the first report describing the reversible addition of CO 2 on stable silanones.…”

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

“…[9] Furthermore,B aceiredo and Kato et al reported am onomeric SiO 2 complex using donor-acceptor interactions. [10] Herein, we report the remarkably facile access to the first isolable monomeric SiSe complexes as well as the first example of the structurally characterized monomolecular SiTe 2 species supported only by Lewis donors.…”

“…[9] Furthermore,B aceiredo and Kato et al reported am onomeric SiO 2 complex using donor-acceptor interactions. [10] Herein, we report the remarkably facile access to the first isolable monomeric SiSe complexes as well as the first example of the structurally characterized monomolecular SiTe 2 species supported only by Lewis donors. Tr eatment of the silylone-GaCl 3 adduct 1 [7] in acetonitrile with 1/8 molar equivalents of red selenium (Se 8 )a tr oom temperature for 3h leads to ay ellow solution, from which yellow crystals of (bis-NHC)Si( = Se)GaCl 3 2 were obtained in 65 %y ield (Scheme 2).…”