Bis[N,N′‐diisopropylbenzamidinato(−)]silicon(II): A Silicon(II) Compound with Both a Bidentate and a Monodentate Amidinato Ligand

Abstract

Die reduktive Eliminierung von HCl aus dem λ6‐Silicium(IV)‐Komplex 1 führt zur λ3‐Silicium(II)‐Spezies 2, einem neuen Typ von donorstabilisiertem Silylen. Die Reaktionen von 2 mit [W(CO)6] oder I2 ergeben den λ5‐Silicium(II)‐Komplex 3 bzw. den λ6‐Silicium(IV)‐Komplex 4.

Donor‐Stabilized Silylenes with Guanidinato Ligands

“…The isotropic 29 Si chemical shifts of 3 – 6 in the solid state and in solution (Table 1) are similar (Δ δ 29 Si = 0.3–8.1 ppm), indicating that these compounds also exist in solution. The isotropic chemical shifts of guanidinatosilicon(II) complex 4 [solid state: δ = –20.6 ppm; solution (C 6 D 6 ): δ = –25.6 ppm] and the related amidinatosilicon(II) complex 2 [solid state: δ = –15.4 ppm; solution (C 6 D 6 ): δ = –31.4 ppm]2g differ significantly. The same holds true for the difference in chemical shift between the solid state and solution ( 2 , Δ δ 29 Si = 16.0 ppm; 4 , Δ δ 29 Si = 5.0 ppm), which is much more pronounced for 2 .…”

“…To overcome this problem, we used a totally different strategy for the preparation of 4 and 6 , a reductive HCl elimination of six‐ and five‐coordinate silicon(IV) complexes 3 and 5 , respectively (Scheme ). This strategy has also been successfully used for the synthesis of the amidinatosilicon(II) complexes 1 and 2 2a,2g. As amidinato and guanidinato ligands differ in their electronic properties, the title compounds 4 and 6 were very attractive targets to be synthesized and to be studied for their reactivity, especially in comparison with related silylenes that contain amidinato ligands.…”

Recent Advances in Silylene Chemistry: Small Molecule Activation En-Route Towards Metal-Free Catalysis

“…Since the pioneering work of West and Denk et al, a large number of N-heterocyclic silylenes (NHSis) have made their appearance in the literature (Fig. 2) [2][3][4][5][6][7][8][9][10][11][12][13][14]. A rich and diverse chemistry has been developed for many of these NHSis, in particular NHSis 1-8.…”

Stable Five‐Coordinate Silicon(IV) Complexes with SiN4X Skeletons (X=S, Se, Te) and SiX Double Bonds

“…[1] Future studies have to evaluate the chemical reactivity of the Si=X double bonds of 11 a-c and the synthetic potential of these compounds for the chemistry of higher-coordinate silicon. l 5 Si IV ).…”