A Dimer of Silaisonitrile with Two‐Coordinate Silicon Atoms

Abstract

A specialty of silicon: A stable dimeric silaisonitrile (ArNSi:)2 (see picture; Ar=2,6‐bis(2,4,6‐triisopropylphenyl)phenyl) was prepared by the reduction of dichlorosilaimine IPr⋅Cl2SiNAr with KC8. The dimer is the first base‐free disilylene with two‐coordinate silicon atoms; reaction with trimethylsilyl azide affords the first bis(silaimine) (ArNSiNSiMe3)2 with three‐coordinate silicon atoms.

Preparation of Stable Low‐Oxidation‐State Group 14 Element Amidohydrides and Hydride‐Mediated Ring‐Expansion Chemistry of N‐Heterocyclic Carbenes

“…[5a] The Si À N bond length in 1 (1.765(2) ) is marginally longer than the Si À N bond lengths present in the Roesky dimeric silaisonitrile, {[(2,4,6-iPr 3 C 6 H 2 ) 2 C 6 H 3 ]NSiD} 2 (1.756(1) average). [16] Similarly, the EÀN (E= Ge or Sn) bond lengths in 2 and 3 are 1.900(3) (average) and 2.1142 (16) , respectively, and are within the range that is expected for single bonds. For comparison, the Ge À N bonds in the acyclic Ge II bisamide (Ar''NH) 2 GeD (Ar'' = 2,6-(2,4,6-Me 3 C 6 H 2 ) 2 C 6 H 3 ) are 1.896(2) , whereas (2).…”

“…For comparison, the Ge À N bonds in the acyclic Ge II bisamide (Ar''NH) 2 GeD (Ar'' = 2,6-(2,4,6-Me 3 C 6 H 2 ) 2 C 6 H 3 ) are 1.896(2) , whereas (2). Compound 3: SnÀC(1) 2.3220 (19), SnÀ N(3) 2.1142 (16), SnÀCl(1) 2.4898 (6), N(3)ÀC(51) 1.403(2); Cl-Sn-N(3) 95.21(5), Cl-Sn-C(1) 89.59(5), N(3)-Sn-C(1) 94.83 (6), Sn-N(3)-C(51) 116.53 (12). an average Sn À N separation of 2.101(3) exists in the tin congener (Ar''NH) 2 SnD.…”

Facile Access to an NHC‐Coordinated Silicon Ring Compound with a Si=N Group and a Two‐Coordinate Silicon Atom

“…The Si4=N7 (1.625(2) Å) bond length is at the upper range of those found in silaimines (1.550–1.611 Å) . Silaimines were synthesized by the addition of azides to a silylene,–,, or more recently by the addition of SiCl 4 to an NHC‐coordinated amidochloro‐substituted silylene or SiI 4 to an N(SiMe 3 ) 2 and amidinato‐substituted silylene . In addition, unsaturated compounds such as isonitriles and acetylenes reacted with NHC‐coordinated amidochloro‐substituted silylenes to yield silaimines ,.…”

A Tetrasilicon Analogue of Bicyclo[1.1.0]but‐1(3)‐ene Containing a Si=Si Double Bond with an Inverted Geometry

“…Figure 2shows the molecular structure of 1,asdetermined by single-crystal XRD analysis at 100 K. Them olecule is located on acrystallographic inversion center at the middle of the bridgehead Si atoms (Si1 and Si1*), which reflects the planar central Si 4 skeleton. TheSi1 À Si1* distance in 1 [2.4716-(11) ]i ss ubstantially longer than hitherto reported Si = Si double bonds in structurally similar cyclotrisilene E [2.1429-(5) ] [14] and the bridgehead SiÀSi single bond in bicyclo-[1.1.0]tetrasilanes F [2.3600(15)-2.373 (3) ], [15] but considerably shorter than those of cyclic disilylene G [2.5666 (9) ], [16] pentasila [1.1.1]propellane H [2.636 (1) ] [5i] (Figure 3), and related clusters [2.4976(9)-2.7076 (8) ]. [5j, 17] This feature stands in sharp contrast to the fact that the bridgehead GeÀ Ge bond in C [2.8714 (11) (1)-2.3744(7) ].…”