Different Reactivity of As₄towards Disilenes and Silylenes

Abstract

The activation of yellow arsenic is possible with the silylene [PhC(NtBu) SiN(SiMe ) ] (1) and the disilene [(Me Si) N(η -Me C )Si=Si(η -Me C )N(SiMe ) ] (3). The reaction of As with 1 leads to the unprecedented As cage compound [(LSiN(SiMe ) ) As ] (2; L=PhC(NtBu) ) with an As nortricyclane core stabilized by arsasilene moieties containing silicon(II)bis(trimethylsilyl)amide substituents. In contrast, the compound [Cp*{(SiMe ) N}SiAs] (4) containing a butterfly-like diarsadisilabicyclo[1.1.0]butane unit is formed by the reaction of As with the disilene 3. Both compounds were characterized by single-crystal X-ray diffraction analysis, NMR spectroscopy, and mass spectrometry. The reaction outcomes demonstrate the different reaction behavior of yellow arsenic (As ) compared to white phosphorus (P ) in the reactions with the corresponding silylenes and disilenes.

Where silylene–silicon centres matter in the activation of small molecules

“…101 By contrast, the reaction of 149 with As 4 in toluene leads to the formation of the unprecedented As 10 cage compound 151 featuring a nortricyclane core. 102 The Si-As bond of the exocyclic substituents in 151 can be regarded as an elongated double bond or an ion compound with the negative charge localised at the As atom and the positive charge over both N atoms in the heterocycle.…”

Versatile Tautomerization of EH2-Substituted Silylenes (E = N, P, As) in the Coordination Sphere of Nickel

“…The solid state structure of 12 (Figure ) contains a bridging Si–H···Li contact, leading to tetrahedral geometry at Li1 and a rather acute Si–As–Li angle of 68.63(1)°. The high charge density at As1, due to its metalation, leads to a highly contracted Si–As bond length in 12 (δ = 2.2402(8) Å), which is essentially as short as the majority of “free” SiAs bonds, including the 1,2-dihydrosilaarsene D reported by us previously (d­(Si–As) = 2.214 Å). , Indeed, the Si–As bond in 12 is considerably shorter than that in closely related 11 , testament to the charge separation in the As–Li bond relative to the As–Ni bond. Despite this, the Ni–As bond in 12 is longer than that in 11 , at 2.4015 Å, with a similar lengthening observed for the Ni–Si bond (d­(Si1–Ni1) = 2.233(1) Å).…”

Reactivity of (TMS)2N(η1-Cp*)Si═Si(η1-Cp*)N(TMS)2 toward the Halides of Groups 13–15

“…1 was later reproduced by Roesky and co-workers in 68% yield by utilizing (Me 5 C 5 )­SiHCl 2 precursor with KN­(TMS) 2 in a single-step procedure . This modified procedure of 1 boosted further exploration of its reactivity and led to the isolation of Si 2 O 2 and Si 2 S 2 ring compounds along with P 4 and As 4 activation. − Nonetheless, the reactivity of 1 is only limited to this handful of examples (Chart ), but they are different than the usual disilenes.…”