Metal‐Free Activation of EH₃ (E=P, As) by an Ylide‐like Silylene and Formation of a Donor‐Stabilized Arsasilene with a HSiAsH Subunit

Abstract

Twice, and faster: Reaction of the zwitterionic silylene 1 with AsH3 occurs stepwise at ambient temperature to give the first crystalline, donor‐stabilized arsasilene 3 via its 1,1‐addition product (silylarsane 2). In contrast, the activation of PH3 by 1 merely leads to the phosphorus analogue of 2. The strikingly different metal‐free activation of the series of Group 15 hydrides EH3 (E=N, P, As) by 1 was rationalized with DFT calculations.

Triamidoamine uranium(IV)–arsenic complexes containing one-, two- and threefold U–As bonding interactions

“…Complex 3c, as a metal-stabilized terminal parent arsinidene complex, has no precedent; examples in the condensed phase are rare and usually involve μ 2 -or μ 3 -AsH bridging modes to d-block metals 59,60 because of its sterically unencumbered nature and to stabilize the formal charge accumulation at arsenic. Reports of a terminal M=AsH unit are restricted to one example in the p-block in an arsasilene complex with a HSi=AsH subunit 61 .…”

“…The (AsH) 2− arsinidene has been observed in the gas phase since the 1960s 58 , but examples in the condensed phase are limited to μ 2 -or μ 3 -bridging modes to d-block metals to stabilize the charge accumulation at arsenic 59,60 . Reports of a terminal M=AsH unit in the p-block are restricted to one example in a silylidenearsane/arsasilene with a HSi=AsH subunit 61 . The (As) 3− arsenido is rare in a molecular context and only four terminal arsenidos with group 5 and 6 d-block metals are known [62][63][64] .…”

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

“…(b) ORTEP representation of 43 thermal ellipsoids drawn at 50% probability level. The H atoms have been omitted for clarity activation of other small molecules such as ammonia, hydrazines and hydrazone [18,19], resulting in 26-29, respectively (Scheme 3) [20,21]. Strikingly, NHSi 3 has even been shown to activate alkynes (Scheme 4) [22,23].…”

“…This is potentially a result of its zwitterionic nature with À affords the unique cationic silyliumylidene 20 through protonation of the Si(II) centre [16,17]. Moreover, the reaction of 3 with Me 3 SiOTf affords, after some time in the thermodynamically favoured 1,1 addition product over Si (21). The formation of 21 is assumed to proceed via the unstable 1,4-adduct 22 which undergoes isomerisation to the thermodynamic product over a period of some days.…”

S–H Bond Activation in Hydrogen Sulfide by NHC-Stabilized Silyliumylidene Ions

“…For comparison, the neutral silylene derivative of silyliumylidene II (Figure 1) has been applied in the activation of several small molecules such as NH3, H2S, H2O, AsH3 and PH3 [50][51][52]. A theoretical assessment of the observed divergent reactivity was provided by Szilvási and coworkers, revealing a unique insertion step to form the 1,4 adducts, followed by varying pathways towards the products [53].…”