Synthesis, characterization and reactivity of (SIDipp)AsK – A NHC‐arsinidenyl compound

Abstract

Herein, the characterization and reactivity of the metalated arsinidenyl (SIDipp)AsK (1 a) is described. This compound was obtained via deprotonation of the saturated “parent arsinidene” (SIDipp)AsH (1) with the strong base benzyl potassium and appears as pyrophoric, insoluble, red solid. The ability of crown ethers to improve the solubility of metal compounds through complex formation has been used to obtain crystals of (SIDipp)AsK. Thus, the crown ether complex [K(18‐crown‐6)(SIDipp)As] (1 b) was characterized as the first of its kind by single crystal x‐ray diffraction. Furthermore, (SIDipp)AsK was treated with di‐tert‐butylchloropnictogens (tBu2ECl, E=P, As, Sb, Bi) to give the interpnictogen compounds of the type (SIDipp)AsEtBu2 (2–5) with low valent arsenic substituents.

N‐Heterocyclic Carbene‐Arsinidenide Iridium Complexes

“…In contrast to the recent advances in NHC‐phosphinidene chemistry, the corresponding heavier arsinidene derivatives (NHC)AsR have only been scarcely studied, [14] and structurally characterized metal complexes of the type (NHC)AsML n are virtually unknown with the exception of a germanium species in which the (NHC)As moiety was constructed by template synthesis [15] . Very recently, however, von Hänisch presented the preparation of the potassium salt [(SIDipp)AsK], which was used for the preparation of the dipnictogen compounds [(SIDipp)AsE t Bu 2 ] (E=P, As, Sb, Bi) [16] . Moreover, a few gallium complexes containing terminal (CAAC)As ligands (CAAC=cyclic alkyl amino carbene) were reported by Schulz , [17] while the polarized acyclic arsaalkene Me 3 SiAs=C(NMe 2 ) 2 was used by Weber for the synthesis of the half‐sandwich complex [(η 5 ‐C 5 Me 5 )Fe(CO) 2 {AsC(NMe 2 ) 2 }] from [(η 5 ‐C 5 Me 5 )Fe(CO) 2 Br] [18] .…”

“…It proved difficult to observe the 13 C NMR signals of the NCN carbon atoms, however, this signals was observed at 185.7 ppm in case 4b , which is at slightly higher field compared to the chemical shifts reported for the species [(SIDipp)AsE t Bu 2 ] (E=P, As, Sb, Bi) at ca. 199 ppm [16] …”

“…[15] Very recently, however, von Hänisch presented the preparation of the potassium salt [(SIDipp)AsK], which was used for the preparation of the dipnictogen compounds [(SIDipp)-AsEtBu 2 ] (E = P, As, Sb, Bi). [16] Moreover, a few gallium complexes containing terminal (CAAC)As ligands (CAAC = cyclic alkyl amino carbene) were reported by Schulz, [17] while the polarized acyclic arsaalkene Me 3 SiAs=C(NMe 2 ) 2 was used by Weber for the synthesis of the half-sandwich complex [(η 5 -C 5 Me 5 )Fe-(CO) 2 {AsC(NMe 2 ) 2 }] from [(η 5 -C 5 Me 5 )Fe(CO) 2 Br]. [18] In analogy to this procedure, we envisaged that the NHC-trimethylsilyarsenidene adducts (IDipp)AsSiMe 3 (1 b) and (IMes)AsSiMe 3 (2 b), which were established through joint efforts of the Goicoechea, Scheer and Tamm groups, [19] could provide a convenient access to transition metal NHC-arsinidenide complexes of the type (NHC)AsML n by reaction with metal halides such as [(η 5 -C 5 Me 5 )IrCl 2 ] 2 .…”

“…199 ppm. [16] Single crystals of the arsenidenide complex 3 b • C 6 H 14 were grown from toluene/n-hexane solution at À 30 °C, and the molecular structure of 3 b was established by X-ray diffraction analysis (Figure 1). 3 b • C 6 H 14 crystallized in the monoclinic space group P2 1 /n and is isotypic with the phosphinidenide analog 3 a.…”