Facile Access to NaOC≡As and Its Use as an Arsenic Source To Form Germylidenylarsinidene Complexes

Abstract

A facile, one-pot synthesis of [Na(OC≡As)(dioxane) ] (x=2.3-3.3) in 78 % yield is reported through the reaction of arsine gas with dimethylcarbonate in the presence of NaO Bu and 1,4-dioxane. It has been employed for the synthesis of the first arsaketenyl-functionalized germylene [LGeAsCO] (2, L=CH[CMeN(Dipp)] ; Dipp=2,6- Pr C H ) from the reaction with LGeCl (1). Upon exposure to ambient light, 2 undergoes CO elimination to form the 1,3-digerma-2,4-diarsacyclobutadiene [L Ge As ] (3), which contains a symmetric Ge As ring with ylide-like Ge=As bonds. Remarkably, the CO ligand located at the arsenic center of 2 can be exchanged with PPh or an N-heterocyclic carbene NHC donor ( NHC=1,3-diisopropyl-4,5-dimethylimidazol-2-ylidene) to afford the novel germylidenylarsinidene complexes [LGe-AsPPh ] (4) and [LGe-As( NHC)] (5), respectively, demonstrating transition-metal-like ligand substitution at the arsinidene-like As atom. The formation of 2-5 and their electronic structures have been studied by DFT calculations.

Synthesis and Reactivity of Nickel‐Stabilised μ2:η2,η2‐P2, As2 and PAs Units

“…Diarsacyclobutadiene-type compounds analogous to A have also recently been reported using AsCO À as ar eagent. [15] Thef urther reactivity of the E 2 Pn 2 cores of the resulting molecules remains largely unexplored despite the fact that, particularly in the diphosphene bridged compounds,they may be of relevance for the synthesis of novel pnictogen-containing molecules.A lso,g iven that such species are formed through dimerisations,i ti sa lso possible to envision the synthesis of compounds with ap hosphaarsene (PAs) core through the dimerization of ap hosphinidene with an arsinidene.H erein, we describe our attempts to explore such possibilities.W ei nvestigate the reactivity of two nickel(I) compounds,C pNi(NHC) (where Cp = cyclopentadienyl; NHC = 1,3-bis(2,4,6-trimethylphenyl)-imidazol-2-ylidene Figure 1. Selected examples of dimeric compounds resulting from the decarbonylation of phosphaketenyl precursors.…”

From As‐Zincoarsasilene (LZn‐As=SiL′) to Arsaethynolato (As≡C−O) and Arsaketenylido (O=C=As) Zinc Complexes

“…The molecular structure of 5 (Figure ) shows the presence of the [As≡CO] − anion that coordinates through oxygen to the silicon atom of the [LZnOSi(L′)] + fragment, with a C‐O‐Si angle of 124.0(1)°, and Si−O OCAs distance of 1.744(1) Å, longer than the Si−O distance of the SiOZn bridge ( d (Si1−O1)=1.574(1) Å), and indeed the vast majority of reported Si−O bonds, suggesting a relatively weak O AsCO −Si bonding interaction. The As≡CO unit in 5 exhibits an almost linear As‐C‐O arrangement of 178.5(2)°, and expected short As−C ( d (As1−C56)=1.678(2) Å) and elongated C−O ( d (C56−O2)=1.271(2) Å) distances, when compared with known As ‐metalloarsaketenylido complexes ( d (As−C)=(1.72–1.75) Å, d (C−O)=(1.17–1.18) Å) . The As≡C distance in 5 is confirmed by DFT calculations (1.66 Å), and the C−O distance is intermediate between a C−O single (1.38 Å) and double bond (1.24 Å) .…”

Intercepting a Transient Phosphino‐Arsinidene

“…[13] Driess andc o-workersp ostulated that a germylenyl-arsinidenew as generated as at ransient species in the formation of aG e 2 As 2 heterocycle whichc ould be trapped with Lewis bases prior to dimerisation. [14] So far,t he preparation of af ree arsinidene has eluded the skills of chemists. However,p hosphino-nitrene D, [15,16] and phosphino-phosphinidene E, [17,18] have recently been isolated and their reactivity has been investigated.…”

“…However,p hosphino-nitrene D, [15,16] and phosphino-phosphinidene E, [17,18] have recently been isolated and their reactivity has been investigated. Thel atter was prepared by photolytic eliminationo fc arbon monoxide from the corresponding phosphanyl-phosphaketene.W ith AsCO À as ap otentially suitable source of arsaketenes and As À now being available on ap reparatively usefuls cale, [12,14,19] we attempted the synthesis of the phosphino-arsinidene F employing the bulky diazaphospholidine backbone utilised in the isolationofE.…”