Synthesis and Characterization of Free and Coordinated 1,2,3-Tripnictolide Anions

Abstract

We have investigated the chemical reactivity of heptaatomic anionic clusters of the group 15 elements ([E7]3–/[HE7]2–, E = P, As) toward the symmetric and asymmetrically substituted alkynes diphenylacetylene and phenylacetylene. The results reported herein, alongside a previous report on the reactivity of such clusters toward acetylene, describe a versatile route by which to access otherwise elusive 1,2,3-tripnictolide anions of the general formula [E3C2RR′]− (R = R′ = H, E = P (1), As (2); R = R′ = C6H5, E = P (3) As (4); R = H, R′ = C6H5, E = P (5), As (6)). These species can be isolated as [K(18-crown-6)]+ or [K(2,2,2-crypt)]+ salts. All anions were characterized by multielement NMR spectroscopy and electrospray mass spectrometry. In addition, single-crystal X-ray diffraction structures of the novel species [K(18-crown-6)(THF)2][3], [K(2,2,2-crypt)][4]·xTHF (x = 0, 0.5), and [K(18-crown-6)THF][6] were also obtained. The chemical reactivity of these group 15 cyclopentadienyl analogues has been explored in a series of ligand displacement reactions with Mo(CO)3(L)3 (L = CO, CH3CN) to yield the complex anions [(η5-E3C2H2)Mo(CO)3]− (E = P (7), As (8)), [{η5-E3C2(C6H5)2}Mo(CO)3]− (E = P (9), As (10)), and [{η5-E3C2H(C6H5)}Mo(CO)3]− (E = P (11), As (12)).

Hydropnictination Reactions of Carbodiimides and Isocyanates with Protonated Heptaphosphide and Heptaarsenide Zintl Ions

“…[25,26] During the course of these studies we have reported that the hydrogenheptaphosphide dianion [HP 7 ] 2-(1) reacts with carbodiimides to yield exo-functionalized cages with amidine functionalities [-C(NR)(NHR); R = Dipp, iPr, Cy]. [25,26] During the course of these studies we have reported that the hydrogenheptaphosphide dianion [HP 7 ] 2-(1) reacts with carbodiimides to yield exo-functionalized cages with amidine functionalities [-C(NR)(NHR); R = Dipp, iPr, Cy].…”

Reactions of Polyarsenides with Acetylene: Synthesis and Characterization of [Cs([18]crown‐6)]2As7C14H11·6NH3 and As2C6H6

“…To our best knowledge, As 7 C 14 H 11 2-is the first mono-substituted organo-heptaarsenide anion with an unsaturated hydrocarbon-only substituent. In addition [K(2,2,2-crypt)][(PhCH 2 ) 2 As 7 ] is known as another example of a hydrocarbon-substituted heptaarsenide cage. [4] Substitution with carbodiimides and isocyanates was shown by Turbervill and Goicoechea previously.…”

“…[1][2][3] These 1,2,3-tripnictolide anions are of special interest in the field of organometallic chemistry as their improved π acceptor capability compared to the cyclopentadienyl anion C 5 H 5 -offers the possibility to stabilize electron rich transition metal complexes. Examples of complex compounds containing [E 3 C 2 RRЈ] -were given by Goicoechea et al, namely [(η 5 -E 3 C 2 RRЈ)Mo(CO) 3 ] -(E = P/As; R = RЈ = H/Ph; R = H, RЈ = Ph).…”

“…Examples of complex compounds containing [E 3 C 2 RRЈ] -were given by Goicoechea et al, namely [(η 5 -E 3 C 2 RRЈ)Mo(CO) 3 ] -(E = P/As; R = RЈ = H/Ph; R = H, RЈ = Ph). [2] As the synthetic procedure for the formation of 1,2,3-tripnictolides is mainly based on thermodynamically controlled conditions and furthermore, no investigations were carried out until now to clarify the mechanistic route of the 1,2,3-tripnictolid formation, we performed experiments regarding the reactivity of group 15 Zintl ions towards acetylene and diphenyl acetylene in liquid ammonia under more kinetically controlled conditions. ylethenyl-heptaarsenide di-anion can be seen as the first step towards the formation of 1,2,3-triarsolides.…”

Expanding the horizons of sky blue nitrosocarboranes

“…These achievements opened up the way to the use of metallocenes in applied and material science from polymerization catalysis to UV fluorescent materials [2]. Nowadays several metallocenes are known in which not just the central iron atom is replaced by other transition metals but also the ligands are changed to heterocyclopentadienyl analogues containing other main group elements such as P, As or Sb [4,5]. Notwithstanding, the number of known metallocenes possessing silicon or germanium containing heterocycles is small.…”