Pnictogen–Silicon Analogues of Benzene

Since
the discovery of the first “inorganic benzene”
(borazine, B3N3H6), the synthesis
of other noncarbon derivatives is an ongoing challenge in Inorganic
Chemistry. Here we report on the synthesis of the first pnictogen–silicon
congeners of benzene, the triarsa- and the triphospha-trisilabenzene
[(PhC­(NtBu)2)3Si3E3] (E = P (1a), As (1b)) by
a simple metathesis reaction. These compounds are formed by the reaction
of [Cp″2Zr­(η1:1-E4)]
(E = P, As; Cp″ = C5H3tBu2) with [PhC­(NtBu)2SiCl]
in toluene at room temperature along with the silicon pnictogen congeners
of the cyclobutadiene, [(PhC­(NtBu)2)2Si2E2] (E = P (2a), As
(2b)), which is unprecedented for the arsenic system 2b. All compounds were comprehensively characterized, and
density functional theory calculations were performed to verify the
stability and the aromatic character of the triarsa- and the triphospha-trisilabenzene.

自首个"无机苯"（硼氮苯，B3N3H6）被发现以来，合成非碳无机衍生物始终是无机化学领域的长期研究挑战。本文报道了通过简单复分解反应合成首例苯的氮族元素（pnictogen）-硅同系物：三磷杂三硅苯与三砷杂三硅苯[(PhC(NtBu)₂)₃Si₃E₃]（E=P（1a）、As（1b））。该类化合物由[Cp″₂Zr(η¹:¹-E₄)]（E=P、As；Cp″=二叔丁基环戊二烯基，C5H3tBu2）与[PhC(NtBu)₂SiCl]在甲苯中室温条件下反应生成，同时伴随环丁二烯的氮族元素-硅同系物[(PhC(NtBu)₂)₂Si₂E₂]（E=P（2a）、As（2b））生成；其中砷体系的2b产物此前尚无文献报道。所有化合物均得到了全面表征，并通过密度泛函理论（density functional theory, DFT）计算验证了三磷杂三硅苯与三砷杂三硅苯的稳定性与芳香性。