Binary Group 15 Polyazides. Structural Characterization of [Bi(N3)4]鈭?/sup>, [Bi(N3)5]2鈥?/sup>, [bipy路Bi(N3)5]2鈥?/sup>,

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• 作者：Ralf Haiges ; Martin Rahm ; David A. Dixon ; Edward B. Garner ; III ; Karl O. Christe
• 刊名：Inorganic Chemistry
• 出版年：2012
• 出版时间：January 16, 2012
• 年：2012
• 卷：51
• 期：2
• 页码：1127-1141
• 全文大小：697K
• 年卷期：v.51,no.2(January 16, 2012)
• ISSN：1520-510X

文摘

The binary group 15 polyazides As(N₃)₃, Sb(N₃)₃, and Bi(N₃)₃ were stabilized by either anion or donor鈭抋cceptor adduct formation. Crystal structures are reported for [Bi(N₃)₄]^{鈥?/sup>, [Bi(N₃)₅]2鈥?/sup>, [bipy路Bi(N₃)₅]2鈥?/sup>, [Bi(N₃)₆]3鈥?/sup>, bipy路As(N₃)₃, bipy路Sb(N₃)₃, and [(bipy)₂路Bi(N₃)₃]₂. The lone valence electron pair on the central atom of these pnictogen(+III) compounds can be either sterically active or inactive. The [Bi(N₃)₅]2鈥?/sup> anion possesses a sterically active lone pair and a monomeric pseudo-octahedral structure with a coordination number of 6, whereas its 2,2鈥?bipyridine adduct exhibits a pseudo-monocapped trigonal prismatic structure with CN 7 and a sterically inactive lone pair. Because of the high oxidizing power of Bi(+V), reactions aimed at Bi(N₃)₅ and [Bi(N₃)₆]鈥?/sup> resulted in the reduction to bismuth(+III) compounds by [N₃]鈥?/sup>. The powder X-ray diffraction pattern of Bi(N₃)₃ was recorded at 298 K and is distinct from that calculated for Sb(N₃)₃ from its single-crystal data at 223 K. The [(bipy)₂路Bi(N₃)₃]₂ adduct is dimeric and derived from two BiN₈ square antiprisms sharing an edge consisting of two 渭1,1-bridging N₃ ligands and with bismuth having CN 8 and a sterically inactive lone pair. The novel bipy路As(N₃)₃ and bipy路Sb(N₃)₃ adducts are monomeric and isostructural and contain a sterically active lone pair on their central atom and a CN of 6. A systematic quantum chemical analysis of the structures of these polyazides suggests that the M06-2X density functional is well suited for the prediction of the steric activity of lone pairs in main-group chemistry. Furthermore, it was found that the solid-state structures can strongly differ from those of the free gas-phase species or those in solutions and that lone pairs that are sterically inactive in a chemical surrounding can become activated in the free isolated species.}