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The binary group 15 polyazides As(N(3))(3), Sb(N(3))(3), and Bi(N(3))(3) were stabilized by either anion or donor-acceptor adduct formation. Crystal structures are reported for [Bi(N(3))(4)](-), [Bi(N(3))(5)](2-), [bipy·Bi(N(3))(5)](2-), [Bi(N(3))(6)](3-), bipy·As(N(3))(3), bipy·Sb(N(3))(3), and [(bipy)(2)·Bi(N(3))(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(N(3))(5)](2-) anion possesses a sterically active lone pair and a monomeric pseudo-octahedral structure with a coordination number of 6, whereas its 2,2'-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(N(3))(5) and [Bi(N(3))(6)](-) resulted in the reduction to bismuth(+III) compounds by [N(3)](-). The powder X-ray diffraction pattern of Bi(N(3))(3) was recorded at 298 K and is distinct from that calculated for Sb(N(3))(3) from its single-crystal data at 223 K. The [(bipy)(2)·Bi(N(3))(3)](2) adduct is dimeric and derived from two BiN(8) square antiprisms sharing an edge consisting of two μ(1,1)-bridging N(3) ligands and with bismuth having CN 8 and a sterically inactive lone pair. The novel bipy·As(N(3))(3) and bipy·Sb(N(3))(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. 相似文献
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用密度泛函理论(DFT)研究了As-5、[As5M]-和[As5MAs5]2- (M=Ti, Zr, Hf)的结构、频率、能量以及芳香性, 详细讨论了体系中不同类型的键和电子如化学键、孤对电子、核电子等对总的核独立化学位移(NICS)的影响. 结果表明, As-5、[As5M]-和[As5MAs5]2-的基态结构分别具有D5h、C5v和D5h对称性, 而且都具有芳香性. As-5 (D5h)的芳香性主要来源于As—As π键和As—As σ键的作用. [As5M]-(C5v)中各种As—M键的NICS分割值占主要优势, 其次是As—As之间形成的σ键. [As5TiAs5]2-(D5h)中, As—As π键的作用占主要优势. [As5ZrAs5]2-(D5h)中, As—As π键对体系总的NICS贡献相对减小, 而As—Zr键的作用增强. [As5HfAs5]2-(D5h)的芳香性主要来自As—Hf键的作用. 相似文献
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V. V. Sharutin I. V. Egorova O. K. Sharutina E. A. Boyarkina 《Russian Journal of Coordination Chemistry》2008,34(6):461-465
The complexes [Ph3PMe] 2 + [BiI5]2? (I) and [Ph3PMe] 2 + [BiI5 · C 5H5N]2? · C 5H5N (II) were synthesized by the reaction of bismuth triiodide with triphenylmethylphosphonium iodide, and their structures were determined by X-ray diffraction analysis. The P atom in cation I has slightly distorted tetragonal coordination polyhedron (the CPC angles 109.42(4)° and 109.52(4)°, the bond lengths P-CPh 1.779(2), P-CMe 1.793(1) Å. The Bi atom in the anion of complex I has an ideal trigonal-bipyramidal coordination polyhedron (Bi-Ieq 3.0031(4), Bi-Ieq 3.0485(5) Å). The crystal of complex II consists of the anions [BiI5 · C 5H5N]2?, solvated pyridine molecules, and two types of crystallographically independent tetrahedral triphenylmethylphosphonium cations (the angles CPC 106.9(1)°–111.7(1)°, the distances P-CPh 1.785(3)–1.792(3), P-CMe 1.793(3), 1.786(3) Å). The Bi atoms in the anion of complex II have a distorted octahedral coordination polyhedron (Bi-I 3.0878(4)–3.1240(3), Bi-N(1) 2.628(3) Å). 相似文献
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By reaction of elemental bismuth, sulfur, bismuth(III) chloride and gallium(III) chloride in the ionic liquid (BMIm)Cl (BMIm: 1-butyl-3-methylimidazolium), [Bi(3)GaS(5)](2)[Ga(3)Cl(10)](2)[GaCl(4)](2)·S(8) is obtained as red transparent crystals. According to X-ray structure analysis based on single crystals, the title compound crystallizes with triclinic lattice symmetry and is composed of heterocubane-type [Bi(3)GaS(5)](2+) cations, trimeric star-shaped [Ga(3)Cl(10)](-) anions with three (GaCl(4)) tetrahedra sharing a single central chlorine atom, monomeric [GaCl(4)](-) tetrahedra and neutral, crown-shaped S(8)-rings. Here, the heterocubane [Bi(3)GaS(5)](2+) as well as the star-shaped [Ga(3)Cl(10)](-) are observed as building units for the first time. [Bi(3)GaS(5)](2)[Ga(3)Cl(10)](2)[GaCl(4)](2)·S(8) is further characterized by X-ray powder diffraction as well as by thermogravimetry/differential thermal analysis. 相似文献
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天然檀香是人们喜爱的一种高级香料。其香气甜润而富有传统的东方香型特色。由于天然檀香的产量少,价格昂贵,而且提炼天然檀香的檀香木来源日益减 相似文献
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1 INTRODUCTION Triazole nuclei appear frequently in the structures of various natural products and biologically active compounds, notably thiamine (vitamin B), peni- cillins, antibiotics such as micrococcin[1], and many metabolic products of fungi and p… 相似文献
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《Tetrahedron letters》1987,28(14):1511-1514
The title compounds are prepared by reaction of 1.3-oxazolo[13.2-α]pyridinium- and 1.3.4-oxadiazolo[3.2-α]pyridiniumsalts with P(SiMe3)3, resp. As(SiMe3)3. 相似文献
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Single crystals of a new compound containing triphenylguanidinium and bis(dicarbollide)nickel(III) [C(NHC6H5)3][Ni(B9C2H11)2] are obtained and analyzed by LOW-TEMPERATURE. Crystallographic data are: C23H40B18N3Ni, M = 611.87, monoclinic system, space group P21/c, unit cell parameters: a = 21.9085(5) Å, b = 19.9294(4) Å, c = 14.8721(4) Å, β = 91.4033(9)°, V = 6491,5(4) Å3, Z = 8, d x = 1.252 g/cm3, T = 100 K, F(000) = 2536, μ = 0.621 mm?1. The structure was solved by direct and Fourier methods and refined by the full matrix least squares technique in the anisotropic/isotropic (for H atoms) approximation up to the final factor R 1 = 0.053 for 10429 I hkl ≥ 2σ I (Bruker X8 APEX diffractometer, {ie547-1} radiation). It contains two independent [C(NHC6H5)3]+ cations with different conformations and two [Ni(B9C2H11)2]? anions with the same transoid conformation. Three types of weak intermolecular interactions are found: {ie547-2}; C-H…π between the H(C) atoms of cluster anions and delocalized π systems of Ph rings of cations; π…π interactions of Ph rings of cation 2 with each other. 相似文献
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The development of new catalyst-free green and efficient protocol to access 5′-thioxospiro[indoline-3,3′-[1,2,4]triazolidin]-2-ones/spiro[indoline-3,3′-[1,2,4]triazolidine]-2,5′-diones, potential privileged scaffolds for drug discovery, is disclosed. Key feature of this methodology is the dual use of glycerol—a recyclable, bioorganic compound, as a solvent cum promoter. Other highlights include use of inexpensive reagents, mild reaction conditions, operational simplicity, short reaction time, no need for chromatographic purification, and high yields. 相似文献
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报道了以2-甲(乙)基苯胺1a,1b为原料经Sandmeyer反应得到7-甲(乙)基靛红2a,2b;再以环境友好的聚乙二醇-400为溶剂,N-溴代丁二酰亚胺(NBS)为绿色溴代试剂对2a,2b进行5位溴代,得到5-溴-7-甲(乙)基靛红3a,3b;2a,2b,3a,3b进一步氮烃基化得到1-烃基-7-甲(乙)基靛红4a~4j和1-烃基-5-溴-7-甲(乙)基靛红5a~5j.2a,2b,3a,3b,4a~4j,5a~5j分别与硫代氨基脲,在以二氧六环为溶剂,碳酸钾存在的条件下回流反应,简便地合成了24种5H-[1,2,4]三嗪并[5,6-b]吲哚-3-硫醇类杂环化合物6a~6x.大部分化合物未见文献报道,其结构经红外光谱、质谱、核磁氢谱(碳谱)和元素分析确认. 相似文献
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The hydrothermal reaction of MoO3, V, Na2WO4· 2H2O, [N(CH2CH2)3N](1,4-diazabicyclo[2.2.2] octane), and H2O at 160°C for 90h gave dark-brown crystals of [HN(CH2CH2)3N]2[HMoVMoVI
5O19]·[N(CH2CH2)3N], (1), in 40% yield. Complex (1) is the first one-electron reduced mixed-valence hexamolybdate to be crystallized and structurally characterized. The crystal structure of (1) consists of discrete [HMoVMoVI
5O19]2– anions, [HN-(CH2CH2)3N]+ cations, and neutral [N(CH2CH2)3N] molecules of crystallization. 相似文献
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《Journal of organometallic chemistry》1992,423(1):C20-C23
Complexes [CpRuSR]2 and [Cp RuSR]2, where Cp = η5-C5Me5, Cp = η5-C5Me4Et, R Et, tBu, (tBuO)3Si, are synthesized by exchange of the metboxo groups in [CpRuOMe]2 with the respective thiols. An X-ray molecular structure determination of [Cp RuSEt]2 confirms the dimeric structure with co-ordinatively unsaturated 16 VE Ru. The molecular geometry of the thiol-bridged dimer is compared to that of the oxo analogue. 相似文献
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《Journal of organometallic chemistry》1987,319(1):77-85
Treatment of [Cp(CO)3Mo]− with ClCOCF2COCl gave [Cp(CO)3MoCOCF2COMo(CO)3Cp] (1), which, by loss of CO gave [Cp(CO)3MoCOCF2Mo(CO)3Cp] (2). Further loss of CO moieties from 2 resulted in a mixture of different molybdenum complexes. The trinuclear complex [Cp3(CO)6Mo3(μ3-CF)] (3) was considered the most interesting one. The crystal structure of 3 is presented. The compound appears as two crystallographical independent molecules of identical structure, which crystallize in two enantiomeric forms. 相似文献