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Ca6GaN5 and Ca6FeN5: Compounds Containing [CO3]2?-isosteric Anions [GaN3]6? and [FeN3]6? The isotypic phases Ca6GaN5 and Ca6FeN5 (hexagonal, P63/mem; a = 627.7(3)/ 623,7(1) pm, c = 1219.8(3)/1233.2(6) pm; Z = 2) are prepared by reaction of Ca/Ga mixtures (molar ratio 6:1) and Fe/Ca3N2/Ca mixtures (molar ratios from 3:1:13 to 5:2:15) with nitrogen at temperatures of 850°C and 950°C to 1100°C, respectively. The structures contain trigonal-planar anions [MN3]6? which are isosteric to carbonate ions (Ga? N: 195,1(28) pm; Fe? N: 177,0(15) pm). The structures are closely related to those compounds of the hydrotalcite group.  相似文献   

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A one step synthesis of [TcO3]+[SO3F]? is reported. The compound is volatile at room temperature and has according to calculations a tetrahedral coordination around Tc and a monodentate SO3F group. In the solid state the [SO3F]? anion bridges three [TcO3]+ cations, and vice versa. Space group P21/c, Z = 4, lattice dimensions at 173 K: a = 695.4(11), b = 808.6(12), c = 893.3(14) pm, β = 97.36(8)°.  相似文献   

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Pseudochalkogen Compounds. XVI. Infrared-spectroscopic Investigations of Cyanamidomonophosphates, [PO4?n(NCN)n]3? Infrared spectroscopic investigations of trisodium cyanamidomonophosphates of the general type Na3[PO4?n(NCN)n] · aq (n: 1, 2, 3) are reported. The vibrational spectra of the compounds are confirming very clearly the special position of cyanamidophosphates within the group of substituted phosphates: Cyanamidophosphates are characterized by a full participation of pseudochalkogen groups representing NCN substituents into the mesomeric system of the anions and an only slight shortening of the P? O distances in comparision to [PO4]3?. Characteristic frequencies between 970 and 1150 cm?1 are attributed to v(PO4?nNn)-stretching frequencies. A partial 15N labelling of the monocyanamidophosphate anion, [PO3NCN]3? leads to some splitting or shifting of frequencies being connected with vibrations of the NCN group; isolated v(P? N) stretching frequencies cannot be found.  相似文献   

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Until now, polycyclic bismuth polyanions have not been known—thus discriminating bismuth from its lighter congeners. However, the synthesis of [K([2.2.2]crypt)]3(Bi11)?2 py?tol, allows us to present the first structurally characterized homoatomic, polycyclic bismuth polyanion, which exhibits the [P11]3? “ufosan” structure. It was obtained upon treatment of [K([2.2.2]crypt)]2(GaBi3)?en with the solvent pyridine. The binary Zintl anion [GaBi3]2? decomposes under oxidative coupling of pyridine molecules and release of H2 to form the title compound. The unprecedented reaction, its products and by‐products were investigated by means of spectroscopy, spectrometry, and DFT studies. All findings reveal the specific reaction conditions to be crucial for the formation of the [Bi11]3? ion—and indicate the possibility of the generation and isolation of further, large bismuth polyanions.  相似文献   

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Are the ‘Textbook Anions’ O2?, [CO3]2?, and [SO4]2? Fictitious? Experimental second electron affinities are still unknown for the title anions. It will be shown by means of quantum chemical ab initio calculations that these dianions are unstable with respect to spontaneous ionization. They all must be designated as non-existent.  相似文献   

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We report the characterization of the compound [K([2.2.2]crypt)]4[In8Sb13], which proves to contain a 1:1 mixture of [Sb@In8Sb12]3? and [Sb@In8Sb12]5?. The tri‐anion displays perfect Th symmetry, the first completely inorganic molecule to do so, and contains eight equivalent In3+ centers in a cube. The gas‐phase potential energy surface of the penta‐anion has eight equivalent minima where the extra pair of electrons is localized on one In+ center, and these minima are linked by low‐lying transition states where the electron pair is delocalized over two adjacent centers. The best fit to the electron density is obtained from a model where the structure of the 5? cluster lies close to the gas‐phase transition state.  相似文献   

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For decades the chemistry of polyhalides was dominated by polyiodides and more recently also by an increasing number of polybromides. However, apart from a few structures containing trichloride anions and a single report on an octachloride dianion, [Cl8]2?, polychlorine compounds such as polychloride anions are unknown. Herein, we report on the synthesis and investigation of large polychloride monoanions such as [Cl11]? found in [AsPh4][Cl11], [PPh4][Cl11], and [PNP][Cl11]?Cl2, and [Cl13]? obtained in [PNP][Cl13]. The polychloride dianion [Cl12]2? has been obtained in [NMe3Ph]2[Cl12]. The novel compounds have been thoroughly characterized by NMR spectroscopy, single‐crystal Raman spectroscopy, and single‐crystal X‐ray diffraction. The assignment of their spectra is supported by molecular and periodic solid‐state quantum‐chemical calculations.  相似文献   

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Preparation and vibrational spectra of the complexes [MBr6]?, [Br5MN3]? and [Br5MNPPh3]? of niobium and tantalum. Cyrstal structure of PPh4[NbBr6] The compounds PPh4[MBr6] and PPh4[MBr5N3] are obtained by reaction of MBr5 with PPh4Br or PPh4N3, respectively, in CH2Cl2 solution (M ? Nb, Ta). The azido complexes PPh4[MBr5N3] can also be obtained by reactions of the hexabromo complexes with iodine azide. According to its i.r. spectrum the symmetry of the [MBr6]? ion is lower than Oh in the solide state. This is corfirmed for PPh4[NbBr6] by a crystal structure analysis; it crystallizes in the monoclinic space group B2/b with four formula units in the unit cell and with the lattice constants a = 2301, b = 1777, c = 686 pm and γ = 96,6°. The structure was determined with X-ray diffraction data and was refined to a residual index of R = 0.055. The [NbBr6]? ion has the symmetry Ci, the deviations from Oh being small. In the azido complexes [MBr5N3]? the azido groups are covalently linked with the metal. From [NbBr5N3]? and PPh3 the complex [Br5Nb?N?PPh3]?, is obtained; for the analogous formation of the corresponding Ta complex photochemical activation is necessary. In this way the complex [Cl5Nb?N?AsPh3]? can also be obtained. I.r. spectra of all the compounds are reported and assigned.  相似文献   

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