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81.
H. Binder S. Sylemez R. Stckle A. Pfitzner M. Hofmann P. v. R. Schleyer 《无机化学与普通化学杂志》1997,623(7):1157-1162
Thia- and Selena-arachno-undecaborane 6,7-μ-(CH3E)B10H13. Crystal Structure of arachno-6,7-μ-(CH3Se)B10H13. Theoretical Investigations of the Molecular Structures and 11B NMR Shifts of arachno-6,7-μ-(CH3E)B10H13 The reaction of B10H14 with (CH3)2S yields with loss of H2 the base adduct 6,9-[(CH3)2S]2B10H12. Although an analogous reaction between B10H14 with disulfanes or diselenanes was expected to produce 6,9 bridged dichalcogen derivatives, (CH3)2S2 failed to react even under reflux conditions. Trisulfane (CH3)2S3 does react, but the pathway is different and leads to (CH3S)B10H13 2 without loss of H2. Unlike of (CH3)2S2, (CH3)2Se2 yields (CH3Se)B10H13, 3 . Both 2 and 3 are formed by substitution of a bridging hydrogen and could be obtained in pure form and characterized 11B NMR spectroscopically. A single crystal X-ray structure analysis also was performed on 3 (space group P21/c). The molecular structures of 2 and 3 were optimized at the MP2 level and 11B NMR shifts were computed at the IGLO-SCF, GIAO-SCF and GIAO-B3LYP levels of theory. 相似文献
82.
Synthesis of the Silatetraphospholanes (tBuP)4SiMe2, (tBuP)4SiCl2, and (tBuP)4Si(Cl)SiCl3 Molecular and Crystal Structure of (tBuP)4SiCl2 The reaction of the diphosphide K2[(tBuP)4] 7 with the halogenosilanes Me2SiCl2, SiCl4 or Si2Cl6 in a molar ratio of 1:1 leads via a [4 + 1]-cyclocondensation reaction to the silatetraphospholanes (tBuP)4SiMe2 1,1-dimethyl-1-sila-2,3,4,5-tetra-t-butyl-2,3,4,5-tetraphospholane, 1 , (tBuP)4SiCl2, 1,1-dichloro-1-sila-2,3,4,5-tetra-t-butyl-2,3,4,5-tetraphospholane, 2 , and (tBuP)4Si(Cl)SiCl3, 1-chloro-1-trichlorsilyl-1-sila-2,3,4,5-tetra-t-butyl-2,3,4,5-tetraphospholane, 3 , respectively, with the 5-membered P4Si ring system. The reaction leading to 1 is accompanied with the formation of the by-product Me2(Cl)-Si–(tBuP)4–Si(Cl)Me2 1a (5:1), which has a chain structure. On warming to 100°C 1a decomposes to 1 and Me2SiCl2. The compounds 2 and 3 do not react further with an excess of 7 due to strong steric shielding of the ring Si atoms by the t-butyl groups. 1, 2 and 3 could be obtained in a pure form and characterized NMR spectroscopically; 2 was also characterized by a single crystal structure analysis. 1a was identified by NMR spectroscopy only. 相似文献
83.
CuClS0.94Te1.06 and CuBrS0.92Te1.08, Two New Copper(I) Chalcogen Halides Containing Neutral [STe] Screws CuClS0.94Te1.06 and CuBrS0.92Te1.08 are two new, isotypic compounds of general composition CuXYY′ (X = halide, Y, Y′ = chalcogen) with a mixed chalcogen substructure. They crystallize in the monoclinic system, space group P21/n (No. 14), a = 7.878(2), b = 4.727(1), c = 10.759(2) Å, β = 103.97(2)°, V = 388.8(2) Å3 (CuClS0.94Te1.06) and a = 8.043(3), b = 4.746(2), c = 11.240(4) Å, β = 103.46(3)°, V = 417.3(3) Å3 (CuBrS0.92Te1.08), both with Z = 4. The crystal structures are dominated by ordered [STe±0]-screws. From a crystal chemical point of view the sulfur and tellurium atoms are significantly different. The melting points are 341 °C (CuClS0.94Te1.06) and 336 °C (CuBrS0.92Te1.08). The compounds CuXYY′ (X = Cl, Br, I; Y, Y′ = S, Se, Te) are compared and discussed. 相似文献
84.
Arno Pfitzner 《无机化学与普通化学杂志》1995,621(4):685-688
The Crystal Structure of Cu3SbSe3 The hitherto unknown crystal structure of Cu3SbSe3 has been determined from single crystals. The compound crystallizes in the orthorhombic system, space group Pnma (No. 62), with a = 7.9865(8), b = 10.6138(9) and c = 6.8372(7) Å, V = 579.6(1) Å3, Z = 4. Most remarkable feature of the structure are groups of three cis-edge-sharing tetrahedra [Cu3Se8] which are interlinked to a threedimensional arrangement by SbSe3-units. In contrast to Cu3SbS3 in the temperature range from ?180 to 25°C no hints for a phase transition could be detected by means of X-ray- and thermoanalytical methods. 相似文献
85.
Arno Pfitzner Manfred Zabel Franz Rau 《Monatshefte für Chemie / Chemical Monthly》2005,77(1):1977-1983
Black single crystals of MnBiS2Br were obtained by the reaction of stoichiometric amounts of α-MnS, Bi, S, and BiBr3 (3:2:3:1) at 600°C for 4 weeks. The compound crystallises in the monoclinic system, space group C2/m, with a = 12.767(2), b = 3.9468(4), c = 9.574(1) ?, β = 90.87(2)°, and Z = 4. The crystal structure refinement based on 720 reflections converged at R = 0.0244 and wR2 = 0.0579, respectively. MnBiS2Br forms a layer structure consisting of MnS6 octahedra, MnS2Br4 octahedra, and BiS3+2 pyramids. 相似文献
86.
Synthesis and Structure Analysis of (i-Pr)2NB(t-BuP)3 and (i-Pr)2NB(t-BuP)4 The diphosphide K(t-Bu)P-(t-BuP)2-P(t-Bu)K obtained by the cleavage reaction of the 3-membered ring system (i-Pr)2BN(t-BuP)2 with potassium reacts with t-BuPCl2 at ?78°C under ring expansion to form the P3B ring system (i-Pr)2NB(t-BuP)3 – 1,2,3-tri-t-butyl-tri-phospha-4-diisopropyl-aminoboretane ( 1 ). – The 5-membered P4B ring system (i-Pr)2NB(t-BuP)4 – 1,2,3,4-tetra-t-butyl-tetraphospha-5-diisopropylaminoborolidine, ( 2 ) – is formed from K(t-Bu)P? (t-BuP)2? P(t-Bu)K and (i-Pr)2NBCl2 analogous to the above reaction. 1 and 2 could be obtained in a pure form and characterized NMR spectroscopically and by X-ray structure analysis. 1 shows at 200 K two conformation isomers; for 2 31P-10,11B-isotopic shifts could be identified. 相似文献
87.
(HgBr2)3(As4S4)2 is obtained by high temperature reaction of stoichiometric amounts of HgBr2 and As4S4. It crystallizes in the monoclinic space group P21/c with the lattice constants a = 9.593(5) Å, b = 11.395(5) Å, c = 13.402(5) Å, β = 107.27(3)°, V = 1399(1) Å3, and Z = 2. The crystal structure consists of molecular units built from two undistorted As4S4 cages which are coordinated weakly by three almost linear HgBr2 units. Raman spectra clearly indicate minor bonding interactions between HgBr2 and As4S4. 相似文献
88.
Matthias Westerhausen Tobias Bollwein Peter Mayer Holger Piotrowski Arno Pfitzner 《无机化学与普通化学杂志》2002,628(6):1425-1432
Metalation and C‐C Coupling Reaction of 2‐Pyridylmethylamine: Synthesis and Structures of Methylzinc‐2‐pyridylmethylamide, Tris(trimethylsilyl)methylzinc‐2‐pyridylmethylamide and (Z)‐1‐Amino‐1,2‐bis(2‐pyridyl)ethene The metalation of 2‐pyridylmethylamine with dimethylzinc yields methylzinc‐2‐pyridylmethylamide ( 1 ), which shows a dimer‐trimer equilibrium in solution. Compound 1 crystallizes trimeric with a Zn3N3‐cycle in boat conformation. The endocyclic Zn‐N distances vary between 202 and 206 pm. Heating of this compound in toluene in the presence of dimethylzinc leads to the precipitation of zinc metal and to the formation of a few crystals of bis—[methylzinc‐2‐pyridylmethylamido]‐N, N′‐bis(methylzinc)‐2,3,5,6—tetrakis(2‐pyridyl)‐1,4‐diazacyclohexane ( 2 ). The protolysis of this solution with acetamide gives yellowish (Z)‐1‐amino‐1,2‐dipyridylethene ( 3 ) in a rather poor yield. The enamine tautomer is stabilized by N‐H···N hydrogen bridges. The demanding tris(trimethylsilyl)methyl group at the zinc atom allows the isolation of the dimeric tris(trimethylsilyl)methylzinc‐2‐pyridylmethylamide (4) 2 in good yield. A C‐C coupling reaction of this compound with dimethylzinc is not possible. 相似文献
89.
Pure yellow (CuI)P4Se4 was prepared by reaction of stoichiometric amounts of CuI, red P, and gray Se in evacuated silica ampoules. The crystal structure was determined from single crystals at room temperature. (CuI)P4Se4 crystallizes in the orthorhombic system, space group Cmca with a = 14.770 (1) Å, b = 12.029 (1) Å, c = 12.449 (1) Å, V = 2211.9(6) Å3, and Z = 8. The structure refinement converged to R = 0.0190 (wR = 0.0272) for 1020 independent reflections and 51 parameters. A prominent feature of the crystal structure are neutral polymeric P4Se4 strands which are connected by copper iodide. These strands consist of norbornane analogous P4Se3 cages which are linked by selenium bridges. The polymers are achiral since a mirror plane exists perpendicular to the strands. The single polymers are connected by [Cu2I2] units to form layers. These layers are stacked along the b axis and are connected by van der Waals-interactions only. Raman spectra of (CuI)P4Se4 differ significantly from Raman spectra of (CuI)3P4Se4 and catena-(P4Se4)x. 相似文献
90.
Susanne M. Tiefenthaler Marc Schlosser Florian Pielnhofer Ilya G. Shenderovich Arno Pfitzner Stefanie Gärtner 《无机化学与普通化学杂志》2020,646(3):82-87
In-depth investigations of the long-time known Zintl phase NaTl revealed a phase transition of tetragonal NaTl-tI8 [I41/amd; a = 5.2268(9) Å, c = 7.539(1) Å, V = 205.97(9) Å3] to Zintl's cubic NaTl-cF16 [Fd3 m; a = 7.4697(6) Å, V = 416.79(5) Å3] between 351 and 355 K. This phase transformation was observed for NaTl prepared by two different synthetic routes including Zintl's original procedure. An excess of sodium applied during the synthesis in liquid ammonia also resulted in the formation of NaTl-tI8. DSC measurements suggest a first order phase transition. In addition to in-situ temperature dependent powder X-ray diffraction experiments, DSC measurements and solid-state NMR investigations, we also performed theoretical DOS and band structure calculations for the cubic and tetragonal phase, respectively. The results suggest Na-Tl interactions in the second coordination sphere being responsible for the observed tetragonal distortion of Zintl's cubic NaTl. 相似文献