首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 703 毫秒
1.
Crystals of decafluorofluoranthene, C16F10, are monoclinic, space group C2/c with unit cell dimensions a = 18.92(1), b = 4.84(1), c = 29.01(2) Å, β = 105.34(5)°. The structure was refined to a conventional discrepancy factor R of 4.7% and weighted discrepancy factor Rw of 4.9% for 1841 observed counter amplitudes. Estimated standard deviations average 0.004 Å; for bond lengths and 0.3° for bond angles. The molecule is essentially planar. Detailed comparison with the parent hydrocarbon indicates that substitution of fluorine for hydrogen has brought about only quite small changes in molecular geometry.  相似文献   

2.
Crystals of the title compound are tetragonal, with unit cell dimensions a = b = 6.10(1), c = 37.16(2) Å, space group P41212. The structure has been determined from 780 three-dimensional counter data and refined to a value of 4.5% for the conventional discrepancy factor R. Estimated standard deviations average 0.006 Å for bond lengths and 0.5° for bond angles. The molecule has C2 symmetry. The symmetry-related aromatic rings are each inclined at an angle of 61° to the C-S-C plane. The length of the C-S bond, 1.771(4) Å, corresponds closely to that expected for a single bond between sulphur and sp2-hybridized carbon. The bond angle at sulphur is 99.7(3)°, some 4° smaller than the angle in unfluorinated diaryl sulphides.  相似文献   

3.
The syntheses and the crystal structures of the complexes Co2(BAMP)Cl4 ( 1 ) and [Cu(BAMP)(H2O)](ClO4)2 (2 ) are reported. 1 crystallizes in the monoclinic space group C2/c with the unit cell dimensions a = 3129.7(4), b = 772.9(1), c = 1503.4(2) pm, β = 112.47(1)° and Z = 4. Cobalt(II) is surrounded in the fashion of a distorted tetrahedron built from the NO donor atoms of the BAMP ligand and two chloride anions. The copper compound 2 crystallizes in the monoclinic space group I2/a with unit cell dimensions of a = 2539.0(3), b = 1448.1(1), c = 1887.0(2) pm, β = 93.40(1)° and Z = 8. Copper(II) coordination can be described as a square-based pyramid with the N2O2 donor atoms of the BAMP molecule forming the basal plane completed by a water molecule in the apical position. Spectroscopic (IR and UV-Vis) and conductivity data of the new complex compounds are presented.  相似文献   

4.
The syntheses and crystal structures of the first cyanide, sulfur mixed ligand copper(I) complexes are reported. The first complex of the family was discovered when (CuCN)(3)(C(6)H(12)N(4))(2) (1) (C(6)H(12)N(4) = hexamethylenetetramine) was treated with aqueous thiourea. The sulfur ligands include thiourea (tu), 1,3-dimethyl-2-thiourea (dmtu), 1,3-diethyl-2-thiourea (detu), 1,1,3,3-tetramethyl-2-thiourea (tmtu), and 2-imidazolidinethione (N,N'-ethylenethiourea, etu). Synthesis was effected by adding the ligand to a solution of CuCN in aqueous sodium thiosulfate. Complex 2, (CuCN)(2)(tu)(3)(H(2)O), crystallizes in the triclinic space group P&onemacr;with unit cell dimensions a = 7.696(5) ?, b = 9.346(2) ?, c = 10.772(2) ?, alpha = 106.53(2) degrees, beta = 91.11(4) degrees, gamma = 98.42(3) degrees, and Z = 2. Complex 3, (CuCN)(3)(dmtu)(2), crystallizes in the monoclinic space group Cc with unit cell dimensions a = 10.082(3) ?, b = 14.984(5) ?, c = 11.413(3) ?, beta = 104.50(2) degrees, and Z = 4. Complex 4, (CuCN)(2)(detu)(H(2)O), crystallizes in the monoclinic space group P2(1)/n with unit cell dimensions a = 7.969(5) ?, b = 11.559(4) ?, c = 13.736(5) ?, beta = 100.48(4) degrees, and Z = 4. Complex 5, (CuCN)(tmtu) (polymorph a), crystallizes in the orthorhombic space group P2(1)2(1)2(1) with unit cell dimensions a = 8.653(1) ?, b = 9.426(1) ?, c = 11.620(3) ?, and Z = 4. Complex 6, (CuCN)(tmtu) (polymorph b), which has the same connectivity as 5, crystallizes in the triclinic space group P&onemacr; with unit cell dimensions a = 9.660(4) ?, b = 14.202(4) ?, c = 16.03(1) ?, alpha = 101.68(5) degrees, beta = 107.08(6) degrees, gamma = 70.07(2) degrees, and Z = 8. The difference between the polymorphs is that 5 has a zig-zag chain with a repeat unit of two while 6 has a 4-fold helix. Complex 7, (CuCN)(2)(etu), crystallizes in the monoclinic space group P2(1)( )()with unit cell dimensions a = 3.994(2) ?, b = 13.886(3) ?, c = 7.556(1) ?, beta = 97.07(2) degrees, and Z = 2.  相似文献   

5.
<正> The compound Ni2Nb2Te4 crystallizes in orthorhombic system,space group Pma2 with cell dimensions a = 7.955(1),b=6.258(1),c=7.202(2)A,and Z=2.X-ray structural determination showed the non-molecular 2-dimensional character of the title compound. In each structural unit, the two Ni and two Nb atoms form a rhombic plane with four Ni-Nb bonds (average 2.675 A) and one Ni-Ni bond (2.536 A) and there exists no Nb-Nb interaction. The distorted tetrahedral coordination of each metal atom is completed by four Te atoms. The average distances are 2.799A for Nb-Te bonds and 2.560A for Ni-Te bonds.  相似文献   

6.
Single crystals of 2,4,6,6-tetrachloro-2,4-bis(piperid-yl)cyclotri(phosphazene) ( 1a ) and of 2,4,6-trichloro-2,4,6-tris(piperidyl)cyclotri(phosphazene) ( 2a ) were grown from petroleum ether solution. The structures of both compounds were determined by single-crystal X-ray diffraction analyses. Compound 1a crystallizes in the monoclinic space group P 21/n with Z = 4 and unit cell dimensions a = 9.3994(4), b = 19.204(3), c = 11.5664(4) Å, and β = 108.718(4)°. Compound 2a crystallizes in the triclinic space group P 1 with Z = 4 and unit cell dimensions a = 12.8289(2), b = 13.8856(2), c = 14.63810(10) Å, and α = 100.7621(5), β = 91.0094(2), γ = 113.9757(6)°. The experimentally obtained structural parameters for the covalent molecules 1a and 2a compare well with those calculated at the semiempirical PM3 level of theory. These results give credence to the PM3 calculated structures of 2,4,6,6-tetraazido-2,4-bis(piperidyl)cy-clotri(phosphazene) ( 1b ) and 2,4,6-triazido-2,4,6-tris(piperidyl)cyclotri(phosphazene) ( 2b ) for which presently there are no experimental data available.
  • 1 Non-SI units employed: 1 kcal≈︁4.184 kJ, 1 Å = 10−10 m (since these units are still used in computational chemistry, we employed them throughout this article).
  • © 1997 John Wiley & Sons, Inc. Heteroatom Chem 8: 267–271, 1997.  相似文献   

    7.
    The crystal structure of the α form of 3-hydroxy-5-phenylisoxazole has been determined from three-dimensional X-ray data. The crystals are monoclinic, space group P21/n with four molecules in the unit cell. The cell dimensions are: a = 10.41(2); b = 3.89(1); c = 19.14(4) Å; β = 96.1° (3). The structure was refined by the block-diagonal least-squares method to a final R value of 0.080 for 1111 observed reflections. The molecular dimensions are in good overall agreement with those in β form, while the packing is markedly different. Conjugation and planarity in the molecule are discussed.  相似文献   

    8.
    The reaction of 4-amino-6-methyl-1,2,4-triazine-3(2H)-thione-5-one (AMTTO, 1 ) with palladium(II) chloride in acetonitrile/methanol leads to the N,S-coordinated complex [Pd(η2-AMTTO-N,S)Cl2] · CH3OH ( 2 ). 2 has been characterized by IR and MS techniques. The ligand 1 and the complex 2 were also investigated by X-ray structure determinations. 1 crystallizes in the space group P1¯ with the lattice dimensions at –70 °C: a = 419.6(1), b = 598.2(1), c = 1351.3(1) pm, α = 92.23(1), β = 91.20(1), γ = 100.51(1)°, Z = 2, R1 = 0.0441. 2 crystallizes in the space group P21/c with the lattice dimensions at 20 °C: a = 683.3(1), b = 1323.0(1), c = 1254.2(1) pm, β = 92.61(1)°, Z = 4, R1 = 0.0361. According to the structure analysis 1 consists of planar C,N-heterocycles connected by hydrogen bridges forming an infinite chain along [110]. The basic heterocyclic skeleton of 2 is essentially planar and linked three-dimensionally through hydrogen bridges.  相似文献   

    9.
    Phosphoraneiminato Complexes of Hafnium. Crystal Structures of [Hf(NPPh3)4] · 3 THF and [Hf(NPPh3)2Cl2(HNPPh3)2] The phosphoraneiminato complexes [Hf(NPPh3)4] · 3 THF ( 1 · 3 THF) and [Hf(NPPh3)2Cl2(HNPPh3)2] ( 2 ) have been prepared as colourless, moisture sensitive single crystals by reactions of hafnium tetrachloride with [CsNPPh3]4 · 2 toluene in tetrahydrofurane solutions by application of different ratios of the educts. Both complexes are characterized by IR spectroscopy and X‐ray crystal structure determinations. 1 · 3 THF: space group P 1, Z = 4, lattice dimensions at 193 K: a = 2007.6(1); b = 2064.2(1); c = 2115.9(1) pm; α = 109.193(4)°; β = 111.285(4)°; γ = 96.879(4)°; R1 = 0.0506. 1 forms monomeric molecules with tetrahedral coordination of the nitrogen‐atoms of the (NPPh3)‐groups towards the Hafnium atom. The HfN distances of 200.9 pm in average correspond with double bonds. 2 : space group P 1, Z = 4, lattice dimensions at 193 K: a = 1444.0(1); b = 1928.1(1); c = 2455.8(2) pm; α = 67.273(8)°; β = 87.445(8)°; γ = 87.082(8)°; R1 = 0.0312. 2 has a monomeric molecular structure with octahedral coordination of the hafnium atom. The chlorine atoms are in trans position to one another, whereas the nitrogen atoms of the phosphoraneiminato groups (NPPh3) are in trans position towards the nitrogen atoms ot the phosphorane imine molecules (HNPPh3). The HfN bond lengths of the (NPPh3) groups of 199.7 pm in average correspond with double bonds, whereas the HfN distances of the HNPPh3 molecules with bond lengths of 230.2 pm in average are of donor‐acceptor type.  相似文献   

    10.
    2,2′-Sulfinyl-bis(4-methyl phenol) 3 and it's thio derivative have been synthesized in this work. The reduction process of sulfoxide 3 to its thio derivative 5 was accomplished in the presence of Zn/AcOH/SiO2, under microwave irradiation. The structures have been confirmed by spectroscopic (IR, 1HNMR, 13CNMR) and single crystal x-ray diffraction methods. 2,2′-Sulfinyl-bis(4-methyl phenol) 3 crystallizes in the space group Cc of the monoclinic system with four molecules in the unit cell of dimensions a = 11.425(2) Å, b = 13.530(2) Å, c = 9.5215(17) Å, β = 117.289(4) Å, and 2,2′-thio-bis(4-methyl phenol) 5 crystallizes in the space group P 212121 of the orthorhombic system with four molecules in the unit cell of dimensions a = 9.021(1) Å, b = 10.523(2) Å, c = 13.607(2) Å, α = 90. The structures have been refined to final values for the crystallographic R factor of 0.0189(3) and 0.0248(5) based on 2999 and 3720 observed independent reflections respectively.  相似文献   

    11.
    Tin(IV) Complexes with Tridentate Diacidic Ligands By template reactions including bis(acetylacetonato)-dichloro-tin(IV) and O-aminophenol as well as o-aminothiophenol, benzoylhydrazine, and thiobenzoylhydrazine the tin chelates of tridentate diacidic ligands containing ligator atoms were prepared. To characterize the compound, IR, UV-VIS and Mössbauer spectroscopy were used. Crystal structure analyses demonstrate the existence of disturbed octahedral structures. Bis[acetylacetonbenzoylhydrazonato(2-)]tin(IV): space group P21/c, Z = 4, 2501 observed unique reflections, R = 0.045. Lattice dimensions at 20°C: a = 992.3, b = 2405.5, c = 1071.8pm, β = 116.94°. Bis[acetylacetonthiobenzoylhydrazonato(2-)] tin(IV): space group P21/c, Z = 4, 3603 observed unique reflections, R= 0.029. Lattice dimensions at 20°C: a = 1581.5, b = 947.8, c = 1644.9pm, β = 90.32°.  相似文献   

    12.
    Alkali Metal Phosphoraneiminates. New Syntheses and Crystal Structures of [RbNPPh3]6 and [CsNPPh3]4 The alkali‐metal phosphoraneiminates MNPPh3 with M = Na, K, Rb, Cs have been synthesized by reactions of Ph3PI2 with the alkali‐metal amides in liquid ammonia and were obtained as pure samples by subsequent extraction with toluene. The ethyl derivative KNPEt3 has been prepared by an analogous route from Et3PBr2 and extraction with hexane. Single crystals of the phosphoraneiminates of rubidium and cesium are obtainable by crystallization from toluene and toluene/hexane, respectively. They were suitable for crystal structure determinations. [RbNPPh3]6 · 41/2 toluene ( 1 ): space group P1, Z = 2, lattice dimensions at 193 K: a = 1525.5(2); b = 1902.9(2); c = 2178.3(2) pm; α = 95.435(12)°; β = 91.145(12)°; γ = 90.448(12)°; R1 = 0.0529. The compound forms a Rb6N6 skeleton of a double cube with a common face of two rubidium and two nitrogen atoms, the latter being fivefold coordinated by four rubidium atoms and the phosphorus atom. [CsNPPh3]4 · 2 toluene · 33/4 hexane ( 2 a ): space group Fd3, Z = 8, lattice dimensions at 123 K: a = b = c = 2679.7(1) pm; R1 = 0.0405. [CsNPPh3]4 · 2 toluene ( 2 b ): space group P21/n, Z = 4, lattice dimensions at 193 K: a = 1418.9(1); b = 2258.9(1); c = 2497.6(1) pm; β = 91.055(6)°; R1 = 0.0278. Both cesium compounds form Cs4N4 heterocubane structures which are different by means of the packing and by different bond angles at the cesium and nitrogen atoms.  相似文献   

    13.
    A new complex of a chiral monoaza-crown ether, [R-(-)-2-ethyl-N-benzyl-4,7,10,13-tetraoxa-1-azacyclopentadeceane) NaClO4], has been prepared and studied by x-ray diffraction. The compound crystallizes in space group P21 with cell dimensions a = 9.480(1), b = 15.978(2), c = 15.816(2) Å, = 105.51(1)°, Z = 4. The final R value is 0.055 for 2711 observed reflections and 540 parameters. There are twomolecules in the asymmetric unit labelled A and B. The sodium ion is hexacoordinated. The average values for the Na–-Oeth (etheric) distances are 2.364(6), 2.317(7) Å and the Na–N distances are 2.679(6), 2.611(7) Å; the Na–-O(ClO4) contacts are2.497(7) and 2.257(10) Å, for A and B, respectively.  相似文献   

    14.
    Two novel two‐dimensional (2D) coordination polymers of stoichiometry [{PhS(CH2)4SPh}Hg2X4]n (X = Cl, 2a ; X = Br, 2b ) have been prepared by treatment of HgX2 with PhS(CH2)4SPh 1 , acting as bridging dithioether ligand. The extended 2D structures result from bridging coordination of 1 between two mercury atoms and intermolecular Hg–X interactions, thus linking the HgX2 units in two dimensions. As established for 2a,b by single‐crystal X‐ray diffraction, the coordination around the Hg centers in both isomorphous compounds (monoclinic, space group P21/c) is distorted tetrahedral, with quite short Hg‐thioether bonds of 2.4780(19) ( 2a ) and 2.499(3) Å ( 2b ), respectively.  相似文献   

    15.
    <正> The title compound belongs to triclinic system, space group PI, with dimensions: a = 9.237(1), b = 9.589(1), c = 10.424(1) A ; <*= 72.09(2)?ft- 88.79(2)? 3r=80.28(l)? Z = 2, V = 865.5 A3, Dx = 2.626 gcnr3. Final R = 0.026 and Rw = 0.036 for 2531 reflections.  相似文献   

    16.
    The reactions of K(2)PtCl(4) with N,N'-diphenylformamidine (HDPhF) and N,N'-di-p-tolylformamidine (HDTolF) produce the trans square-planar compounds PtCl(2)(HDPhF)(2), 1a, and PtCl(2)(HDTolF)(2), 1b. Compound 1a crystallizes as yellow parallelepipeds in the space group P2(1)/c with two independent molecules in the asymmetric unit and unit cell dimensions a = 23.427(7) ?, b = 16.677(6) ?, c = 12.980(4) ?, and beta = 96.10(2) degrees. These compounds are soluble in common organic solvents and have been used as starting materials for the preparation of diplatinum compounds. Treatment of 1a and 1b with NaOMe and the halide abstraction reagent TlPF(6) produces the compounds Pt(2)(&mgr;-DArF)(2)(eta(2)-DArF)(2), Ar = Ph (2a) and Tol (2b), respectively. Compound 2a crystallizes as yellow rods in the space group P&onemacr; with unit cell dimensions a = 12.296(3) ?, b = 12.310(4) ?, c = 15.374(4) ?, alpha = 90.75(2) degrees, beta = 91.02(2) degrees, and gamma = 110.20(2) degrees. Compound 2b crystallizes with a molecule of THF, as yellow rods in the space group P2(1)/c with a = 17.883(3) ?, b = 14.517(3) ?, c = 22.581(3) ?, and beta = 98.17(1) degrees. These compounds contain two cis bridging formamidinato ligands and two formamidinato ligands that are chelated to separate Pt centers. Upon heating, they further react to give the tetrabridged compounds Pt(2)(&mgr;-DArF)(4), Ar = Ph (3a), Tol (3b). Compound 3a crystallizes as orange cubes in the cubic space group I432 with a = 19.671(1) ?. On going from the bis-bridged, bis-chelate structure in 2a to the tetrabridged structure in 3a, the metal-metal separation decreases from 2.910(1) to 2.649(1) ?. Both 2band 3b have been oxidized to give the Pt(II)-Pt(III) compound Pt(2)(&mgr;-DTolF)(4)(PF(6)), 4. Compound 4 crystallizes as cubes in the tetragonal space group P4/ncc with a = 14.392(1) ? and c = 14.436(1) ?. The Pt-Pt distance in 4 is 2.5304(6) ?.  相似文献   

    17.
    The crystal structures of [Pt(NH3)2CPrDCA].H2O (I), [Pt(CH3NH2)2CPrDCA] (II), and [Pt(dmbn) CPrDCA].2.5H2O (III) (where CPrDCA is 1,1-cyclopropanedicarboxylate; dmbn is 2,3-dimethyl-2,3-butyldiamine) are determined. Compound I crystallizes in the orthorhombic space group Pnma with the cell dimensions: a = 6.517(2), b = 9.709(3), c = 14.205(5) A, Z = 4, R = 0.058. Compound II is monoclinic with space group P2(1)/n, a = 9.648(3), b = 8.720(2), c = 12.770(4) A, beta = 107.12(2), Z = 4, R = 0.059. Compound III belongs to the monoclinic system space group P2(1)/m with the cell dimensions: a = 6.494(1), b = 19.638(3), c = 6.606(1)A, beta = 94.44(1), Z = 2, R = 0.038. Electronic structures of the complexes are studied and the correlation between structure of the amine ligands and biological activity of the complexes is explored.  相似文献   

    18.
    The 1,3-dipolar cycloaddition of 3-phenylsydnone with p-toluquinone afforded 5-methyl- and 6-methyl-2-phenyl-2H-indazole-4,7-diones 3a and 3b. No regioselectivity was observed in this cycloaddition yielding an equimolar amount of the regioisomers. Reactions of 3a and 3b with bromine gave the corresponding mono- 4a and 4b and dibromo derivatives 5a and 5b , respectively. The crystal structure of 6-bromo-5-methyl-2-phenyl-2H-indazole-4,7-dione ( 4a ) has been determined by the single crystal X-ray method. The crystals are monoclinic, space group PI with two molecules in a unit cell of dimensions a = 8.029(1), b = 14.309(1), c = 5.895(1)Å, β = 90.24(1)° and V = 621 Å3. The structure has been solved by the direct method using 1827 reflections and refined by full-matrix least-squares calculations to R = 0.0739.  相似文献   

    19.
    A new MC simulation method is proposed for the controlled/living radical polymerization in a dispersed medium, assuming an ideal miniemulsion system. This tool is used to consider the effects of particle size on the polymerization rates and the molecular weight distributions. For NMP, the polymerization kinetics are basically governed by two conflicting factors, (i) the confined space effect that promotes the coupling reaction between a radical and a trapping agent and (ii) the isolation effect of radicals into different particles that suppresses the overall frequency of bimolecular termination. For RAFT polymerization, a significant rate enhancement by reducing the particle size could be observed only for the systems with fast fragmentation of adduct radicals.

      相似文献   


    20.
    The crystal and molecular structure of the four-coordinate complex Ni(C22H22N4) containing the tetramethyldibenzotetraaza[14] annulene ligand has been determined from three-dimensional X-ray diffraction data. The complex crystallized in the monoclinic space group C2h5-P21/n with cell dimensions a=14.7967(10), b=11.2169(6), c=11.4510(6) Å, and β=98.467(5)° with Z=4. The final agreement indices from the least-square refinement of 245 variables with 3111 observations F>3σ(F), are R=0.050, Rw=0.037. The structure has a pronounced saddle-shaped conformation with Ni atom at the saddle point coordinated to four nitrogen atoms. The average Ni-N distance is 1.866(3) Å. The delocalized propane-1,3-diiminato chelate rings and the benzene rings are linked by nominally single C-N bonds.  相似文献   

    设为首页 | 免责声明 | 关于勤云 | 加入收藏

    Copyright©北京勤云科技发展有限公司  京ICP备09084417号