Investigations into TiC Refractory Layers on Steel Surfaces by Means of ESCA Spectra

The investigation of the element composition of TiC_x layers depending on depth profiles shows that the samples stored on air are coated by a contamination layer of hydrocarbons. The subjacent layer consists of about 19 mole-% Ti, 26 mole-% C, 45 mole-% 0 and less than 5 mole-% of Cr and Fe. The change of the position of the C1s, 01s and Ti2p-lines depending on depth profiles allows us to draw conclusions from changes in the chemical bonding states of these elements. — A detailed profile analysis of the C1s-line shows five different bonding states of carbon (C_yH_x, TiC_x, Fe₃C, elemental C and 〉CO-compounds). The change of the O- and Ti-bonding states within the layer consists particularly in decreasing OH-bond as compared with oxide-bond and also of TiO_x in comparison with TiC_x.     

Crystal and molecular structures of N-alkyl-N,N-dimethyl-3-(heptamethyltrisiloxan-3-yl) propylammonium bromides

C₁₆H₄₂NO₂Si₃Br: M_r = 444.76, monoclinic space group P 2₁/c, a = 23.300(8), b = 8.918(4), c = 13.403(2) Å, β = 101.69(4)°, V = 2727(1) ų, D_x = 1.08 Mgm⁻³, D_exp = 1.06 Mgm⁻³, Z = 4, F(000) = 932, λ(MoKα) = 0.71069 Å, μ = 16.3 cm⁻¹. The crystal structure was determined by direct methods and refined by least-squares procedure to the discrepancy factor R = 0.117. C₁₅H₄₀NO₂ Si₃Br: M_r = 430.34, monoclinic space group P2₁/c, a = 23.460(4), b = 8.518(2), c = 13.403(2) Å, β = 102.03(2)°, V = 2619(1) ų, D_x = 1.09 Mgm⁻³, D_exp = 1.07 Mg⁻³, Z = 4, F (000) = 920, λ(MoKα) = 0.71069 Å, μ = 33.9 cm⁻¹. The crystal structure was determined by least-squares refinement of the structure model derived from structure determination of C₁₆H₄₂NO₂·Si₃Br to the discrepancy factor R = 0.099. C₁₆H₄₂NO₂Si₃Br: Daten siehe oben. C₁₅H₄₀NO₂Si₃Br: Daten siehe oben.     

Crystal and Molecular Structure of mer-Co(4-CH3C5H4N)3(N3)3

The crystal structure of mer-Co(4-CH₃C₅H₄N)₃(N₃)₃has been determined by single crystal X-ray methods at 300 K. The compound crystallizes in the monoclinic space group C 2/c, a = 19.087(6), b = 16.769(4), c = 15.845(4) Å, β = 119.04(2)°, V = 4434(2) ų, M_r = 464.42. Z = 8, D_x = 1.391 Mgm⁻³, F(000) = 1920, λ (MoKα) = 0.71069 Å, μ = 0.802 mm⁻¹. The cobalt(III) ions are octahedrally coordinated to three azide groups and to three 4-methyl-pyridine molecules to form isolated coordination polyhedra.     

On the stereochemistry of 7-[1(2-carbomethoxyanilino)-1-(pyridyl)-methyl]-quinolin-8-ol (CMAP-oxine)

C₂₃H₁₉N₃O₃, P1 , a = 11,683(3), b = 7.740(2), c = 14.445(3) Å, α = 131.02(8), β = 95.43(8), γ = 95.02(8)°, D_x = 1.328 Mg · m⁻³, V = 0.9614 · 10⁻²⁷ m³, Final R = 0.059 for 2905 symmetrically independent reflections (|F₀| ≧ 3σ(F₀)). The intensities were measured with an automatic diffractometer. There are two molecules in the unit cell. The substance is not tridentat in potentially coordination behaviour; coordination takes place (twodentat) on the oxine group.     

Crystal and Molecular Structure of 1-Ethyl-3-[tris(trimethylsiloxanyl)silyl]pyrrolinium Hydrochloride

The crystal and molecular structure of 1-Ethyl-3[tris(trimethylsiloxyl)silyl]pyrrolinium hydro-chloride (C₁₅H₃₈N⁺O₃Si₄ · C¹⁻) has been determined by direct methods. The title compound crystallizes in the monoclinic space group C2/c with a = 20.640(3), b = 19.494(2), c = 27.34(3) Å, β = 90.60(4)°, V = 11000(13) ų, Z = 16, D_x = 1.034 Mg m⁻³. There are two molecules with different conformations in the crystal. The pyrroline rings are non-planar.-The Si O Si angles range from 149(1)° to 163(1)°. Two of the SiMe₃ groups are disordered. All molecules are connected by C¹⁻ – N⁺ contacts and C¹⁻ - HN⁺ hydrogen bonds to form double chains.     

Crystal and molecular structure of 7-[1-(2-carbomethoxyanilino)-1-(phenyl)-methyl]-quinolin-8-ol(CMAB-Oxine) and comparising consideration to CMAP-Oxine

C₂₄H₂₀N₂O₃, Pbc2₁, a = 11.338(4), b = 7.786(3), c = 44.381(6) Å, D_x = 1.29 Mg · m⁻³, V = 3.82053 · 10⁻²⁷ m³. There are eight molecules in the unit cell (two molecules, A and B, in the asymmetric unit). The substitution of N (CMAP-Oxine) by CH(CMAB-Oxine) in the aldehyde participant of reactants creates differences both in intermolecular contacts and orientation phenomenons of ring planes. A high degree of selectivity of the substitution position for both compounds is given. The reactions to the synthesis of both compounds are difficult to agree upon with the characteristic feature of the Mannichreaction and corresponded more to the character of the electrophilic substitution of aromatics.     

Static Disorder in Hexagonal Crystal Structures of C60 at 100 K and 20 K

C₆₀ · 2C₈H₁₀ (100 K): hexagonal space group P6₃, a = 23.694(4), c = 10.046(2) Å, V = 4884(2) ų, D_x = 1.903 g cm⁻³, Z = 6, F(000) = 2856, γ(CuKa) = 1.54178 Å, μ = 0.84 mm⁻¹. C₆₀ · 2C₈H₁₀ (20 K): hexagonal space group P6₃, a = 23.67(1), c = 10.02(1) Å, V = 4862(6) ų, D_x = 1.912 g cm⁻³, Z = 6, F(000) = 2856, γ(CuKa) = 1.54178 Å, μ = 0.84 mm⁻¹. The structures were determined by Patterson syntheses and rigid-body refinements. The C₆₀ molecules show two orientations with one molecular centre in common. The solvent molecules are disordered too. Static disorder could not be overcome or influenced by cooling down. A coordination number of 10 was found for the fullerene molecules.     

Nitrido-phthalocyanine-rhenium (V) structure and absorption spectra

The crystal structure of nitrido-phthalocyanine-rhenium (V) has been determined from X-ray diffraction date. The crystal data are: C₃₂H₁₆N₉Re (tetragonal), a = 1.775 nm, c = 1.386 nm, Z = 4, ϱ = 2.23 g cm⁻³. Optical and infrared absorption spectra have been measured on sublimated films and compared with the corresponding spectra of other metal phthalocyanines.     

Structures of Azomethine Imines of the Pyrazolidone-(3)-type, (III) The Structure of 1-[Anthryl-(9)-methylene]-pyrazolidone-(3)-betaine

C₁₈H₁₄N₂O, Pbca, a = 19.541(4) Å, b = 14.800(2) Å, c = 9.572(3) Å, Z = 8, U = 2768.3 ų, D_x = 1.32 g cm⁻³, μ(MoKα) = 0.93 cm⁻⁻¹, crystal size 0.5 × 0.2 × 0.1 mm, colourless. Final R = 0.077 for 1177 independent reflections excluded those with |F₀| < 8 σ(F₀). The intensities were measured with an automatic diffractometer. The azomethine imine unit of the molecule has a geometry in approximate agreement with a polymethinic electron structure. The conjugation of the azomethine imine unit with the anthryl unit is only small. The anthryl ring and the five membered pyrazolidone ring include a dihedral angle of 65.4°. The main intermolecular forces are C–H … N hydrogen bridges.     

The Crystal and Molecular Structure of 2-(2′-Cyano-2′-amido-ethylenyl)-pyridine

The title compound (C₉H₇N₃O) has been determined from three dimensional X-ray diffraction data. The crystals are monoclinic, a = 4.858(3) Å, b = 15.008(7) Å, c = 11.787(2) Å, ß = 94.107(2)°, V= 857.2(4) ų, z = 4, D_calc = 1.342 g. cm⁻³, space group P2_1/c. The structure was solved by direct methods and refined by full-matrix least-squares method (γ MoK_α′, R = 0.0766).     

The crystal and molecular structure of three homologue 1,4-dialkanoyloxy-biphenyls (SYM-n)

The three homologue compounds with the general formula C_nH_2n+1 COO C₆H₄ C₆H₄ OOC C_nH_2n+1 (SYM-n) crystallize in the following space groups: SYM-1: triclinic, P1 , a = 7.400(6), b = 9.227(3), c = 10.579(3) Å, α = 85.97(3), β = 89.09(3), γ = 71.47(3)°; SYM-2; monoclinic, P2₁/c, a = 11.712(7), b = 5.648(1), c = 12.408(6), Å, β = 103.84(3)°; SYM-5: triclinic, P1, a = 5.505(4), b = 8.342(8), c = 24.79(2) Å, α = 86.67(3), β = 85.45(6), γ = 71.74(7)°. The structures have been solved by direct methods and refined to R = 0.075, 0.061 and 0.053, respectively. The packing arrangements show a layer-like structure. The layers are almost separated for SYM-1 as well as for SYM-2 and interdigitated for the structure of SYM-5.     

1,3,5-trichlorotricyanobenzene complexes with mesitylene (1/1) and benzene (1/3)

Trichlorotricyanobenzene-mesitylene (1/1) is monoclinic, space group P2₁/n; at −88°Ca=10.509(3),b=14.863(7),c=11.518(3) ?, β=99.38(2)⁰,V=1775(2) ?³,D _x =1.409(2) g cm⁻³,Z=4. Trichlorotricyanobenzene-benzene (1/3) is hexagonal, space group ; at −99°Ca=17.3914(3),c=7.2673(1) ?,V=1903.6(1) ?³,D _x =1.2844(1) g cm⁻³,Z=3. In both complexes there are stacks of alternating trichlorotricyanobenzene and hydrocarbon molecules. In both complexes there are sheets of molecules perpendicular to the stacks. In the mesitylene complex these sheets contain equal numbers of both kinds of molecules with the trichlorotricyanobenzene molecules arranged in tapes. In the benzene complex the sheets contain only one kind of molecule or the other. The sheets containing the trichlorotricyanobenzene molecules have approximately linear C−N...Cl−C intermolecular interactions with N...Cl distances about 3.02 ?.     

Crystal and molecular structure ofcis-dicarbonyltetraphosphinechromium(O), [(CO)2(PH3)4Cr]

The crystal and molecular structure ofcis-dicarbonyltetraphosphinechromium(O), [(CO)₂(PH₃)₄Cr] has been determined by X-ray diffraction methods. The compound crystallizes in the monoclinic system: space groupC2/c,a = 6·968(6),b = 11·98(1),c = 12·87(1) Å, = 99·80(8) °,V= 1059(3) ų,Z=4,D _m = 1·534(5),D _x = 1·531(5) gcm^–3, diffraction symmetry 2/m. The structure was solved by conventional methods, and refined by least-squares techniques to an agreement factorR = 0·078. The chromium atoms lie on rotation diads, and thus the molecules must have at least the symmetry 2(C ₂); they were found to have, within the limits of accuracy, the even higher symmetrymm2 (C _2v ). There are two distinct independent Cr-P distances in the molecule, the Cr-P bonds where phosphorus istrans to carbonyl [2·338(4) Å] being significantly longer than those where phosphorus istrans to phosphine [2·282(4) Å]. This difference may be attributed to a difference in the back-bonding capabilities of the two types of ligands.We wish to thank Professor Dr E. O. Fischer for his stimulating interest in this work. Our thanks are due also to the Leibniz Rechenzentrum der Bayerischen Akademie der Wissenschaften for use of their computing facilities. This work would not have been possible without a generous grant from the Deutsche Forschungsgemeinschaft which is gratefully acknowledged.     

Liquid-Phase Epitaxy of (Hg,Cd)Te on CdTe Substrates by a Vertical Dipping Technique

Hg_1−xCd_xTe layers on CdTe substrates were grown from Te-rich melt solutions by a vertical dipping technique using a special quasi-closed system with ground-glass sealing. Results are good reproducibilities of the electrical properties after annealing in Hg-rich atmosphere (p77 ≈ 2 · 10¹⁶ cm⁻³ μ77 ≈ 500 cm² V⁻¹ s⁻¹) and of the x-value, respectively. A horizontal position of the substrate downwards to the melt solution yields, in difference to a vertical one, to homogeneous layer thicknesses. Short meltback steps before growth leads to sharper profiles of composition.     

Crystal Structure,Thermal Analysis and IR Spectroscopic Investigation of Bis Benzyl Ammonium Monohydrogentetraoxoarsenate(V) Monohydrate

Abstract  

The salt bis benzyl ammonium monohydrogentetraoxoarsenate(V) monohydrate [C₆H₅CH₂NH₃ ⁺]₂HAsO₄ ²⁻·H₂O, M = 373.92, Triclinic, P−1. a = 6.514(1), b = 8.910(2), c = 15.061(3) ?, α = 99.26(2), β = 93.93(1), γ = 97.64(1)°, V = 851.5(3), Z = 2, D _x  = 1.460, λ (MoKα) = 0.71073 ?, μ = 0.99 mm⁻¹, F(000) = 126, T = 20(2)  °C, final R = 0.673 for 5488 unique reflections. Planes of HAsO₄ ²⁻ alternate with planes of C₆H₅CH₂NH₃ ⁺ groups. The structure consists of infinite parallel two-dimensional planes built of mutually connected ions and water molecules by strong O–H···O and N–H···O hydrogen bonding. There are no contacts other than van der Waals interactions between the layers. Differential scanning calorimetry study on bis benzyl ammonium monohydrogentetraoxoarsenate(V) monohydrate was carried out. The infrared of polycrystalline samples of this compound have been recorded at room temperature.     

EXAFS and XANES Studies on 3d Transition Metal Intercalation Compounds M x TiS2

Abstract

EXAFS and XANES spectra of Ti K-edge have been measured for 3d transition metal intercalation compounds M _x TiS₂ (M = Mn, Fe, Co and Ni; x ≤ 0.33). We have found that the interatomic distance between Ti and the first nearest neighbor S atoms, R(Ti-S), increases with the guest concentration x. The variation in XANES spectra with x reveals the reduction of the valence state of Ti atoms upon intercalation of M. From these results as well as the M K-edge EXAFS data studied previously, we have proposed a simple model on the local structure of M _x TiS₂ to reproduce the observed values of R(Ti-S) by averaging local shift of S atoms caused by intercalation.     

Crystal structure of 3,3-(p-N,N-dimethylaminophenyl)-6-N,N-dimethylaminophthalide, (crystal-violet lactone)

The title compound is C₂₆H₂₉N₃0₂,M _r ,=415.54, monoclinic,P2₁/n,a=12.228(1),b=17.385(2),c=11.786(1) Å,V _c =2308.7 Å₃,Z=4,D _x =1.19 Mg m^–3,=5.29 cm^–1,F(000)=888. FinalR=0.046 for 2301 independent reflections. Three cyrstallographically distinct nitrogens were found, with the molecule possessing the expected propeller shape.     

Crystal and molecular structure of dichlorotetrakis(propanol-2) titanium (III) chloride,C12H32Cl3O4Ti

The crystal and molecular structure of dichlorotetrakis(propanol-2)titanium (III) chloride, C₁₂H₃₂Cl₃O₄Ti, has been determined by X-ray methods. The complex crystallizes in the monoclinic system:a = 15.968(4),b = 11.610(5),c = 11.90(5) Å, = 94.15(2) °, space groupC2/c andZ = 4. The positions of all non-hydrogen atoms have been refined by least squares to giveR = 0.126 for 1211 observed structure factors. The crystal structure consists of {TiCl₂(HOCH(CH₃)₂)₄}⁺ cations and Cl^– anions. From the space-group symmetry, it follows that the complex cation has 2(C ₂) symmetry. The 2 chlorine and 4 oxygen atoms of the inner coordination sphere are arranged in the form of a distorted octahedron around the central Ti atom. Two chlorine atoms, with the interatomic distance Ti—Cl of 2.32 Å, are in acis-conformation. The interatomic distances Ti—O, two oxygen atoms opposite to the chlorine atoms, are 2.10 Å. The pair oftrans-oriented oxygen atoms are at distances Ti—O= 2.09 Å. The Cl^– ions occupy positions at symmetry centres. Each of them is in contact with four oxygen atoms, the paired Cl—O distances being 3.04 Å and 3.12 Å.     

Crystal and molecular structure determination,TGA-DTA,and infrared and Raman spectra of rubidium nitroprusside,Rb2[Fe(CN)5NO]

The title compound, Rb₂[Fe(CN)₅NO], crystallizes in the space group P2₁2₁2₁, witha=5.687(1),b=15.956(2),c=12.645(3) Å, andZ=4. Anions are in equivalent C₁ sites (one per asymmetric unit) and are slightly distorted octahedra (C_4v ideal symmetry). TGA and DTA curves and vibrational (infrared and Raman) spectra of Rb₂[Fe(CN)₅NO] were obtained. Results are interpreted in view of the crystal structure of the compound and the behavior of related substances.     

Crystal and molecular structure of 5-diazo-2,2-dimethyl-4,6-dioxo-1,3-dioxane and 5-diazo-1,3-dimethylpyrimidin-2,4,6-trione

C₆N₂O₄H₆: M_r = 170.12, orthorhombic space group Pbca, a = 6.751(2), b = 13.669(4), c = = 16.845(4) Å, V = 1555(1) ų, D_x = 1.248 Mgm⁻³, Z = 8, F(000) = 704, λ(moKα) = 0.71069 Å, μ = 1.1 mm⁻¹. The crystal structure was determined by direct methods and refined by least-squares procedure to the discrepancy factor R = 0.039. C₆N₄O₃H₆: M_r = 182.14, monoclinic space group C2/c, a = 17.726(8), b = 6.191(12), c = 16.062(6) Å, β = 117.59 (3)°, V = 1562 (1) ų, D_x = 1.549 Mgm⁻³, Z = 8, F(000) = 752, λ(MoKα) = 0.71069 Å, μ = 1.2 mm⁻¹. The crystal structure was determined by direct methods and refined by least-squares procedure to the discrepancy factor R = 0.056.