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1.
Contributions on the Thermal Behaviour of Sulfates. VIII. The Chemical Vapour Transport of FeSO4 with NH4Cl and Fe2(SO4)3 with Cl2 or NH4Cl. Experiments and Calculations Well shaped crystals of FeSO4 and Fe2(SO4)3 can be grown by CVT (T1? 650°C). We investigated the dependence of the transport rate on the concentration of the transport agent (Fe2(SO4)3/Cl2 and Fe2(SO4)3/NH4Cl) as well as on the temperature (FeSO4/NH4Cl and Fe2(SO4)3/Cl2). Using ΔfH(FeSO4) = ?220 kcal/ mol, Cp(T) = 30.1 + 9.9 · 10?3 ×T and ΔfH(Fe2(SO4)3) = ?615.4 kcal/mol a satisfying agreement between thermodynamical calculations and experimental results can be reached  相似文献   

2.
On Alkaline Earth Oxocuprates VIII. About Sr2CuO2Cl2 Sr2CuO2Cl2 was prepared and investigated by single crystal X – ray work (space group D–Immm, a = 3.975, c = 15.618 Å). Sr2CuO2Cl2 is isotypic with K2NiF4 – compounds and shows an octahedral configuration for Cu2+. Cl? occupies trans-positions of the octahedral Cu2+/O2? polyhedron. A discussion with related compounds (Sr2CuO3 and Nd2CuO4) explains the observed distribution of O2? and Cl?.  相似文献   

3.
About Ba10Fe8Pt2Cl2O25 The crystal structure of Ba10Fe8Pt2Cl2O25 has been solved by direct methods, using intensity data collected by means of an automatic diffractometer (MoKα). It crystallizes in the hexagonal space group D–P63/mmc: a = 5.8034(4) Å, c = 24.997(5) Å, Z = 1. Fe3+ ions occur in both octahedral and tetrahedral coordination. Two types of Ba2+ ions are formed, with ten and twelve neighbouring atoms. The structure consists of plane connected FeO6 and PtO6 octahedra which are connected by corner shared FeO4 tetrahedra.  相似文献   

4.
LaCl(BO2)2 and Er2Cl2[B2O5]: Two Chloride Oxoborates of Trivalent Lanthanides Er2Cl2[B2O5] is obtained as single crystals by the reaction of ErCl3, Er2O3 and B2O3 with an excess of ErCl3 as flux in evacuated silica tubes after two weeks at 850 °C. The compound crystallizes as long, pale pink needles and appears to be air‐ and water‐resistant. Single‐crystalline LaCl(BO2)2 emerges from the reaction of La2O3, LaCl3, and B2O3 with an excess of B2O3 as flux in evacuated silica tubes after four weeks at 900 °C. LaCl(BO2)2 crystallizes as thin, colourless, air‐ and water‐resistant needles which tend to severe twinning due to their fibrous habit. The crystal structure of Er2Cl2[B2O5] (orthorhombic, Pbam; a = 1489.65(9), b = 1004.80(6), c = 524.86(3) pm; Z = 4) contains two crystallographically different erbium cations. (Er1)3+ resides in pentagonal‐bipyramidal coordination of seven anions while (Er2)3+ is surrounded by only six anions with the shape of an octahedron. The planar oxodiborate units [B2O5]4— consisting of two vertex‐shared [BO3]3— triangles are isolated according to {([BOO]2)4—}. LaCl(BO2)2 crystallizes isostructurally with PrCl(BO2)2 in the triclinic space group P1¯ (a = 423.52(4), b = 662.16(7), c = 819.33(8) pm; α = 82.081(8), β = 89.238(9), γ = 72.109(7)°; Z = 2). The characteristic unit consists of endless chains built up by corner‐linked [BO3]3— triangles. These quasi‐planar zigzag chains of the composition {[(B1)OO(B2)OO]2—} (≡ {[BO2]} run parallel [100]. The La3+ cations exhibit coordination numbers of ten and are coordinated by three Cl and seven O2— anions.  相似文献   

5.
Synthesis, Crystal Structures, and Vibrational Spectra of [(Ph3P)2N]2[(W6Cl )I ] · 2 Et2O · 2 CH2Cl2 and [(Ph3P)2N]2[(W6Cl )(NCS) ] · 2 CH2Cl2 By treatment of [(W6Cl)I]2– with (SCN)2 in dichloromethane at –20 °C the hexaisothiocyanato cluster anion [(W6Cl)(NCS)]2– is formed. X‐ray structure determinations have been performed on single crystals of [(Ph3P)2N]2[(W6Cl)I] · 2 CH2Cl2 · 2 Et2O ( 1 ) (triclinic, space group P1, a = 10.324(5), b = 14.908(3), c = 17.734(8) Å, α = 112.78(2)°, β = 99.13(3)°, γ = 92.02(3)°, Z = 1) and [(Ph3P)2N]2[(W6Cl)(NCS)] · 2 CH2Cl2 ( 2 ) (triclinic, space group P1, a = 11.115(2), b = 14.839(2), c = 17.036(3) Å, α = 104.46(1)°, β = 105.75(2)°, γ = 110.59(1)°, Z = 1). The thiocyanate ligands of 2 are bound exclusively via N atoms with W–N bond lengths of 2.091–2.107 Å, W–N–C angles of 173.1–176.9° and N–C–S angles of 178.1–179.3°. The vibrational spectra exhibit characteristic innerligand vibrations at 2067–2045 (νCN), 879–867 (νCS) and 490–482 (δNCS). Based on the molekular parameters of the X‐ray determination of 1 the vibrational spectra of the corresponding (n‐Bu4N) salt of 1 are assigned by normal coordinate analysis. The valence force constants are fd(WW) = 1.61, fd(WI) = 1.23 and fd(WCl) = 1.10 mdyn/Å.  相似文献   

6.
The Crystal Structure of Perovskites A NiIIMVIO6. II. Sr2NiWO6 The results of an X-ray single crystal study of the perovskite Sr[NiIIWVI](6)O6, ordered in the octahedral sites, are given. While Sr[NiIITeVI](6)O6 crystallizes in a monoclinically deformed structure of the perovskite (elpasolite) type, showing a phase transition to a tetragonal lattice at 675 °K, Sr[NiIIWVI](6)O6 is tetragonal already at 298°K (space group: C; a = b = 5.559 Å; c = 7.918 Å; Z = 2). The Ni? O distances found for the tungsten compound are nearly identical with those of the tellurium perovskite. In contradiction to crystal field theory very different values of the ligand field parameter Δ (ca. 25%) are observed for these two compounds however. Obviously this effect is caused by the rather different kind of bonding within the NiO6 polyhedra in the two compounds. On the basis of the structural results the Ni? O-bonding in the two perovskites is discussed in dependence of the next nearest cationic environment.  相似文献   

7.
Synthesis, Vibrational Spectra, and Crystal Structure of ( n ‐Bu4N)2[(W6Cl )F ] · 2 CH2Cl2 and 19F NMR Spectroscopic Evidence of the Mixed Cluster Anions [(W6Cl )F Cl ]2–, n = 1–6 The reaction of (n‐Bu4N)2[(W6Cl)Cl] with CF3COOH in dichloromethane gives intermediately a mixture of the cluster anions [(W6Cl)(CF3COO)Cl]2–, n = 1–6. By treatment with NH4F the outer sphere coordinated trifluoracetato ligands are easily substituted and the components of the series [(W6Cl)FCl], n = 1–6 are formed and characterized by their distinct 19F NMR chemical shifts. An X‐ray structure determination has been performed on a single crystal of (n‐Bu4N)2[(W6Cl)F] · 2 CH2Cl2 (orthorhombic, space group Pbca, a = 15.628(4), b = 17.656(3), c = 20.687(4) Å, Z = 4). The low temperatur IR (60 K) and Raman (20 K) spectra are assigned by normal coordinate analysis based on the molecular parameters of the X‐ray determination. The valence force constants are fd(WW) = 1.89, fd(WF) = 2.43 and fd(WCl) = 0.93 mdyn/Å.  相似文献   

8.
Magnetic interactions in some oxyfluoroferrites of spinel structure with the formula ZnxMe2?xO4?xFx (M = Fe, Co, Ni) Whereas the ferromagnetic spin arrangement of the B-cations is not modified by the Zn2+?Fe3+ substitution in the ZnFe[Fe2+Fe3+]O4?xFx (0 ≤ x ≤ 0,50) spinel, this same substitution leads to a spin canting in the ZnFe[Co2+Fe3+]O4?xFx and ZnFe[Ni2+Fe3+]O4?xFx (0 ≤ x ≤ 0,80) simples. The difference in the magnetic behaviors with regard to the AB and BB interactions can be explained on the basis of the magnetic exchange theory.  相似文献   

9.
Ba5Ru2O9Cl2 — a New Structure Type of a New Ruthenium(V) Oxidechloride For the first time an alkaline earth-halogenooxo-ruthenate(V) with the formula Ba5Ru2O9Cl2 was prepared and investigated by X-ray single crystal technique. It builds up a new type of structure with an orthorhombic symmetrie (space group D—Pnma, a = 15.310; b = 5.945; c = 14.197 Å). The crystal structure show a threedimensional Ba/O/Cl frame, which contains isolated Ru2O9-double-octahedra. The relations to other structures are discussed.  相似文献   

10.
First Magnetoplumbite Structure Including Rare Earth Ions: Nd2Fe Fe Al9O38 The hitherto unknown compound Nd2Fe15Al9O38 with magnetoplumbite structure was prepared. The symmetry of the isolated red-brown single crystals was determined by X-ray single crystal work (space group D? P63//mmc; a = 568.7; c = 2 223 pm; Z = 2) and the distribution of Fe and Al to the metal positions was identified.  相似文献   

11.
Photoluminescence of Trivalent Rare Earths in Perovskite Stacking Polytypes Ba2La2?x RE MgW2□O12, Ba6Y2?x RE W3□O18, and Sr8SrGd2?xRE W4□O24 Rhombohedral 12 L stacking polytypes Ba2La2?xREMgW2□O12 show with RE3+ = Pr, Sm, Eu, Tb, Dy, Ho, Er, Tm; the 18 L stacking polytypes Ba6Y2?xREW3□O18 and the polymorphic perovskites Sr8SrGd2?xREW4□O24 with RE3+ = Sm, Eu, Dy, Ho, Er visible photoluminescence. The concentration dependence and the influence of the coordination number of the rare earth are reported.  相似文献   

12.
On Ordered Perovskites with Cationic Vacancies. IX. Compounds of the Type Sr2Sr1/4B □1/4WO6?Sr8SrB ?W4O24 (BIII ? La, Pr, Nd, Sm–Tm, Y) The compounds Sr2Sr1/4B□1/4WO6?Sr8SrB?W4O24 belong to the group of perovskites with octahedral cationic vacancies (cation/vacancy ratio (CN 6) ?:1). For the larger BIII ions (La, Pr, Nd, Sm–Dy) different ordering effects are observed. The perovskites with BIII ? Sm, Eu, Gd are polymorphic too (HT modification: higher ordered cubic perovskite (BIII ? Gd: a = 2X8.234 Å); LT modification: hexagonal perovskite stacking polytype (BIII ? Gd: a = 9.954 Å; c = 19.04 Å)). With the smaller BIII ions (Ho, Er, Tm and Y) a cubic, 1:1 ordered perovskite type is observed.  相似文献   

13.
Reactions in the CsCl? TiCl3? Ti system afford CsTiCl3 (CsNiCl3 type, a = 7.3086(7) Å, c = 6.0670(8) Å) and the new phase CsTi2Cl7, the structure of which was determined by single crystal X-ray diffraction means (P2/c, Z = 2, a = 7.0076(4) Å, b = 6.2256(4) Å, c = 12.000(2) Å, β = 92.175(6)°, R/Rw = 0.026/0.035 for 1403 reflections, 2Θ ≤ 60°, MoKα). The structure can be generated by condensation of TiCl6 groups first through cis edges to form TiCl2Cl4/2 ribbons and then by interconnection of these with one chlorine per titanium to give layers, viz., [Ti(Cl)Cl4/2Cl1/2]?. The remaining, singly bonded chlorine projects into the interlayer region and has a Ti? Cl distance 0.208 Å less than the average for the five, 2.466 Å, reflecting significant pi bonding of the chlorine to titanium. Possible interaction of the d orbitals on adjacent titanium(III) atoms is also considered.  相似文献   

14.
Mass Spectrometric Investigation of the Equilibrium POClg + 1/2 O2,g = PO2Clg The oxidation of gaseous POCl at about 1200 K leads to the formation of PO2Cl, which is analogous to the Nitrylchloride NO2Cl. The heat of formation of PO2Cl has been derived from mass spectrometric equilibrium measurements (ΔH(PO2Cl) = ?264.9 kJ/Mol).  相似文献   

15.
On a Novel Alkaline Earth Metal Oxothallate: Sr4Tl2O7 The hitherto unknown compound Sr4Tl2O7 was prepared and investigated by X-ray single crystal methods. Sr4Tl2O7 crystallizes in the tetragonal space group C? P42nm (a = 5.006, c = 18.73 Å). Sr2+ has a trigonal prismatic surrounding whereas Tl3+ shows 2+2 oxygen neighbours. The crystal structure is completely described.  相似文献   

16.
On the chemistry of the elements niobium and tantalum. 84. The niobium and tantalum complexes [Me6X]X · n H2O with Me = Nb, Ta; X1 = Cl, Br; Xa = Cl, Br, J The known and unknown compounds mentioned in the title were prepared. In this group of compounds four different crystal structures (A, B, C, D) occur. Lattice constants are given of the six compounds with structure C which crystallize in the hexagonal system and are isotypic with Ba2[Nb6Cl12]Cl6. Regarding the IR-spectra and the thermal behaviour, possible principles of structure are discussed.  相似文献   

17.
Synthesis, Crystal Structures, and Vibrational Spectra of [(Mo6X)Y]2–; Xi = Cl, Br; Ya = NO3, NO2 By treatment of [(Mo6X)Y]2–; Xi = Ya = Cl, Br with AgNO3 or AgNO2 by strictly exclusion of oxygene in acetone the hexanitrato and hexanitrito cluster anions [(Mo6X)Y]2–, Ya = NO2, NO3 are formed. X-ray structure determinations of (Ph4As)2[(Mo6Cl)(NO3)] · 2 Me2CO ( 1 ) (monoclinic, space group P21/n, a = 12.696(3), b = 21.526(1), c = 14.275(5) Å, β = 115.02(2)°, Z = 2), (n-Bu4N)2[(Mo6Br)(NO3)] · 2 CH2Cl2 ( 2 ) (monoclinic, space group P21/n, a = 14.390(5), b = 11.216(5), c = 21.179(5)Å, β = 96.475(5)°, Z = 2) and (Ph4P)2[(Mo6Cl)(NO2)] (3) (monoclinic, space group P21/n, a = 11.823(5), b = 13.415(5), c = 19.286(5) Å, β = 105.090(5)°, Z = 2) reveal the coordination of the ligands via O atoms with (Mo–O) bond lengths of 2.11–2.13 Å, and (MoON) angles of 122–131°. The vibrational spectra of the nitrato compounds show the typical innerligand vibrations νas(NO2) (∼ 1500), νs(NO2) (∼ 1270) and ν(NO) (∼ 980 cm–1). The stretching vibrations ν(N=O) at 1460–1490 cm–1 and ν(N–O) in the range of 950–1000 cm–1 are characteristic for nitrito ligands coordinated via O atoms.  相似文献   

18.
Preparation and Spectroscopic Characterization of the Cluster Anion [(Mo6Cl )(CF3COO) ]2? On heating of [(Mo6Cl)Cl]2? in dichloromethane with trifluoroacetic acid the new stable cluster anion [(Mo6Cl)(CF3COO)]2? is formed by elimination of HCl. The (Mo6Cl) unit remains unattacked. The 19F nmr spectrum exhibits a downfield shifted singulett as compared to free CF3COO? indicating the equivalence of all trifluoroacetate ligands, which unidentate coordination is deduced from characteristic i. r. frequencies of the carboxyl groups. The most intense i.r. band at 501 cm?1 is assigned to the antisymmetric Mo? Oa vibration, the most intense Raman line at 319 cm?1 to the breathing mode of the Cl cube.  相似文献   

19.
On the Atomic Distribution in Ba2SrIn2O6 with a Contribution to the Existence of the Calciumferrite-Type of Oxoindates (I) Ba2SrIn2O6 and (II) Sr0.93Ba0.07In2O4 were prepared and investigated by single crystal X-ray technique. I crystallizes with tetragonal symmetry, space group D – I4/mmm, a = 4.168; c = 21.290 Å; Z = 2; II belongs to the orthorhombic space group D – Pnma, a = 9.858; b = 3.273; c = 11.520 Å; Z = 4. I shows in respect to the formerly investigated compound BaSr2In2O6 an unexpected statistically distribution of Ba2+ and Sr2+ with the La2SrCu2O6 type. II marks the range of existence of the calciumferrite type within the alkaline earth oxoindates in direction of large radii of M2+ ions.  相似文献   

20.
LiDy2Cl5, an Intermediate of the Metallothermic Reduction of DyCl3 with Lithium LiDy2Cl5 has been obtained via 2 Li + 2 DyCl3 = LiDy2Cl5 + LiCl as black single crystals (700°C, 1 week, sealed tantalum container) and crystallizes monoclinic with a = 1545.6(7), b = 659.2(2), c = 728.7(3) pm, β = 95.79(3)°, Z = 4, C2/c. Octahedra [LiCl6] are connected via common corners to rings [Li4Cl20], these parallel (100) to layers [LiCl4]. Bicapped trigonal prisms [DyCl8] are connected to a three-dimensional network [(DyCl13/3Cl23/3Cl32/4)] ? [Dy2Cl5].  相似文献   

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