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1.
New Ternary Germanides: The Compounds Ln 4Zn5Ge6 ( Ln : Gd, Tm, Lu) Three new ternary germanides were prepared by heating mixtures of the elements. Gd4Zn5Ge6 (a = 4.249(3), b = 18.663(17), c = 15.423(6) Å), Tm4Zn5Ge6 (a = 4.190(1), b = 18.410(5), c = 15.105(5) Å), and Lu4Zn5Ge6 (a = 4.179(1), b = 18.368(4), c = 15.050(3) Å) are isotypic and crystallize in a new structure type (Cmc21; Z = 4), composed of edge‐ and corner‐sharing ZnGe4 tetrahedra. The rare‐earth atoms fill channels of the Zn,Ge network running along the a axis and predominantly have an octahedral coordination of Ge atoms or a pentagonal prismatic environment of Zn and Ge atoms. The ZnGe4 tetrahedra are orientated to each other so that two of six Ge atoms form pairs, while the other ones have no homonuclear contacts. This is in accord with an ionic splitting of the formula: (Ln3+)4(Zn2+)5(Ge3–)2(Ge4–)4. LMTO band structure calculations support the interpretation of bondings derived from interatomic distances. The metallic conductivity of these compounds expected from the electronic band structure was confirmed by measurements of the electrical resistance of Tm4Zn5Ge6.  相似文献   

2.
ACu9X4 ‐ New Compounds with CeNi8, 5Si4, 5 Structure (A: Sr, Ba; X: Si, Ge) The new compounds SrCu9Si4 (a = 8.146(1), c = 11.629(2)Å), BaCu9Si4 (a = 8.198(2), c = 11.735(2)Å), SrCu9Ge4 (a = 8.273(2), c = 11.909(5)Å), and BaCu9Ge4 (a = 8.338(4), c = 12.011(7)Å) are formed by reaction of the elements at 1000° ‐ 1100 °C. They are isotypic (I4/mcm, Z = 4) and crystallize in an ordered variant of the cubic NaZn13 type structure, also built up by the binary phase BaCu13. In the ternary compounds the positions of Cu2 are orderly occupied by copper and silicon and germanium, respectively. This results in a lowering of symmetry and a distortion of the polyhedra. The metallic conductivity of the compounds was confirmed by measurements on BaCu9Si4.  相似文献   

3.
LaPt2Ge2 and EuPt2Ge2 – Revision of the Crystal Structures LaPt2Ge2 was rechecked by single crystal X‐ray methods resulting in space group P21/c (in place of P21) and the lattice constants a = 9.953(3), b = 4.439(1), c = 8.879Å, β = 90.62(4)°, and Z = 4. In contrast to previous reports the cell volume had to be doubled. The same is true for EuPt2Ge2 (a = 9.731(1), b = 4.446(1), c = 8.823(1) Å, β = 91.26(1)°). The crystal structures correspond to a monoclinic variant of the tetragonal CaBe2Ge2 type, whereas the distortion can be described as different rotations of the coordination polyhedra around the La and Eu atoms, respectively. It is most likely that the compounds APt2Ge2 with A = Ca, Y, La‐Dy undergo phase transitions at higher temperatures forming then the undistorted CaBe2Ge2 type, space group P4/nmm. This was confirmed for SmPt2Ge2 (a = 4.292(1), c = 9.980(1) Å; Z = 2) and might also be the case for APt2Ge2 with A = Ca, Nd, Sm, Eu, and Gd.  相似文献   

4.
New Thiophosphates: The Compounds Li6Ln3(PS4)5 (Ln: Y, Gd, Dy, Yb, Lu) and Ag3Y(PS4)2 The new thiophosphates Li6Ln3(PS4)5 (Ln: Y, Gd, Dy, Yb, Lu) were synthesized by heating mixtures of Ln, P, S, and Li2S4 at 900 °C (100 h) and they were investigated by single crystal X‐ray methods. The compounds with Ln = Y (a = 28.390(2), b = 10.068(1), c = 33.715(2) Å, β = 113.85(1)°), Gd (a = 28.327(2), b = 10.074(1), c = 33.822(2) Å, β = 114.297(7)°), Dy (a = 28.124(6), b = 10.003(2), c = 33.486(7) Å, β = 113.89(3)°), Yb (a = 28.178(3), b = 9.977(1), c = 33.392(4) Å, β = 113.65(1)°), and Lu (a = 28.169(6), b = 10.002(2), c = 33.432(7) Å, β = 113.54(3)°) are isotypic and crystallize in a new structure type (C2/c; Z = 12). Main feature are PS4 tetrahedra isolated from each other surrounding the Ln and Li atoms via their S atoms. The coordination number of the five crystallographically independent Ln atoms is eight, but the polyhedra are quite different and they are interlinked to larger units extending in [010]. The environment of the Li atoms is irregular and formed by five to six S atoms. The crystal structure is compared with that of Li9Ln2(PS4)5 (Ln: Nd, Gd). For the synthesis of Ag3Y(PS4)2 (a = 16.874(3), b = 9.190(2), c = 9.312(2) Å, β = 123.17(3)°) a mixture of Y, P, S, and Ag2S was heated to 700 °C (50 h). The thiophosphate crystallizes in a new structure type (C2/c; Z = 4) composed of isolated PS4 tetrahedra. The two crystallographically independent Ag atoms are surrounded by four S atoms in the shape of distorted tetrahedra. The Ag(1)S4 polyhedra are cornershared to strands running along [001], which are linked together via Ag(2)S4 tetrahedra. The environment of the Y atoms is composed of eight S atoms each building distorted square antiprisms. These polyhedra are connected with each other via common edges to a strand running along [001].  相似文献   

5.
The intermetallic phases Tb2NiAl4Ge2 and Ce2NiAl6‐xGe4‐y (x ∼ 0.24, y ∼ 1.34) were synthesized in molten Al at temperatures below 1000 °C. Both compounds adopt the tetragonal space group I4/mmm with cell parameters of a= 4.1346(2) Å c = 19.3437(7) Å for Tb2NiAl4Ge2 and a= 4.1951(9) Å and c = 26.524(7) Å for Ce2NiAl6‐xGe4‐y. The Tb2NiAl4Ge2 structure features NiAl4Ge2 layers separated by a double layer of rare earth ions. The Ce2NiAl6‐xGe4‐y (x ∼ 0.24, y ∼ 1.34) structure also contains the NiAl4Ge2 layers along with a vacancy defect PbO‐type Al2‐xGe2‐y layer, and is related to the Ce2NiGa10 structure type. Ordering of vacancies cause the formation of a 3ax3b superstructure in the crystal as seen by electron diffraction experiments. Tb2NiAl4Ge2 exhibits Curie‐Weiss paramagnetic behavior with an antiferromagnetic transition observed at ∼20 K. Ce2NiAl6‐xGe4‐y shows a much more complex magnetic behavior possibly due to temperature induced variation in the valency of the Ce atoms.  相似文献   

6.
New Rhodium Compounds with the LiCo6P4 Type Structure Five new phosphides and arsenides respectively of the formula ARh6X4 (A: Mg–Sr, Yb; X: P, As) were prepared by heating mixtures of the elements and investigated by means of single crystal X‐ray methods. They are isotypic and crystallize in the LiCo6P4 type structure (P6m2; Z = 1) (lattice constants see ”︁Inhaltsübersicht”︁”︁). The compounds belong to the large family of phosphides and arsenides, which have a metal : non‐metal ratio of about 2 : 1. Their structures are characterized by the environment of phosphorus and arsenic respectively, which is composed of trigonal prisms of metal atoms with additional metal atoms capping the rectangular faces of the prisms.  相似文献   

7.
CuYS2: A Ternary Copper(I) Yttrium(III) Sulfide with Chains {[Cu(S1)3/3(S2)1/1]3–} of cis ‐Edge Connected [CuS4]7– Tetrahedra Pale yellow, lath‐shaped single crystals of the ternary copper(I) yttrium(III) sulfide CuYS2 are obtained by the oxidation of equimolar mixtures of the metals (copper and yttrium) with sulfur in the molar ratio 1 : 1 : 2 within fourteen days at 900 °C in evacuated silica ampoules, while the presence of CsCl as fluxing agent promotes their growth. The crystal structure of CuYS2 (orthorhombic, Pnma; a = 1345.3(1), b = 398.12(4), c = 629.08(6) pm, Z = 4) exhibits chains of cis‐edge linked [CuS4]7– tetrahedra with the composition {[Cu(S1)3/3(S2)1/1]3–} running along [010] which are hexagonally bundled as closest rod packing. Charge equalization and three‐dimensional interconnection of these anionic chains occur via octahedrally coordinated Y3+ cations. These are forming together with the S2– anions a network [Y(S1)3/3(S2)3/3] of vertex‐ and edge‐shared [YS6]9– octahedra with ramsdellite topology. The metall‐sulfur distances of the [CuS4]7– tetrahedra (230 (Cu–S2), 232 (Cu–S1), and 253 pm (Cu–S1′, 2 × )) cover a very broad interval, whilst these (Y–S: 267–280 pm) within the [YS6]9– octahedra range rather closely together.  相似文献   

8.
PrSeTe2, an Ordered Ternary Polychalcogenid with NdTe3 Structure Single crystals of PrSeTe2 have been obtained by reaction of the elements in a LiCl/RbCl flux at 970 K during 7 days. PrSeTe2 crystallizes in space group Cmcm (No. 63), with four formula units per unit cell. The lattice constants are a = 426.1(1) pm, b = 2506.0(5) pm, and c = 426.0(1) pm. The crystal structure is an ordered ternary variant of the NdTe3 type. It consists of a puckered double layer of praseodymium and selenium atoms [PrSe] sand wiched by two square planar layers of tellurium atoms [Te] yielding a stacking —[Te]—[Te]—[PrSe]— along [010]. The Te atoms build regular 44 nets with Te—Te distances of 301, 3(1) pm. DFT calculations propose that this compounds should be metallic mainly due to contributions of the Pr f‐electrons. The band structure shows no significance for a distortion in the [Te]—nets.  相似文献   

9.
Crystal Structures of KNdTe4, RbPrTe4, and RbNdTe4 — Investigations concerning the Thermal Stability of KNdTe4 as well as some Remarks concerning Additional Representatives of the Composition ALnTe4 (A = K, Rb, Cs and Ln = Rare Earth Metal) Of the compounds ALnQ4 (A = Na, K, Rb, Cs; Ln = Lanthanoid; Q = S, Se and Te) the crystal structures of the three new tellurides KNdTe4, RbPrTe4 and RbNdTe4 were determined by X‐ray single‐crystal structure analysis and of the three additional new ones KCeTe4, KPrTe4 and CsNdTe4 by X‐ray powder diffraction experiments. All six new compounds are isotypic with KCeSe4. Characteristic for the crystal structure of the compounds mentioned above are layers built from (Q2)2— dumbbells in form of 4.32.4.3 nets with embedded cations A+ and Ln3+ between them, which are coordinated eightfold in form of square‐shaped antiprisms by Q ions. The distances Te‐Te within the dumbbells were found to be 277.8(2) pm for all investigated tellurides. By combination of X‐ray diffraction and DTA measurements it was shown that the compound KNdTe4 is metastable at ambient temperature with a limited existence range between the temperatures 260 and 498 °C.  相似文献   

10.
Ruby‐red, bead‐shaped single crystals of C‐type La2Se3 (a = 905.21(6) pm), Pr2Se3 (a = 891.17(6) pm), and Gd2Se3 (a = 872.56(5) pm) are obtained by oxidation of the respective rare‐earth metal (M = La, Pr and Gd) with selenium (molar ratio 2 : 3) in evacuated silica tubes at 750 °C in the presence of fluxing CsCl within seven days. Their crystal structure belongs to a cation‐deficient Th3P4‐type variant (cubic, I 4 3d) according to M2.6670.333Se4 (Z = 4) or M2Se3 (Z = 5.333) offering coordination numbers of eight (Se2– arranged as trigonal dodecahedra) to the M3+ cations. In spite of the high Cs+ activity in molten CsCl, no cesium incorporation into the M5.3330.667Se8‐frame structure (e. g. as CsM5Se8 with Z = 2) could be achieved, judged from both results of electron beam X‐ray microanalyses and refined occupation factors of the metal position very close to x = 8/9 for M3xSe4.  相似文献   

11.
Crystal Structures of CaBe2Ge2 and CeMg2Si2 analogous Units: The Phosphides LnPt2P2?x (Ln: La, Sm) Single crystals of LaPt2P1.44 (a = 4.174(1), c = 19.212(5) Å) were grown by reaction of vaporous phosphorus with LaPt2 at 1050 °C during two weeks, whereas SmPt2P1.50 (a = 4.131(1), c = 19.086(4) Å) was synthesized by heating mixtures of the elements at 900 and 1100 °C (60 h) and annealing at 1050 °C (300 h). Both phosphides were investigated by single crystal X‐ray methods. Their crystal structures (I4/mmm; Z = 4) consist of CaBe2Ge2 and CeMg2Si2 analogous units alternating with each other along [001]. The positions of the P1 atoms are occupied incompletely causing the deviation to the 1:2:2 stoichiometry. Another compounds LnPt2P2?x were studied by X‐ray powder diffraction resulting in the following lattice constants: a = 4.150(1), c = 19.132(5) Å for CePt2P2–x, a = 4.137(1), c = 19.085(4) Å for PrPt2P2?x, and a = 4.127(1), c = 19.040(2) Å for NdPt2P2?x.  相似文献   

12.
Syntheses and Crystal Structures of New Alkali Metal Rare‐Earth Tellurides of the Compositions KLnTe2 (Ln = La, Pr, Nd, Gd), RbLnTe2 (Ln = Ce, Nd) and CsLnTe2 (Ln = Nd) Of the compounds ALnQ2 (A = Na, K, Rb, Cs; Ln = rare earth‐metal; Q = S, Se, Te) the crystal structures of the new tellurides KLaTe2, KPrTe2, KNdTe2, KGdTe2, RbCeTe2, RbNdTe2, and CsNdTe2 were determined by single‐crystal X‐ray analyses. They all crystallize in the α‐NaFeO2 type with space group R3¯m and three formula units in the unit cell. The lattice parameters are: KLaTe2: a = 466.63(3) pm, c = 2441.1(3) pm; KPrTe2: a = 459.73(2) pm, c = 2439.8(1) pm; KNdTe2: a = 457.83(3) pm, c = 2443.9(2) pm; KGdTe2: a = 449.71(2) pm, c = 2443.3(1) pm; RbCeTe2: a = 465.18(2) pm, c = 2533.6(2) pm; RbNdTe2: a = 459.80(3) pm, c = 2536.5(2) pm, and CsNdTe2: a = 461.42(3) pm, c = 2553.9(3) pm. Characteristics of the α‐NaFeO2 structure type as an ordered substitutional variant of the rock‐salt (NaCl) type are layers of corner‐sharing [(A+/Ln3+)(Te2—)6] octahedra with a layerwise alternating occupation by the cations A+ and Ln3+.  相似文献   

13.
Synthesis and Crystal Structures of Ln 2Al3Si2 and Ln 2AlSi2 ( Ln : Y, Tb–Lu) Eight new ternary aluminium silicides were prepared by heating mixtures of the elements and investigated by means of single‐crystal X‐ray methods. Tb2Al3Si2 (a = 10.197(2), b = 4.045(1), c = 6.614(2) Å, β = 101.11(2)°) and Dy2Al3Si2 (a = 10.144(6), b = 4.028(3), c = 6.580(6) Å, β = 101.04(6)°) crystallize in the Y2Al3Si2 type structure, which contains wavy layers of Al and Si atoms linked together by additional Al atoms and linear Si–Al–Si bonds. Through this there are channels along [010], which are filled by Tb and Dy atoms respectively. The silicides Ln2AlSi2 with Ln = Y (a = 8.663(2), b = 5.748(1), c = 4.050(1) Å), Ho (a = 8.578(2), b = 5.732(1), c = 4.022(1) Å), Er (a = 8.529(2), b = 5.719(2), c = 4.011(1) Å), Tm (a = 8.454(5), b = 5.737(2), c = 3.984(2) Å) and Lu (a = 8.416(2), b = 5.662(2), c = 4.001(1) Å) crystallize in the W2CoB2 type structure (Immm; Z = 2), whereas the structure of Yb2AlSi2 (a = 6.765(2), c = 4.226(1) Å; P4/mbm; Z = 2) corresponds to a ternary variant of the U3Si2 type structure. In all compounds the Si atoms are coordinated by trigonal prisms of metal atoms, which are connected by common faces so that Si2 pairs (dSi–Si: 2.37–2.42 Å) are formed.  相似文献   

14.
Reactions of PtCl2(cod) (cod = cycloocta‐1,5‐diene) with 2,4,6‐trifluoro‐ and 2,3,4,5‐tetrafluoro‐phenyllithium in diethyl ether gives Pt(C6H2F3‐2,4,6)2(cod) ( 1 ) (monoclinic, P21/n, Z = 4, a = 7.141(1), b = 15.002(2), c = 17.071(3) Å, β = 91.37(2)°) and Pt(C6HF4‐2,3,4,5)2(cod) ( 2 ) (triclinic, P 1, Z = 2, a = 10.150(2), b = 10.762(2), c = 10.812(2) Å, α = 63.606(3), β = 63.327(3), γ = 76.496(3)°) respectively, which have two ipso carbon atoms and two double bond midpoint centres in a square planar arrangement, and aromatic rings angled near perpendicular to the coordination plane.  相似文献   

15.
The synthesis, structure determination and calculated electronic structure of the new phase, Gd2AlGe2, are reported. The compound crystallizes in a new structure type with space group C2/c, a = 10.126(2) Å, b = 5.6837(12) Å, c = 7.7683(16) Å, and β = 104.729(3)s. Tight‐binding linear‐muffin‐tin orbital (TB‐LMTO‐ASA) calculations show a distinct minimum in the total density of states for this structure at 18 valence electrons per formula unit (Gd2AlGe2 has 17 valence electrons in its formula unit), which arises from polar covalent bonding within the three‐dimensional [AlGe2] net, Gd‐Ge interactions and three‐center, two‐electron bonding between Al and Gd. The structure is a new stacking variant of the W2CoB2 structure type, which is observed for numerous ternary rare‐earth silicides and germanides.  相似文献   

16.
New ternary phosphides Ln25Ni49P33 (Ln = Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er) have been synthesized by arc melting of pure components. Crystal structure has been determined for Sm25Ni49P33 using X‐ray powder diffraction data and the Rietvelt method: P6m2, a = 22.096(4), c = 3.8734(9) Å, R = 0.096. Crystal structure of Sm25Ni49P33 is of a new type and belongs to large family of ternary compounds with trigonal‐prismatic coordination of the smallest size atoms and metal to nonmetal ratio equal or close to 2 : 1. It is a member of homologous subseries of the compounds with unit cell contents described by general chemical formula R M X . Lattice parameters of the isotypic compounds Ln25Ni49P33 have been refined using X‐ray powder diffraction data.  相似文献   

17.
Ligand exchange reactions of cis‐PtCl2(PPh3)2 and [NMe4]SCF3 in different ratios were studied. Depending on the stoichiometry reactions proceeded with formation of products expected for the chosen ratio, i. e. cis‐Pt(SCF3)Cl(PPh3)2, cis‐Pt(SCF3)2(PPh3)2, and [NMe4][Pt(SCF3)3(PPh3)]. Starting from cis‐PtCl2(MeCN)2 and [NMe4]SCF3 and adding PPh3 after substitution, product mixtures were dominated by the corresponding trans‐isomers. Results of the single crystal structure analyses of cis‐Pt(SCF3)2(PPh3)2 and trans‐Pt(SCF3)Cl(PPh3)2 are discussed.  相似文献   

18.
Caesiumchloropalladate(II)‐hydrates – Two New Compounds with Condensed [Pd2Cl6] Groups We were able to synthesize two caesiumchloropalladate(II)‐hydrates in the CsCl/PdCl2/H2O system by hydrothermal methods. Both compounds show combination of monomeric and dimeric Pd–Cl groups. We characterized the crystal structures by single‐crystal X‐ray diffraction. Cs6Pd5Cl16 · 2 H2O ( I ) crystallizes triclinic in space group type P1 (Nr. 2) with a = 8.972(1) Å, b = 11.359(1) Å, c = 18.168(1) Å, α = 83.61(1)°, β = 76.98(1)°, γ = 76.39(1)° and Z = 2, Cs12Pd9Cl30 · 2 H2O ( II ) monoclinic, space group type C2/m (No. 12) with a = 19.952(1) Å, b = 14.428(1) Å, c = 14.411(1) Å, β = 125.29(1)°, and Z = 2.  相似文献   

19.
Coordination Chemistry of P‐rich Phosphanes and Silylphosphanes. XX Formation and Structure of [{η2tBu2P–P}Pt(PHtBu2)(PPh3)] [{η2tBu2P1–P2}Pt(P3Ph3)(P4Ph3)] ( 2 ) reacts with tBu2PH exchanging only the P3Ph3 group to give [{η2tBu2P1–P2}Pt(P3HtBu2)(P4Ph3)] ( 1 ). The crystal stucture determination of 1 together with its 31P{1H} NMR data allow for an unequivocal assignment of the coupling constants in related Pt complexes. 1 crystallizes in the triclinic space group P1 (no. 2) with a = 1030.33(15), b = 1244.46(19), c = 1604.1(3) pm, α = 86.565(17)°, β = 80.344(18)°, γ = 74.729(17)°.  相似文献   

20.
Synthesis, Crystal Structures, and Vibrational Spectra of [Pt(N3)6]2– and [Pt(N3)Cl5]2–, 195Pt and 15N NMR Spectra of [Pt(N3)nCl6–n]2– and [Pt(15NN2)n(N215N)6–n]2–, n = 0–6 By ligand exchange of [PtCl6]2– with sodium azide mixed complexes of the series [Pt(N3)nCl6–n]2– and with 15N‐labelled sodium azide (Na15NN2) mixtures of the isotopomeres [Pt(15NN2)n(N215N)6–n]2–, n = 0–6 and the pair [Pt(15NN2)Cl5]2–/[Pt(N215N)Cl5]2– are formed. X‐ray structure determinations on single crystals of (Ph4P)2[Pt(N3)6] ( 1 ) (triclinic, space group P1, a = 10.175(1), b = 10.516(1), c = 12.380(2) Å, α = 87.822(9), β = 73.822(9), γ = 67.987(8)°, Z = 1) and (Ph4As)2[Pt(N3)Cl5] · HCON(CH3)2 ( 2 ) (triclinic, space group P1, a = 10.068(2), b = 11.001(2), c = 23.658(5) Å, α = 101.196(14), β = 93.977(15), γ = 101.484(13)°, Z = 2) have been performed. The bond lengths are Pt–N = 2.088 ( 1 ), 2.105 ( 2 ) and Pt–Cl = 2.318 Å ( 2 ). The approximate linear azido ligands with Nα–Nβ–Nγ‐angles = 173.5–174.6° are bonded with Pt–Nα–Nβ‐angles = 116.4–121.0°. In the vibrational spectra the PtCl stretching vibrations of (n‐Bu4N)2[Pt(N3)Cl5] are observed at 318–345, the PtN stretching modes of (n‐Bu4N)2[Pt(N3)6] at 401–428 and of (n‐Bu4N)2[Pt(N3)Cl5] at 408–413 cm–1. The mixtures (n‐Bu4N)2[Pt(15NN2)n(N215N)6–n], n = 0–6 and (n‐Bu4N)2[Pt(15NN2)Cl5]/(n‐Bu4N)2[Pt(N215N)Cl5] exhibit 15N‐isotopic shifts up to 20 cm–1. Based on the molecular parameters of the X‐ray determinations the vibrational spectra are assigned by normal coordinate analysis. The average valence force constants are fd(PtCl) = 1.93, fd(PtNα) = 2.38 and fd(NαNβ, NβNγ) = 12.39 mdyn/Å. In the 195Pt NMR spectrum of [Pt(N3)nCl6–n]2–, n = 0–6 downfield shifts with the increasing number of azido ligands are observed in the range 4766–5067 ppm. The 15N NMR spectrum of (n‐Bu4N)2[Pt(15NN2)n(N215N)6–n], n = 0–6 exhibits by 15N–195Pt coupling a pseudotriplett at –307.5 ppm. Due to the isotopomeres n = 0–5 for terminal 15N six well‐resolved signals with distances of 0.03 ppm are observed in the low field region at –201 to –199 ppm.  相似文献   

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