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1.
The isotypic nitridosilicates Li4Ca3Si2N6 and Li4Sr3Si2N6 were synthesized by reaction of strontium or calcium with Si(NH)2 and additional excess of Li3N in weld shut tantalum ampoules. The crystal structure, which has been solved by single‐crystal X‐ray diffraction (Li4Sr3Si2N6: C2/m, Z = 2, a = 6.1268(12), b = 9.6866(19), c = 6.2200(12) Å, β = 90.24(3)°, wR2 = 0.0903) is made up from isolated [Si2N6]10– ions and is isotypic to Li4Sr3Ge2N6. The bonding angels and distances within the edge‐sharing [Si2N6]10– double‐tetrahedra are strongly dependent on the lewis acidity of the counterions. This finding is discussed in relation to the compounds Ca5Si2N6 and Ba5Si2N6, which also exhibit isolated [Si2N6]10– ions.  相似文献   

2.
The new nitridogermanate Sr5Ge2N6 was obtained as a coarsely crystalline product by Na‐flux technique employing a reaction of Sr, Na, NaN3 and GeO2 in weld shut tantalum‐tubes at temperatures up to 760 °C. The crystal structure was determined by single‐crystal X‐ray methods: (Sr5Ge2N6, space group C2/c (no. 15), a = 1040.8(2), b = 652.08(13), c = 1356.5(3) pm, β = 100.29(3)°, V = 905.8(3)·106 pm3, Z = 4, 1240 observed reflections, 61 parameters, R1 = 0.031). In the solid, there are edge‐sharing [Ge2N6]10− double tetrahedra surrounded by Sr2+ ions. Sr5Ge2N6 was found to be isotypic with Ca5Si2N6.  相似文献   

3.
Li4Sr2[Cr2N6]: A Hexanitridodichromate(V) The quaternary hexanitridodichromate(V) Li4Sr2[Cr2N6] was obtained by reaction of the metals with flowing nitrogen at 900 °C as black‐shining crystals with a platy habit. The crystal structure was determined by X‐ray single crystal methods (orthorhombic, Pbca; a = 914.0 pm, b = 735.4 pm, c = 1053.6 pm; Z = 4). The compound contains isolated complex anions [Cr2N6]8— consisting of two tetrahedra CrN4 sharing a common edge. The distance Cr—Cr in the complex anion is 249.7 pm. The analysis of the Electron Localization Function (ELF) indicates bonding interactions Cr—Cr. Strontium is in a sixfold (distorted octahedral), Lithium in a distorted tetrahedral ([3+1]) coordination by nitrogen. According to measurements of the magnetic susceptibility the compound is diamagnetic.  相似文献   

4.
Cubic [Ta6Br12(H2O)6][CuBr2X2]·10H2O and triclinic [Ta6Br12(H2O)6]X2·trans‐[Ta6Br12(OH)4(H2O)2]·18H2O (X = Cl, Br, NO3) cocrystallize in aqueous solutions of [Ta6Br12]2+ in the presence of Cu2+ ions. The crystal structures of [Ta6Br12(H2O)6]Cl2·trans‐[Ta6Br12(OH)4(H2O)2]·18H2O ( 1 ) and [Ta6Br12(H2O)6]Br2·trans‐[Ta6Br12(OH)4(H2O)2]·18H2O ( 3 )have been solved in the triclinic space group P&1macr; (No. 2). Crystal data: 1 , a = 9.3264(2) Å, b = 9.8272(2) Å, c = 19.0158(4) Å, α = 80.931(1)?, β = 81.772(2)?, γ = 80.691(1)?; 3 , a = 9.3399(2) Å, b = 9.8796(2) Å, c = 19.0494(4) Å; α = 81.037(1)?, β = 81.808(1)?, γ = 80.736(1)?. 1 and 3 consist of two octahedral differently charged cluster entities, [Ta6Br12]2+ in the [Ta6Br12(H2O)6]2+ cation and [Ta6Br12]4+ in trans‐[Ta6Br12(OH)4(H2O)2]. Average bond distances in the [Ta6Br12(H2O)6]2+ cations: 1 , Ta‐Ta, 2.9243 Å; Ta‐Bri , 2.607 Å; Ta‐O, 2.23 Å; 3 , Ta‐Ta, 2.9162 Å; Ta‐Bri , 2.603 Å; Ta‐O, 2.24 Å. Average bond distances in trans‐[Ta6‐Br12(OH)4(H2O)2]: 1 , Ta‐Ta, 3.0133 Å; Ta‐Bri, 2.586 Å; Ta‐O(OH), 2.14 Å; Ta‐O(H2O), 2.258(9) Å; 3 , Ta‐Ta, 3.0113 Å; Ta‐Bri, 2.580 Å; Ta‐O(OH), 2.11 Å; Ta‐O(H2O), 2.23(1) Å. The crystal packing results in short O···O contacts along the c axes. Under the same experimental conditions, [Ta6Cl12]2+ oxidized to [Ta6Cl12]4+ , whereas [Nb6X12]2+ clusters were not affected by the Cu2+ ion.  相似文献   

5.
Single crystals of Li4(PO2NH)4 · 4 H2O were obtained by dissolving LiOH and H4(PO2NH)4 · 2 H2O in water and subsequent precipitation with acetone and ethanol followed by slow evaporation of the solvents. The structure of Li4(PO2NH)4 · 4 H2O was solved by single‐crystal X‐ray methods ( (No. 2), a = 489.2(2), b = 853.2(2), c = 880.5(2) pm, α = 101.71(3), β = 102.39(3), γ = 94.88(3)°, Z = 1). The structure is composed of LiO4 tetrahedra and (PO2NH)44? ions. The P4N4 rings of the anions exhibit a slightly distorted chair–1 conformation, which is supported by IR data and has been described by torsion angles, displacement asymmetry parameters and puckering parameters. Via Li+ ions and hydrogen bonds, the tetrametaphosphimate anions are connected forming a three‐dimensional network.  相似文献   

6.
Sr2(OLi2Sr4)[CrN4]2, a Nitridochromate(VI)‐Oxide with Oxygen in Tetragonal‐Bipyramidal Coordination by Lithium and Strontium Green gleaming crystals of Sr2(OLi2Sr4)[CrN4]2 were prepared by reaction of Li, Sr and CrN/Cr2N (approximate 1 : 1 mixture) with flowing nitrogen at 900 °C (molar overall composition Li : Sr : Cr = 6 : 1 : ∼3). The oxygen content results from a leak in the gas supply. The crystal structure was determined by single crystal methods (triclinic; P1; a = 615.87(9) pm, b = 682.50(10) pm, c = 754.30(8) pm, α = 82.302(14)°, β = 75.197(10)°, γ = 70.133(13)°; Z = 1) and contains distorted tetragonal bipyramids (OLi2Sr4)8+ and [CrVIN4]6–‐tetrahedra besides Sr2+.  相似文献   

7.
Synthesis and Crystal Structure of the Lithium Strontium Hydride Nitride LiSr2H2N LiSr2H2N was synthesized by the reaction of LiH and Li3N with elemental strontium in sealed tantalum tubes at 650 °C within seven days. This second example of a quaternary hydride nitride crystallizes orthorhombically in space group Pnma (no. 62) with the lattice constants a = 747.14(5) pm, b = 370.28(3) pm and c = 1329.86(9) pm (Z = 4). Its crystal structure contains both kinds of anions H? and N3? in a sixfold distorted octahedral metal cation coordination each. The coordination polyhedra [(H1)Sr5Li]10+, trans‐[(H2)Sr4Li2]9+ and [NSr5Li]8+ are connected via edges and corners to form a three‐dimensional network. Two crystallographically different Sr2+ cations exhibit a sevenfold monocapped trigonal prismatic coordination by H? and N3? with [(Sr1)H5N2]9? and [(Sr2)H4N3]11? polyhedra, wheras Li+ shows a nearly planar fourfold coordinative environment ([LiH3N]5?). Cationic double chains of edge‐shared [NSr5Li]8+ octahedra dominate the structure according to . Running parallel to the [0 1 0] direction, they are bundled like a hexagonal rod‐packing which is interconnected by H? anions within the (0 0 1) plane first and finally even in the third dimension (i. e. along [0 0 1]). Therefore the structure of LiSr2H2N is compared to that one of the closely related quaternary hydride oxide LiLa2HO3.  相似文献   

8.
Synthesis and Crystal Structure of the First Oxonitridoborate — Sr3[B3O3N3] The cyclotri(oxonitridoborate) Sr3[B3O3N3] was synthesized at 1450 °C as coarsely crystalline colourless crystals by the reaction of SrCO3 with poly(boron amide imide) using a radiofrequency furnace. The structure was solved by single‐crystal X‐ray diffractometry (Sr3[B3O3N3], Z = 4, P21/n, a = 663.16(2), b = 786.06(2), c = 1175.90(3) pm, η = 92.393(1)°, R1= 0.0441, wR2 = 0.1075, 1081 independent reflections, 110 refined parameters). Besides Sr2+ there are hitherto unknown cyclic [B3O3N3]6— ions (B—N 143.7(10) — 149.1(9) pm, B—O 140.5(8) — 141.4(8) pm).  相似文献   

9.
The new tetracyanamidoaluminate LiBa2[Al(CN2)4] was prepared by solid state metathesis reaction in a fused copper ampoule from a mixture of BaF2, AlF3, and Li2(CN2) at 550 °C. The crystal structure was solved and refined based on single‐crystal X‐ray diffraction data [P212121, Z = 4, a = 6.843(1) Å, b = 11.828(2) Å, c = 11.857(2) Å]. The compound belongs to the known formula type LiM2[Al(CN2)4] (M = Sr, Eu) containing the homoleptic [Al(CN2)4]5– ion. However, LiBa2[Al(CN2)4] forms a distinct crystal structure, containing a two‐dimensional [(NCN)2/2Li(NCN)2Al(NCN)2/2] network with four‐coordinate Li+ and Al3+ ions. Two crystallographically independent Ba2+ ions are situated in eightfold environment of terminal nitrogen atoms of cyanamide ions.  相似文献   

10.
By the application of cation substitution, a new mixed‐alkali metal diphosphate, K2Li2P2O7, was successfully synthesized through high temperature solution method for the first time. The single‐crystal X‐ray structural analysis shows that it crystallizes in the monoclinic space group C2/c (no. 15), with lattice constants a = 9.814(3) Å, b = 5.5163(15) Å, c = 13.538(4) Å, Z = 4, and β = 110.47(2)°. Its open cage‐like 3[Li2(P2O7)]2– framework is built up from alternating arrangement of Li2O6 and P2O7 dimers that form eight and twelve‐membered‐ring channels along the [010] direction, and the K atoms are entrapped in the larger twelve‐membered‐ring channels. Detailed structure comparisons in the N4P2O7 (N = mixed alkali metals) family are discussed. In addition, the structural validity was verified through the IR spectrum. Thermal analyses and UV/Vis/NIR diffuse reflectance spectrum are also performed on the reported compound.  相似文献   

11.
Synthesis, Crystal Structure and Solid‐State NMR Spectroscopic Investigation of the Oxonitridosilicate BaSi6N8O The phase‐pure oxonitridosilicate BaSi6N8O has been synthesized starting from BaCO3 and silicon diimide Si(NH)2 in a radiofrequency furnace at temperatures below 1630 °C as a coarsely crystalline colorless material. The structure has been determined by single‐crystal X‐ray diffraction analysis (BaSi6N8O, space group Imm2 (no. 44), a = 810.5(2), b = 967.8(2), c = 483.7(1) pm, V = 379.4(2)·106 pm3, Z = 2, R1 = 0.014, 618 independent reflections, 44 parameters). The oxonitridosilicate comprises a three‐dimensional network structure of corner sharing SiN4 and SiON3 tetrahedra with Ba2+ located in the resulting voids. BaSi6N8O is isostructural with the oxonitridoalumosilicate (sialon) Sr2AlxSi12?xN16?xO2+x (x ≈ 2) that previously has been described in the literature. Furthermore, the anionic network of BaSi6N8O derives from that of the homeotypic reduced nitridosilicate SrSi6N8 by a topotactic insertion of oxygen into the Si–Si single bonds. In the 29Si MAS‐NMR spectrum two sharp isotropic signals have been observed at ?54.0 and ?56.3 ppm, respectively. With respect to their observed intensity ratio of 1 : 2.1(1) these two signals have to be attributed to the central atoms of SiON3 and SiN4 tetrahedra, respectively, which is in accordance with the X‐ray crystal structure determination (Si at Wyckoff positions 4d (SiON3) and 8e (SiN4)).  相似文献   

12.
The chain type nitridotantalate LiSr2[TaN3]F was synthesized by reaction of strontium with AlF3, Eu(NH2)2, LiN3 and lithium metal as fluxing agent in weld shut tantalum ampoules. Single crystals were obtained as byproduct from reaction with the ampoule material. The crystal structure (Pbca (no. 61), a = 10.768(2), b = 5.5913(11), c = 15.891(3) Å, Z = 8) was solved on the basis of single‐crystal X‐ray diffraction data. LiSr2[TaN3]F contains infinite chains of vertex sharing TaN4 tetrahedra running along [010]. The structure can be understood as an intercalation of Li+ and F into Sr2TaN3. Lattice energy calculations (MAPLE) and EDX measurements confirmed the electrostatic bonding interactions and the chemical composition.  相似文献   

13.
In 2‐(2‐deoxy‐β‐d ‐erythro‐pentofuranosyl)‐1,2,4‐triazine‐3,5(2H,4H)‐dione (6‐aza‐2′‐deoxy­uridine), C8H11N3O5, (I), the conformation of the glycosylic bond is between anti and high‐anti [χ = −94.0 (3)°], whereas the derivative 2‐(2‐deoxy‐β‐d ‐erythro‐pentofuranosyl)‐N4‐(2‐methoxy­benzoyl)‐1,2,4‐triazine‐3,5(2H,4H)‐dione (N3‐anisoyl‐6‐aza‐2′‐deoxy­uridine), C16H17N3O7, (II), displays a high‐anti conformation [χ = −86.4 (3)°]. The furanosyl moiety in (I) adopts the S‐type sugar pucker (2T3), with P = 188.1 (2)° and τm = 40.3 (2)°, while the sugar pucker in (II) is N (3T4), with P = 36.1 (3)° and τm = 33.5 (2)°. The crystal structures of (I) and (II) are stabilized by inter­molecular N—H⋯O and O—H⋯O inter­actions.  相似文献   

14.
The compounds Li8EN2 with E = Se, Te were obtained in form of orange microcrystalline powders from reactions of Li2E with Li3N. Single crystal growth of Li8SeN2 additionally succeeded from excess lithium. The crystal structures were refined using single‐crystal X‐ray diffraction as well as X‐ray and neutron powder diffraction data (I41md, No. 109, Z = 4, Se: a = 7.048(1) Å, c = 9.995(1) Å, Te: a = 7.217(1) Å, c = 10.284(1) Å). Both compounds crystallize as isotypes with an anionic substructure motif known from cubic Laves phases and lithium distributed over four crystallographic sites in the void space of the anionic framework. Neutron powder diffraction pattern recorded in the temperature range from 3 K to 300 K and X‐ray diffraction patterns using synchrotron radiation taken from 300 K to 1000 K reveal the structural stability of both compounds in the studied temperature range until decomposition. Motional processes of lithium atoms in the title compounds were revealed by temperature dependent NMR spectroscopic investigations. Those are indicated by significant changes of the 7Li NMR signals. Lithium motion starts for Li8SeN2 above 150 K whereas it is already present in Li8TeN2 at this temperature. Quantum mechanical calculations of NMR spectroscopic parameters reveal clearly different environments of the lithium atoms determined by the electric field gradient, which are sensitive to the anisotropy of charge distribution at the nuclear sites. With respect to an increasing coordination number according to 2 + 1, 3, 3 + 1, and 4 for Li(3), Li(4), Li(2), and Li(1), respectively, the values of the electric field gradients decrease. Different environments of lithium predicted by quantum mechanical calculations are confirmed by 7Li NMR frequency sweep experiments at low temperatures.  相似文献   

15.
The formation of ternary nitridometalates from the elements in the case of the systems Li—Cr, V, Mn—N leads to compounds which contain the transition metals in the highest (VV, CrVI) or a comparably high (MnV) oxidation state. In the corresponding calcium and strontium systems, the transition metals show a lower oxidation state (VIII, CrIII, MnIII). Transition metals with intermediate oxidation states (CrV, MnIV) are present in the quaternary (mixed cation) compounds Li4Sr2[CrN6], Li6Ca2[MnN6], and Li6Sr2[MnN6] (R3¯(#148), a = 585.9(3) pm, c = 1908.6(4) pm, Z = 3), as well as in the solid solution series Li6(Ca1—xSrx)2[MnN6].  相似文献   

16.
On the Metal‐rich Lanthanum Nitridoborate Nitride La5(B2N4)N2 La5(B2N4)N2 was synthesized by solid state reactions in fused tantalum containers from Li3(BN2), LaCl3, Li3N and La at 950 °C. The crystal structure refinement on a needle‐shaped single‐crystal yielded the monoclinic space group C2/m, the lattice parameters a = 1259.5(2), b = 368.53(4), c = 909.4(2) pm, β = 106.03(2)°, and R values of R1 = 0.041, wR2 = 0.066 for all independent reflections. The new compound La5(B2N4)N2 introduces the member with x = 2 to the formula type RE3+x(B2N4)Nx (RE = rare earth, x = 0, 1). The structure contains the nitridoborate ion B2N48– that is isoelectronic with the oxalate ion and N3–. Corresponding with (La3+)5(B2N4)8–(N3–)2(e) one additional electron is present.  相似文献   

17.
夏其英  肖鹤鸣  居学海  贡雪东 《中国化学》2004,22(11):1245-1249
Introduction The organoaluminum azide compounds have been widely used in many fields. These compounds are used as the azidating agents,1-3 and the energetic materials which are always used in national defence industry and in space technology, especially to generate thin films of AlN in various chemical vapor deposition (CVD) sys-tems.4-6 Aluminum nitride has useful properties for coatings, especially for optical or optoelectronic devices, acoustic wave devices and electronic microcircuits.7 …  相似文献   

18.
Crystal Structure of Sodium Dihydrogencyamelurate Tetrahydrate Na[H2(C6N7)O3] · 4 H2O Sodium dihydrogencyamelurate‐tetrahydrate Na[H2(C6N7)O3]·4 H2O was obtained by neutralisation of an aqueous solution, previously prepared by hydrolysis of the polymer melon with sodium hydroxide. The crystal structure was solved by single‐crystal X‐ray diffraction ( a = 6.6345(13), b = 8.7107(17), c = 11.632(2) Å, α = 68.96(3), β = 87.57(3), γ = 68.24(3)°, V = 579.5(2) Å3, Z = 2, R1 = 0.0535, 2095 observed reflections, 230 parameters). Both hydrogen atoms of the dihydrogencyamelurate anion are directly bound to nitrogen atoms of the cyameluric nucleus, thus proving the preference of the keto‐tautomere in salts of cyameluric acid in the solid‐state. The compound forms a layer‐like structure with an extensive hydrogen bonding network.  相似文献   

19.
New Sr Compounds with Planar Al‐Si/Ge Anions and a Correction of SrSi‐II and SrGe0.76 Planar anions with considerable pπpπ interactions between heavier group 13 and 14 elements are observed in several alkaline earth trielides and tetrelides. In the intermetallics of the series SrAlxGe2?x (border phases: x = 1: , a = 429.4(3), c = 474.4(3) pm, Z = 1, R1 = 0.0305, SrPtSb type and x = 1.6: P6/mmm, a = 440.4(2), c = 478.2(2) pm, Z = 1, R1 = 0.0125, AlB2 type) graphite analogue planar Al/Ge nets with short Al‐Ge bonds are stacked in identical orientation, showing inter‐layer distances of approx. 475 pm. Starting from the related planar ribbons of condensed six‐membered rings in the known intermetallics (MIV = Si, Ge) a series of new metal‐rich oxides with chain pieces consisting of three, two and finally only one six‐membered ring have been prepared and characterized on the basis of single crystal X‐ray data. The formal fragmentation of the ribbons is achieved by the incorporation of [OSr6] octahedra, chains of which (connected via common corners) exactly fit the distance between the planar anions. The structures of the two compounds (MIV = Si, Ge; formerly erroneously reported as SrSi and SrGe0.76, space group Immm, a = 482.48(5)/484.55(8), b = 1306.5(2)/1342.2(2), c = 1814.0(2)/1857.4(3) pm, Z = 2, R1 = 0.0369/0.0316) contain isolated planar anions [M2Al2M2Al2M2]18? with only one six‐membered ring. In the monoclinic structures of the silicide Sr13[Al6Si8][O] (C2/m, a = 2245.1(4), b = 482.76(5), c = 1720.6(5) pm, β=125.21(2)°, Z = 2, R1 = 0.0579) and the germanide Sr16[Al8Ge10][O] (C2/m, a = 2287.23(14), b = 484.94(3), c = 2065.70(13) pm, β=120.150(4)°, Z = 2, R1 = 0.0730) anions [Si2Al2Si2Al2Si2Al2Si2] and [Ge2M2Ge2M2Ge2M2Ge2M2Ge2] with two and three six‐membered rings are left as fragments of the ribbons in Sr3Al2M2. The puzzling bonding situation in these type of polar intermetallics at the Zintl border is calculated (using the DFT FP‐LAPW approach) for the structures with manageably small unit cells and discussed for the series SrAlM – Sr3Al2M2 – Sr16[Al8M10][O] – Sr13[Al6M8][O] – Sr10[Al4M6][O].  相似文献   

20.
Two novel one‐ and two‐dimensional network structure bismuth(III) complexes with N, N‐di(2‐hydroxylethyl)‐aminodithiocarboxylate, {Bi[S2CN(C2H4OH)2]2[1, 10‐Phen]2(NO3)}·3H2O (1) and (Bi[S2CN(C2H4OH)2]3)2 (2) were synthesized. Their crystal and molecular structures were determined by X‐ray single crystal diffraction analysis. The crystal 1 belongs to monoclinic system with space group C2/c, a=1.6431(7) nm, b=2.4323(10) nm, c= 1.2646(5) nm, β=126. 237(5), Z=4, V=4.076(3) nm3, Dc=1.757 Mg/m3, μ=4.598 mm?1, F(000)=2156, R= 0.0211, wR=0.0369. The structure shows a distorted square antiprism configuration with eight‐coordination for the central Bi atom. The one‐dimensional chain structure was formed by H‐bonding interaction between hydroxyl group of N, N‐di(2‐hydroxylethyl)aminodithiocarboxylate ligands and crystal water. The crystal 2 belongs to monoclinic system with space group p2(1)/c, a= 1.1149(4) nm, b=2.1274(8) nrn, c=2.2107(8) nm, β=98.325(8)°, 2=4, V=5. 188(3) nm3, Dc=1.920 Mg/m3, μ=7.315 mm?1, F(000)=2944, R=0.0565, wR=0.0772. The structure shows a distorted square antiprism configuration with eight‐coordination for the central Bi atoms. The two‐dimensional network structure was formed by H‐bonding interaction between adjacent molecules.  相似文献   

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