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1.
Two new isostructural cobalt selenite halides Co5(SeO3)4Cl2 and Co5(SeO3)4Br2 have been synthesized. They crystallize in the triclinic system space group P−1 with the following lattice parameters for Co5(SeO3)4Cl2: a=6.4935(8) Å, b=7.7288(8) Å, c=7.7443(10) Å, α=66.051(11)°, β=73.610(11)°, γ=81.268(9)°, and Z=1. The crystal structures were solved from single-crystal X-ray data, R1=3.73 and 4.03 for Co5(SeO3)4Cl2 and Co5(SeO3)4Br2, respectively. The new compounds are isostructural to Ni5(SeO3)4Br2.Magnetic susceptibility measurements on oriented single-crystalline samples show anisotropic response in a broad temperature range. The anisotropic susceptibility is quantitatively interpreted within the zero-field splitting schemes for Co2+ and Ni2+ ions. Sharp low-temperature susceptibility features, at TN=18 and 20 K for Co5(SeO3)4Cl2 and Co5(SeO3)4Br2, respectively, are ascribed to antiferromagnetic ordering in a minority magnetic subsystem. In isostructural Ni5(SeO3)4Br2 magnetically ordered subsystem represents a majority fraction (TN=46 K). Nevertheless, anisotropic susceptibility of Ni5(SeO3)4Br2 is dominated at low temperatures by a minority fraction, subject to single-ion anisotropy effects and increasing population of Sz=0 (singlet) ground state of octahedrally coordinated Ni2+.  相似文献   

2.
Ag4(Mo2O5)(SeO4)2(SeO3) has been synthesized by reacting AgNO3, MoO3, and selenic acid under mild hydrothermal conditions. The structure of this compound consists of cis-MoO22+ molybdenyl units that are bridged to neighboring molybdenyl moieties by selenate anions and by a bridging oxo anion. These dimeric units are joined by selenite anions to yield zigzag one-dimensional chains that extended down the c-axis. Individual chains are polar with the C2 distortion of the Mo(VI) octahedra aligning on one side of each chain. However, the overall structure is centrosymmetric because neighboring chains have opposite alignment of the C2 distortion. Upon heating Ag4(Mo2O5)(SeO4)2(SeO3) looses SeO2 in two distinct steps to yield Ag2MoO4. Crystallographic data: (193 K; MoKα, λ=0.71073 Å): orthorhombic, space group Pbcm, a=5.6557(3), b=15.8904(7), c=15.7938(7) Å, V=1419.41(12), Z=4, R(F)=2.72% for 121 parameters with 1829 reflections with I>2σ(I). Ag2(MoO3)3SeO3 was synthesized by reacting AgNO3 with MoO3, SeO2, and HF under hydrothermal conditions. The structure of Ag2(MoO3)3SeO3 consists of three crystallographically unique Mo(VI) centers that are in 2+2+2 coordination environments with two long, two intermediate, and two short bonds. These MoO6 units are connected to form a molybdenyl ribbon that extends along the c-axis. These ribbons are further connected together through tridentate selenite anions to form two-dimensional layers in the [bc] plane. Crystallographic data: (193 K; MoKα, λ=0.71073 Å): monoclinic, space group P21/n, a=7.7034(5), b=11.1485(8), c=12.7500(9) Å, β=105.018(1) V=1002.7(2), Z=4, R(F)=3.45% for 164 parameters with 2454 reflections with I>2σ(I). Ag2(MoO3)3SeO3 decomposes to Ag2Mo3O10 on heating above 550 °C.  相似文献   

3.
Two new barium zinc selenite and tellurite, namely, BaZn(SeO3)2 and BaZn(TeO3)Cl2, have been synthesized by the solid state reaction. The structure of BaZn(SeO3)2 features double chains of [Zn(SeO3)2]2− anions composed of four- and eight-member rings which are alternatively along a-axis. The double chains of [Zn2(TeO3)2Cl3]3− anions in BaZn(TeO3)Cl2 are formed by Zn3Te3 rings in which each tellurite group connects with three ZnO3Cl tetrahedra. BaZn(SeO3)2 and BaZn(TeO3)Cl2 are wide bandgap semiconductors based on optical diffuse reflectance spectrum measurements.  相似文献   

4.
The new nickel selenite chloride, Ni5(SeO3)4Cl2, was obtained by high-temperature solid state reaction of NiCl2, Ni2O3 and SeO2 in a 1:2:4 molar ratio at 700 °C in an evacuated quartz tube. Its structure was established by single-crystal X-ray diffraction. Ni5(SeO3)4Cl2 crystallizes in the triclinic system, space group P-1 (No. 2) with cell parameters of a=8.076(2), b=9.288(2), c=9.376(2) Å, α=101.97(3), β=105.60(3), γ=91.83(3)° and Z=2. All nickel(II) ions in Ni5(SeO3)4Cl2 are octahedrally coordinated by selenite oxygens or/and chloride anions (([Ni(1)O5Cl], [Ni(2)O4Cl2], [Ni(3)O5Cl], [Ni(4)O6] and [Ni(5)O4Cl]). The structure of the title compound features a condensed three-dimensional (3D) network built by Ni(II) ions interconnected by SeO32− anions as well as Cl anions. Magnetic property measurements show strong antiferromagnetic interaction between nickel(II) ions.  相似文献   

5.
The reaction between PuO2 and SeO2 under mild hydrothermal conditions results in the formation of Pu(SeO3)2 as brick-red prisms. This compound adopts the Ce(SeO3)2 structure type, and consists of one-dimensional chains of edge-sharing [PuO8] distorted bicapped trigonal prisms linked by [SeO3] units into a three-dimensional network. Crystallographic data: Pu(SeO3)2, monoclinic, space group P21/n, a=6.960(1) Å, b=10.547(2) Å, c=7.245(1) Å, β=106.880(9)°, V=508.98(17) Å3, Z=4 (T=193 K), R(F)=2.92% for 83 parameters with 1140 reflections with I>2σ(I). Magnetic susceptibility data for Pu(SeO3)2 are linear from 35 to 320 K and yield an effective moment of 2.71(5) μB and a Weiss constant of −500(5) K.  相似文献   

6.
Two new alkaline-earth Nd selenite chlorides MNd10(SeO3)12Cl8 (M=Ca, Sr) were obtained using crystal growth from alkaline-earth chloride melts in quartz tubes. These new compounds crystallize in the orthorhombic system in space group C cca (#68). The compounds were studied by energy dispersive X-ray spectroscopy (EDX) and X-ray diffraction. It was shown that both compounds adopt the same structure type, constructed by complex [M11(SeO3)12]8+ slabs separated by chloride anion layers perpendicular to the longest cell parameter. The SeO3 groups show a pyramidal shape and may be described as SeO3E tetrahedra. Such SeO3 groups decorate the Nd-O skeletons forming the [M11(SeO3)12]8+ slabs.  相似文献   

7.
Three new hydrated scandium selenites have been hydrothermally synthesized as single crystals and structurally and physically characterized. Sc2(SeO3)3·H2O crystallizes as a new structure type containing novel ScO7 pentagonal bipyramidal and ScO6+1 capped octahedral coordination polyhedra. Sc2(SeO3)3·3H2O contains typical ScO6 octahedra and is isostructural with its M2(SeO3)3·3H2O (M=Al, Cr, Fe, Ga) congeners. CsSc3(SeO3)4(HSeO3)2·2H2O contains near-regular ScO6 octahedra and has essentially the same structure as its indium-containing analogue. All three phases contain the expected pyramidal [SeO3]2- selenite groups. Crystal data: Sc2(SeO3)3·3H2O, Mr=524.85, trigonal, R3c (No. 161), , , , Z=6, R(F)=0.018, wR(F2)=0.036; Sc2(SeO3)3·H2O, Mr=488.82, orthorhombic, P212121 (No. 19), , , , , Z=4, R(F)=0.051, wR(F2)=0.086; CsSc3(SeO3)4(HSeO3)2·2H2O, Mr=1067.60, orthorhombic, Pnma (No. 62), , , , , Z=4, R(F)=0.035, wR(F2)=0.070.  相似文献   

8.
9.
The hydrothermal syntheses, single crystal structures, and some properties of Ba2MnIIMn2III(SeO3)6 and PbFe2(SeO3)4 are reported. These related phases contain three-dimensional frameworks of vertex (FeO6) and vertex/edge linked (MnO6) octahedra and SeO3 pyramids. In each case, the MO6/SeO3 framework encloses two types of 8 ring channels, one of which encapsulates the extra-framework cations and one of which provides space for the SeIV lone pairs. Crystal data: Ba2Mn3(SeO3)6, Mr=1201.22, monoclinic, P21/c (No. 14), a=5.4717 (3) Å, b=9.0636 (4) Å, c=17.6586 (9) Å, β=94.519 (1)°, V=873.03 (8) Å3, Z=2, R(F)=0.031, wR(F2)=0.070; PbFe2(SeO3)4, Mr=826.73, triclinic, (No. 2), a=5.2318 (5) Å, b=6.7925 (6) Å, c=7.6445 (7) Å, α=94.300 (2)°, β=90.613 (2)°, γ=95.224 (2)°, V=269.73 (4) Å3, Z=1, R(F)=0.051, wR(F2)=0.131.  相似文献   

10.
The crystal structures of four hydrothermally synthesized alkaline earth-copper-selenites were determined: BaCu(SeO3)2-I [a = 5.247(1), B = 13.353(2), C = 8.981(1) Å, space group Pnm21, Z = 4, Rw = 0.024 for 1270 reflections], BaCu(SeO3)2-II [a = 5.256(1), B = 13.231(2), C = 8.933(1) Å, β = 90.19(1)°, space group P21/c, Z = 4, Rw = 0.046 for 2238 reflections], BaCu(SeO3)2-III [a = 8.031(1), B = 5.185(1), C = 15.823(2) Å, β = 90.83(1)°, space group C2/c, Z = 4, Rw = 0.038 for 1866 reflections], and SrCu(SeO3)2 [a = 7.929(1), B = 5.132(1), C = 14.997(2) Å, β = 90.53(1)°, space group C2/c, Z = 4, Rw = 0.028 for 1414 reflections; isotypic with BaCu(SeO3)2-III].BaCu(SeO3)2-I and -II contain Cu(SeO3)2 sheets lying parallel to (100) formed by CuO4 “squares” and selenite groups. These sheets are topologically different: in BaCu(SeO3)2-I they are formed by the connection of Cu2(SeO3) and Cu6(SeO3)4 rings while in BaCu(SeO3)2-II they are formed by Cu2(SeO3)2 and Cu6(SeO3)6 rings. The Cu(SeO3)2 sheets are rugged in BaCu(SeO3)2-I and they are slightly waved in BaCu(SeO3)2-II. In both compounds they are connected to each other by a fifth Cu---O bond and by the Ba atoms. In BaCu(SeO3)2-III and in its isotypic Sr analog the CuO4 “squares” and the selenite groups form parallel chains [010], which are connected by the alkaline earth atoms.  相似文献   

11.
Two novel vanadium selenites {[VO(OH)(H2O)](SeO3)}4·2H2O 1 and (H3NCH2CH2NH3)[(VO)(SeO3)2] 2 were synthesized by hydrothermal method and their crystal structures were determined by single-crystal X-ray diffraction. It is characterized by inductively coupled plasma (ICP), thermogravimetric (TG) and elemental analyses. Compound 1 crystallizes in the monoclinic system, space group C2/c, a=21.2250(11) Å, b=12.6309(6) Å, c=17.0249(10) Å, β=96.830(3)°, V=4531.8(4) Å3 and Z=8, R1 [I>2σ(I)]=0.0344, wR2 [I>2σ(I)]=0.119; Compound 2 crystallizes in the monoclinic system, space group P21/c, a=9.6389(4) Å, b=6.9922(3) Å, c=15.0324(5) Å, β=102.297(2)°, V=989.90(7) Å3 and Z=4, R1 [I>2σ(I)]=0.0452, wR2 [I>2σ(I)]=0.117. {[VO(OH)(H2O)](SeO3)}4·2H2O has a 1D structure constructed from the {[VO(OH)(H2O)](SeO3)} chains. (H3NCH2CH2NH3)[(VO)(SeO3)2] has a layered structure composed of alternating VO5 and SeO3 units with protonated ethylenediamine as interlayer guest.  相似文献   

12.
将过渡金属配合物阳离子([M(DETA)2]n+(M=Cu2+,Ni2+,Co3+;DETA=Diethylenetriamine,二乙烯三胺)作为客体插入层状MnPS3层间得到了相应的3个夹层化合物。通过X-射线粉末衍射、元素分析和红外光谱对夹层化合物的结构进行了表征。结果表明,与主体MnPS3 0.65 nm的层间距相比较,夹层化合物(Mn0.88PS3[Cu(DETA)2]0.12)的层间距扩大了0.32 nm,由此推测客体[Cu(DETA)2]2+在层间以平面四方的配位形式存在,而另2个夹层化合物(Mn0.79PS3[Ni(DETA)2]0.21和Mn0.74PS3[Co(DETA)2]0.17)的层间距扩大了0.48 nm,说明客体[(M(DETA)2]n+,M=Co3+,Ni2+) 在主体层间以八面体配位形式存在。磁性测试结果表明过渡金属离子[(M(DETA)2]n+(M=Cu2+,Co3+)的插入能引起主体MnPS3的磁性在35~40 K发生由顺磁向亚铁磁性的转变并表现自发磁化,而客体[Ni(DETA)2]2+却使夹层化合物的反铁磁相互作用增强,抑制了自发磁化的发生。  相似文献   

13.
14.
The synthesis, structure, and basic magnetic properties of Na2Co2TeO6 and Na3Co2SbO6 are reported. The crystal structures were determined by neutron powder diffraction. Na2Co2TeO6 has a two-layer hexagonal structure (space group P6322) while Na3Co2SbO6 has a single-layer monoclinic structure (space group C2/m). The Co, Te, and Sb ions are in octahedral coordination, and the edge sharing octahedra form planes interleaved by sodium ions. Both compounds have full ordering of the Co2+ and Te6+/Sb5+ ions in the ab plane such that the Co2+ ions form a honeycomb array. The stacking of the honeycomb arrays differ in the two compounds. Both Na2Co2TeO6 and Na3Co2SbO6 display magnetic ordering at low temperatures, with what appears to be a spin-flop transition found in Na3Co2SbO6.  相似文献   

15.
Two compounds, [Co(bpy)2(NiL)](ClO4)2 (1)and {[Co(phen)3](NiL)}(ClO4)2 (2), have been synthesized: (H2L=2,3-dioxo-5,6,14,15-dibenzo-1,4,8,12-tetraazacylotetradeca-7,12-diene, bpy=2,2-bypyridine and phen = 1,10-phenanthroline). Compound (1) contains a discrete binuclear [Co(bpy)2(NiL)]2+ cation, while compound (2) is composed of [Co(phen)3]2+ cations and NiL neutral fragments. The magnetic properties of compound (1) have been dealt with by isotropic one-ion approximation of the CoII ion with a spin--orbit coupling in an Oh symmetry environment. The electronic spectra of these two compounds have also been discussed.  相似文献   

16.
Single crystals of (CN3H6)2[(UO2)2(C2O4)(SeO3)2] were synthesized and studied by IR spectroscopy and X-ray diffraction. The compound crystallizes in the triclinic system with the unit cell parameters a = 7.1169(12) ?, b = 7.4874(10) ?, c = 8.9748(14) ?, α = 88.243(6)°, β = 74.546(6)°, γ = 81.445(6)°, space group P[`1]P\bar 1, Z = 1, R = 0.0304. The main structural units of the crystals are layers of the [(UO2)2(C2O4)(SeO3)2]2− composition; the layers belong to the crystal chemical group A 2 K 02 T 23 (A = UO22+ K 02 = C2O42−, T 3 = SeO3) of uranyl complexes. Uranium-containing complex groups are linked by electrostatic interactions and a network of hydrogen bonds with CN3H6+ guanidinium ions to form a three-dimensional framework.  相似文献   

17.
Layered LiNi0.4Co0.2Mn0.4O2, Li[Li0.182Ni0.182Co0.091Mn0.545]O2, Li[Li1/3Mn2/3]O2 powder materials were prepared by rheological phase method. XRD characterization shows that these samples all have analogous structure to LiCoO2. Li[Li0.182Ni0.182Co0.091Mn0.545]O2 can be considered to be the solid solution of LiNi0.4Co0.2Mn0.4O2 and Li[Li1/3Mn2/3]O2. Detailed information from XRD, ex situ XPS measurement and electrochemical analysis of these three materials reveals the origin of the irreversible plateau (4.5 V) of Li[Li0.182Ni0.182Co0.091Mn0.545]O2 electrode. The irreversible oxidation reaction occurred in the first charging above 4.5 V is ascribed to the contribution of Li[Li1/3Mn2/3]O2 component, which maybe extract Li+ from the transition layer in Li[Li1/3Mn2/3]O2 or Li[Li0.182Ni0.182Co0.091Mn0.545]O2 through oxygen release. This step also activates Mn4+ of Li[Li1/3Mn2/3]O2 or Li[Li0.182Ni0.182Co0.091Mn0.545]O2, it can be reversibly reduced/oxidized between Mn4+ and Mn3+ in the subsequent cycles.  相似文献   

18.
All the steps of the proposed technique, from the synthesis of single-source precursors to the preparation of CoPd and CoPt nanoalloys, are described. The double complex salts (DCS) [M(NH3)4][Co(C2O4)2(H2O)2]·2H2O (M = Pd, Pt), which were synthesized by mixing solutions containing [M(NH3)4]2+ cations and [Co(C2O4)2(H2O)2]2− anions, have been used as precursors. The salts obtained were characterized by IR spectroscopy, thermal analysis, XRD and single crystal X-ray diffraction. The prepared compounds crystallize in the monoclinic (space group I2/m, M = Pd) and orthorhombic (space group I222, M = Pt) crystal systems. Thermal decomposition of the salts in helium or hydrogen atmosphere at 200-600 °C results in the formation of nanoalloys powders (random solid solution Co0.50Pd0.50 and chemically ordered CoPt). The size of the bimetallic particles varied from 5 to 20 nm. Order-disorder structural transformations in Co0.50Pt0.50 nanoalloys were studied. The magnetic properties of both chemically disordered Co0.50Pd0.50 and ordered CoPt clusters have also been measured.  相似文献   

19.
Colorless crystals of CsTh(MoO4)2Cl and Na4Th(WO4)4 have been synthesized at 993 K by the solid-state reactions of ThO2, MoO3, CsCl, and ThCl4 with Na2WO4. Both compounds have been characterized by the single-crystal X-ray diffraction. The structure of CsTh(MoO4)2Cl is orthorhombic, consisting of two adjacent [Th(MoO4)2] layers separated by an ionic CsCl sublattice. It can be considered as an insertion compound of Th(MoO4)2 and reformulated as Th(MoO4)2·CsCl. The Th atom coordinates to seven monodentate MoO4 tetrahedra and one Cl atom in a highly distorted square antiprism. Na4Th(WO4)4 adopts a scheelite superlattice structure. The three-dimensional framework of Na4Th(WO4)4 is constructed from corner-sharing ThO8 square antiprisms and WO4 tetrahedra. The space within the channels is filled by six-coordinate Na ions. Crystal data: CsTh(MoO4)2Cl, monoclinic, P21/c, Z=4, a=10.170(1) Å, b=10.030(1) Å, c=9.649(1) Å, β=95.671(2)°, V=979.5(2) Å3, R(F)=2.65% for I>2σ(I); Na4Th(WO4)4, tetragonal, I41/a, Z=4, a=11.437(1) Å, c=11.833(2) Å, V=1547.7(4) Å3, R(F)=3.02% for I>2σ(I).  相似文献   

20.
Three novel Th(IV) compounds containing heavy oxoanions, Th(SeO3)(SeO4) (1), Th(IO3)2(SeO4)(H2O)3·H2O (2), and Th(CrO4)(IO3)2 (3), have been synthesized under mild hydrothermal conditions. Each of these three distinct structures contain trigonal pyramidal and tetrahedral oxoanions. Compound 1 adopts a three-dimensional structure formed from ThO9 tricapped trigonal prisms, trigonal pyramidal selenite, SeO32-, anions containing Se(IV), and tetrahedral selenate, SeO42-, anions containing Se(VI). The structure of 2 contains two-dimensional porous sheets and occluded water molecules. The Th centers are found as isolated ThO9 tricapped trigonal prisms and are bound by four trigonal pyramidal iodate anions, two tetrahedral selenate anions, and three coordinating water molecules. In the structure of 3, the Th(IV) cations are found as ThO9 tricapped trigonal prisms. Each Th center is bound by six IO31- anions and three CrO42- anions forming a chiral three-dimensional structure. Second-harmonic generation of 532 nm light from 1064 nm radiation by a polycrystalline sample of 3 was observed. Crystallographic data (193 K, MoKα, λ=0.71073): 1; monoclinic, P21/c; , , , β=103.128(1), Z=4, R(F)=2.47% for 91 parameters with 1462 reflections with I>2σ(I); 2, monoclinic, P21/n, , , , β=100.142(2), Z=4, R(F)=4.71% for 158 parameters with 2934 reflections with I>2σ(I); 3, orthorhombic, P212121, , , , Z=4, R(F)=2.04% for 129 parameters with 2035 reflections with I>2σ(I).  相似文献   

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