首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
Synthesis and Crystal Structure of [Na(12-Crown-4)2]2[Hg(Se4)2] · 1.5 DMF . The title compound has been prepared by the reaction of Na2Se4 with mercury acetate in DMF solution in the presence of 15-crown-5, forming dark red crystal needles. [Na(12-crown-4)2]2[Hg(Se4)2] · 1.5 DMF crystallizes in the space group C2/c with eight formula units per unit cell. The structure was determined with 3 824 observed unique reflections, R = 0.085. Lattice dimensions at - 70°C: a = 2 884(2), b = 1 407.7(7), c = 2 843(2) pm, β = 93.93(5)°. The structure consists of [Na(12-crown-4)2]+ ions with a sandwichlike coordination of the crown ether molecules, and of [Hg(Se4)2]2? ions, in which the mercury atom is coordinated by two tetraselenido ions in a chelating fashion. The [Hg(Se4)2]2? ions are arranged to infinite chains via Se…?Se contacts.  相似文献   

2.
Crystal Structures of the Polytellurides [Ca(DMF)6]Te4, [Sr(15-Crown-5)2]Te4 · H2O, {[BaCl(18-Crown-6)(DMF)2]2[BaCl(18-Crown-6)(DMF) (H2O)]2(Te4)2}, and [Ph3PNPPh3]2Te5 · 2 DMF The title compounds were formed by alkalimetal polytelluride solutions in dimethylformamide (DMF) in the presence of the corresponding counter ions as well as in the presence of 15-crown-5 or 18-crown-6. Single crystals were obtained upon using additional diethylether. [Ca(DMF)6]Te4: Space group C2/c, Z = 4, 1024 observed unique reflections, R = 0.055. Lattice dimensions at ?70°C: a = 1776.1; b = 813.0 c = 2545.9pm; β = 102.90°. The compound consists of centrosymmetric [Ca(DMF)6]2+ ions, in which the calcium ions are octahedrally coordinated by the six oxygen atoms of the DMF molecules, and chain-like Te [Sr)15-crown-5)2]Te4 · H2O: Space group C2/c, Z = 4, 3322 observed unique reflections, R = 0.058. Lattice dimensions at ?70°C: a = 1450.5; b = 1407.3; c = 1660.9 pm; β = 110.22°. The compounds forms centrosymmetric cations [Sr(15-crown-5) 2]2+, in which the Sr2+ ion is sandwich-like surrounded by the ten oxygen atoms of the crown ether molecules, and chain-like Te42? ions, which are associated in the lattice forming polymeric chains. {[BaCl(18-crown-6)(DMF) 2]2[BaCl(18-crown-6)(DMF)· (H2O)] 2(Te4)2}: Space group P1 , Z = 1, 3189 observed unique reflections, R = 0.054. Lattice dimensions at 19°C: a = 986.1; b = 1052.8; c = 2696.4 pm; α = 89.34°; β = 88.68°; γ = 89.56°. The compound consists of chain-like Te ions without symmetry and of the two somewhat different cations [BaCl(18-crown-6)(DMF) 2]22+, in which the Ba2+ ions dimerize via centroysmmetric rings. Along with the six oxygen atoms of the crown ether molecules and the oxygen atoms of the DMF molecules, the oxygen atoms of the DMF and water molecule, respectively, the Ba+ ions achieve coordination number ten. [Ph3PNPPh3]2Te5 · 2DMF: Space group Pc, Z = 2, 5971 observed unique reflections, R = 0.058. Lattice dimensions at 20°C: a = 20°C: a = 1085.2; b = 1287.0; c = 2715.9 pm; β = 90.19°. The compounds consists of [Ph3PNPPh3]+ ions, chain-like Te52? ions, and incorporate DME molecules without bonding interaction. The 52? ions are associate via polymeric chains in which left- and right handed individuals are alternating.  相似文献   

3.
Synthesis and Crystal Structure of [Na(15-Crown-5)]4[Cd4Te12] · 8 DMF The title compound has been prepared by reaction of Na2Te3 with cadmium acetate in DMF solution in the presence of 15-crown-5, forming black crystal needles, which were characterized by an X-ray structure determination. Space group P21/n, Z = 2, 5 716 observed unique reflections, R = 0.038. Lattice dimensions at ?50°C: a = 1 622.9, b = 2 038.2, c = 1 739.8 pm, β = 92.26°. The compound has an ionic structure. The cations [Na(15-crown-5)(DMF)]+ and [Na(15-crown-5) · (DMF)2]+ together with two further DMF molecules form tetrameric units. In the centrosymmetric anions [Cd4Te12]4? the cadmium atoms are linked by μ2-Te2?-, μ4-Te22?-, and μ2-Te32?-units.  相似文献   

4.
Synthesis and Crystal Structure of the Nonaselenide [Sr(15-crown-5)2]Se9 The title compound was prepared by the reaction of excess selenium with strontium diselenide in DMF in the presence of 15-crown-5. [Sr(15-crown-5)2]Se9 forms black crystals, which are soluble in DMF. They were characterized by FIR spectroscopy and by an X-ray structure determination. Space group P21/n, Z = 4, 2 381 observed unique reflections, R = 0.073. Lattice dimensions at 19°C: a = 1 228.7, b = 1 893.4, c = 1 575.7 pm, β = 99.15°. The compound consists of [Sr(15-crown-5)2]2+ ions in which the strontium ion is coordinated by the oxygen atoms of the crown ether molecules in a sandwich-like fashion, and of Se92? ions with a chain structure, which has a topolocical resemblance with the bicyclic ion Se.  相似文献   

5.
Synthesis and Crystal Structures of the Polyellurido Complexes [K(15-Crown-5)2]2[MTe7] with M = Zn and Hg The title compounds were obtained in the presence of 15-crown 5 from solutions of zinc and mercury acetate, respectively, in DMF by addition of a solution of K2Te3 in DMF at 0°C (M = Zn) and -50°C (M = Hg). They form black crystal needles with metallic luster. Their crystal structures were determined by X-ray diffraction. The structures of [K(15-crown-5)2]2ZnTe7 and [K(15-crown-5)2]2HgTe7 show two-dimensional disorder as evidence by diffuse scattering. The averaged structures that were determined with the Bragg reflexions correspond to space group Pbcn and have very similar lattice parameters. Nevertheless, the structures differ. [HgTe7]2? ions consist of two condensed five membered rings. They are arranged to form strands in the c direction; within of one strand the ions have a definite orientation, but in different strands two different orientations occur randomly. A [ZnTe7]2? ion can be thought of consisting of a Zn2+ ion, a Te42? ion bonded in a chelate manner and a Te32? ion bonded with one terminal Te atom to the Zn2+. The [ZnTe7]2? ions are associated to strands in the c direction with two different strand orientations occuring randomly.  相似文献   

6.
Halogeno-Nitrosyl Complexes of Molybdenum and Tungsten. Crystal Structures of [Na2(15-Crown-5)2(CH3CN)][MoCl4(NO)2] and [Na(15-Crown-5)]2[MoF4Cl(NO)] MoCl2(NO)2 and WCl2(NO)2, respectively, react with excess sodium fluoride in acetonitrile at room temperature and in the presence of 15-crown-5 to give crystalline mixtures, which consist of the title compounds, respectively of [Na(15-crown-5)]2[WCl4(NO)2] and [Na(15-crown-5)]2[WF4Cl(NO)], and which can be separated by selection. The complexes are characterized by their i.r. spectra, the molybdenum compounds additionally by crystal structure determinations. [Na2(15-crown-5)2(CH3CN)][MoCl4(NO)2]: Space group P21, Z = 2, 5415 independent unique reflexions, R = 0.039. Lattice dimensions at ?10°C: a = 984.3, b = 1231.1, c = 1483.0 pm, β = 105.67°. The compound consists of cations [Ne(l5-crown-5)(CH3CN)]+, in which the sodium ion is surrounded by the five O-atoms of the crown ether and by the N-atom of the acetonitrile molecule, as well as of anions, which form an ion pair {Na(15-crown-5)[MoCl4(NO)2]}?. In the in pairs the sodium ion is coordinated by the five oxygen atoms of the crown ether and by two chlorine atoms of the [MoCI4(NO)2]2? unit. The nitrosyl ligands take the cis-position a t the molybdenum atom which is in a distorted octahedrally fashion. [Na(15-crown-5)]2[MoF4Cl(NO)]. Space group C2/c, Z = 4, 1933 independent unique reflexions, R = 0.078. Lattice dimensions at ?7O°C: D : 1.585.8, b = 1171.5, c = 1771.5 pm, β = 114.91°. The compound forms an ion triple, in which the sodium ions are linked to five oxygen atoms each of the crown ether molecules, and to two F-atoms of the [MoF4Cl(NO)]2? unit. The F-atom which is arranged in trans-position to the nitrosyl ligand coordinates with both sodium ions; thus an unusual T-shaped arrangement results for this F-atom. The sole terminal F-Atom and the Cl-atom are disordered in two positions.  相似文献   

7.
[K(15-Crown-5)2]2Te8 – a Bicyclic Polytelluride The octatelluride [K(15-crown-5)2]2Te8 has been synthesized by the oxydation of a potassium tritelluride solution in dimethylformamide by iron(III) chloride in the presence of 15-crown-5, forming black crystals, which were characterized by an X-ray structure determination. Space group Pca21, Z = 4, 4 548 observed unique reflections, R = 0.048. Lattice dimensions at –70°C: a = 1 881(1), b = 2 211(2), c = 1 530(1) pm. The structure consists of cations [K(15-crown-5)2]+, in which the potassium ions are sandwichlike coordinated by the oxygen atoms of the two disordered crown ether molecules, and of bicyclic Te82? ions. In these anions a Te2+ ion is chelated in a planar fashion by a Te32? and a Te42? unit.  相似文献   

8.
Amido Complexes of Manganese(II). Syntheses and Crystal Structures of [Mn(NPh2)2(THF)]2 and Na2[Mn(NPh2)4] · 2 C7H8 The silylated amido complex [Mn{N(SiMe3)2}2 · (THF)] reacts in toluene solution with diphenylamine under ligand exchange to form the diphenylamido complex [Mn(NPh2)2(THF)]2 ( 1 ), which forms orange-red columnar crystals. 1 reacts in THF solution with NaN(SiMe3)2 and after crystallization from toluene yellow-orange Na2[Mn(NPh2)4] · 2 C7H8 ( 2 ) is obtained. According to the crystal structure analyses the manganese atoms in 1 (space group P21/c, Z = 2) are linked via the N atoms of two of the NPh2 groups to form centrosymmetric Mn2N2 four-membered rings with Mn–N bonds of almost the same length. 2 (space group I41/a, Z = 4) forms a three-dimensional space-lattice structure, which arises from ”︁inner solvation”︁”︁ of the sodium atoms with the phenyl rings of the NPh2 group.  相似文献   

9.
The Crystal Structures of (NH4)2[ReCl6], [ReCl2(CH3CN)4]2[ReCl6] · 2CH3CN and [ReCl4(18)(Crown-6)] Brown single crystals of (NH4)2[ReCl6] are formed by the reaction of NH4Cl with ReCl5 in a suspension of diethylether. [ReCl2(CH3CN)4]2[ReCl6] · 2CH3CN crystallizes as brown crystal plates from a solution of ReCl5 in acetonitrile. Lustrous green single crystals of [ReCl4(18-crown-6)] are obtained by the reaction of 18-crown-6 with ReCl5 in a dichloromethane suspension. All rhenium compounds are characterized by IR spectroscopy and by crystal structure determinations. (NH4)2[ReCl6]: Space group Fm3 m, Z = 4, 75 observed unique reflections, R = 0.01. Lattice constant at ?70°C: a = 989.0(1) pm. The compound crystallizes in the (NH4)2[PtCl6] type, the Re? Cl distance is 235.5(1) pm. [ReCl2(CH3CN)4]2[ReCl6] · 2CH3CN: Space group P1, Z = 1, 2459 observed unique reflections, R = 0.12. Lattice dimensions at ?60°C: a = 859.0(1), b = 974.2(7), c = 1287.3(7) pm, α = 102.69(5)°, b? = 105.24(7)°, γ = 102.25(8)°. The structure consists of two symmetry-independent [ReCl2(CH3CN)4]+ ions with trans chlorine atoms, [ReCl6]2? ions, and included acetonitrile molecules. In the cations the Re? Cl bond lengths are 233 pm in average, in the anion they are 235 pm in average. [ReCl4(18-crown-6)]: Space group P21/n, Z = 4, 3 633 observed unique reflections, R = 0.06. Lattice dimensions at ?70°C: a = 1040.2(4), b = 1794.7(5), c = 1090.0(5) pm, b? = 108.91(4)°. The compound forms a molecular structure, in which the rhenium atom is octahedrally coordinated by the four chlorine atoms and by two oxygen atoms of the crown ether molecule.  相似文献   

10.
[Na(12-Crown-4)2]2[Ni(Se4)2] · DMF; Synthesis, Crystal Structure, and Magnetic Behaviour The title compound has been prepared from NiCl2 and sodium polyselenide in dimethylformamide solution in the presence of 12-crown-4, forming black crystal needles. They were characterized by an X-ray structure determination, by FIR spectroscopy as well as by the magnetic behaviour. [Na(12-crown-4)2]2[Ni(Se4)2] · DMF crystallizes monoclinically in the space group P21, 3650 observed unique reflections, R = 0.046. Lattice dimensions at ?80°C: a = 1020.3(2); b = 1889.5(2); c = 1498.7(3) pm; β = 108.29(1)°. The compound has an ionic structure, in which the sodium atoms of the [Na(12-crown-4)2]+ cations are coordinated by the oxygen atoms of the crown ether molecules in an antiprismatic fashion. The nickel atom of the anion [Ni(Se4)2]2? is surrounded by four selenium atoms of the tetraselenide chelates in an almost planar environment. The DMF molecules are inserted in the lattice without a bonding interaction. The magnetic susceptibility observed in the temperature interval 4.2 to 330K can be interpreted by means of a 3E ground term and D2 as local symmetry, which was established by X-ray crystallography.  相似文献   

11.
Syntheses and Crystal Structures of the Nitridodiolato Osmates(VI) PPh4[OsNCl2(O2C2H4)] and PPh4[OsNCl2(O2C2Me4)] · 2 THF The title compounds were prepared by the reaction of PPh4[OsNCl4] with glycole and pinacole, respectively, in CH2Cl2 and THF, respectively, in the presence of triethylamine, forming orange-red single crystals. According to the crystal structure determinations the compounds have ionic structures. In the anions the nitrido ligand occupies the apical position of the distorted tetragonal pyramid, and the two chlorine atoms and the two oxygen atoms of the diolato ligands are in equatorial positions. PPh4[OsNCl2(O2C2H4)] : Space group P21/n, Z = 4, 3 331 observed unique reflections, R = 0.031. Lattice dimensions at 19°C: a = 1 750.3, b = 816.8, c = 1 816.5 pm, β = 95.16°. PPh4[OsNCl2(O2C2Me4)] · 2 THF : Space group P1 , Z = 2, 5 238 observed unique reflections, R = 0.051. Lattice dimensions at -80°C: a = 898.9, b = 1 405.1, c = 1 518.6 pm, α = 93.66°, β = 92.89°, γ = 92.51°.  相似文献   

12.
Novel Suboxide Clusters [O5Ba18] in the Crystal Structures of Ba21M2O5 (M = Si, Ge) The compounds Ba21M2O5 (M = Si, Ge) crystallize in the cubic system with space group Fd3m, lattice constants 2 038.3(10) pm (Si), 2 039.8(9) pm (Ge) resp. and Z = 8. The crystal structure contains isolated Si/Ge atoms coordinated by barium atoms in an icosahedral arrangement. The oxygen atoms are situated in the centers of barium octahedra, four of which share common faces with an additional central octahedron. The novel clusters [O5Ba18] in principal are related to those in the crystal structures of the binary Cs/Rb suboxides.  相似文献   

13.
The Oxochlorotantalates (PPh4)2[Ta2OCl9]2 · 2 CH2Cl2, (PPh4)2[Ta2OCl10] · 2 CH3CN, and (K-18-crown-6)4[Ta4O6Cl12] · 12 CH2Cl2 (K-18-crown-6)4[Ta4O6Cl12] · 12 CH2Cl2 was obtained from a reaction of tantalum pentachloride, K2S5 and 18-crwon-6 in dichlormethane. According to its crystal structure analysis it is tetragonal (space group I 4 2d) and contains [Ta4O6Cl12]4– ions that have an adamantane-like Ta4O6 skeleton. Each K+ ion is coordinated by the oxygen atoms of the crown ether molecule from one side and with three Cl atoms of one [Ta4O6Cl12]4– ion from the opposite side. (PPh4)2[Ta2OCl10] · 2 CH3CN was a product from PPh4Cl and TaCl5 in acetonitrile in the presence of Na2S4. Its crystals are monoclinic (space group P21/c) and contain centrosymmetric [Ta2OCl10]2– ions having a linear Ta–O–Ta grouping with short bonds (Ta–O 189 pm). TaCl5 and H2S formed a solid substance (TaSCl3) from which a small amount of (PPh4)2[Ta2OCl9]2 · 2 CH2Cl2 was obtained by the reaction with PPh4Cl in CH2Cl2. The anions in the monoclinic crystals (space group P21/n) consist of two Ta2OCl9 units which are joined by chloro bridges; each Ta2OCl9 unit has a nearly linear Ta–O–Ta group with differing bond lengths (179 and 202 pm). The oxygen in the compounds probably was introduced by traces of water in the crown ether, acetonitrile or H2S, respectively.  相似文献   

14.
Synthesis, Crystal Structure, and 121Sb-Mössbauer Spectra of [SbBr3(15-Crown-5)], [SbBr2Me(15-Crown-5)], and [SbBr2Ph(15-Crown-5)] The compounds [SbBr3(15-crown-5)] ( 1 ), [SbBr2Me(15-crown-5)] ( 2 ), [SbBr2Ph(15-crown-5)] ( 3 ), and [SbCl2Me(15-crown-5)] ( 4 ) are formed by the reaction of 15-crown-5 with SbBr3, SbBr2Me, SbBr2Ph, and SbCl2Me, respectively, in toluene solution at ?40°C. The complexes were characterized by IR spectroscopy, 121Sb-Mössbauer spectroscopy, 1–3 as well as by X-ray structure determinations.
  • 1 : Space group P212121, Z = 4, 1735 observed, independent reflections, R = 0.050, Lattice dimensions at ?65°C: a = 787.03(7); b = 1313.0(2); c = 1619.3(2) pm.
  • 2 : Space group Pca21, Z = 8, 2730 observed, independent reflections, R = 0.050, Lattice dimensions at ?65°C: a = 1308.2(2); b = 1611.8(2); c = 1640.5(3) pm.
  • 3 : Space group P21/n, Z = 4,2458 observed, independent reflections, R = 0.040, Lattice dimensions at ?60°C: a = 900.3(3); b = 1390.6(6); c = 1618.5(7) pm, β = 96.32(3)°.
The complexes 1–3 have molecular structures, in which the antimony atoms are surrounded by the five oxygen atoms of the crown ether molecule and by three ligands Br3, Br2CH3, Br2Ph, respectively.  相似文献   

15.
Synthesis and Crystal Structure of [Ba(18-Crown-6)(DMF)4][Cd(Se4)2] The title compound has been prepared by the reaction of a DMF-solution of lithium polyselenide with BaSe2 and cadmium acetate in the presence of 18-crown-6, forming black crystals. The compound was characterized by IR spectroscopy and by an X-ray structure determination. Space group P2/a, Z = 4, 5392 observed unique reflections, R = 0.048. Lattice dimensions at ?90°C: a = 2021.9(12); b = 1019.8(6); c= 2270.8(14)pm, ß = 106.98(4)°. The structure consists of [Ba(18-crown-6)(DMF)4]2+ ions, in which the barium ions are coordinated by the six oxygen atoms of the crown ether molecule and by four oxygen atoms of the DMF molecules, and of [Cd(Se4)2]2? ions. The cadmium atoms are coordinated by two tetraselenide ions in a chelating fashion.  相似文献   

16.
Crystal Structures of the Hexachlorometalates NH4[SbCl6], NH4[WCl6], [K(18‐crown‐6)(CH2Cl2)]2[WCl6]·6CH2Cl2 and (PPh4)2[WCl6]·4CH3CN The crystal structures of the title compounds were determined by single crystal X‐ray methods. NH4[SbCl6] and NH4[WCl6] crystallize isotypically in the space group C2/c with four formula units per unit cell. The NH4+ ions occupy a twofold crystallographic axis, whereas the metal atoms of the [MCl6] ions occupy a centre of inversion. There exist weak interionic hydrogen bridges. [K(18‐crown‐6)(CH2Cl2)]2[WCl6]·6CH2Cl2 crystallizes in the orthorhombic space group R3¯/m with Z = 3. The compound forms centrosymmetric ion triples, in which the potassium ions are coordinated with a WCl3 face each. In trans‐position to it the chlorine atom of a CH2Cl2 molecule is coordinated so that, together with the oxygen atoms of the crown ether, coordination number 10 is achieved. (PPh4)2[WCl6]·4CH3CN crystallizes in the monoclinic space group P21/c with Z = 4. This compound, too, forms centrosymmetric ion triples, in which in addition the acetonitrile molecules are connected with the [WCl6]2— ion via weak C—H···Cl contacts.  相似文献   

17.
Phosphorane Iminato Complexes of Antimony. The Crystal Structures of [Sb2Cl5(NPMe3)2][SbCl6] · CH3CN and [SbCl(NPPh3)]2[SbCl6]2 · 6 CH3CN The title compounds are formed by reaction of antimony pentachloride in acetonitrile solution with the phosphorane iminato complexes SbCl2(NPMe3) and SbCl2(NPPh3), respectively, which themselves are synthesized by reaction of antimony trichloride with Me3SiNPR3 (R = Me, Ph). The complexionic compounds are characterized by 121Sb Mössbauer spectroscopy and by crystal structure determinations. [Sb2Cl5(NPMe3)2][SbCl6] · CH3CN: Space group P41, Z = 4, 3 698 observed unique reflections, R = 0.022. Lattice dimensions at ?60°C: a = b = 1 056.0(1), c = 2 709.6(2) pm. The structure consists of SbCl6? ions and cations [Sb2Cl5(NPMe3)2(CH3CN)]+, in which one SbIII atom and one SbV atom are bridged by the N atoms of the phosphorane iminato ligands. [SbCl(NPPh3)]2[SbCl6]2 · 6 CH3CN: Space group P1 , Z = 2, 5 958 observed unique reflections, R = 0.033. Lattice dimensions at ?60°C: a = 989.4(11), b = 1 273(1), c = 1 396(1) pm, α = 78.33(7), β = 77.27(8)°, γ = 86.62(8)°. The structure consists of SbCl6? ions and centrosymmetric cations [SbCl(NPPh3)(CH3CN)2]22+, in which the antimony atoms are bridged by the N atoms of the phosphorane iminato ligands.  相似文献   

18.
Synthesis and Crystal Structures of (PPh4)2[TeS3] · 2 CH3CN and (PPh4)2[Te(S5)2] (PPh4)2[TeS3] · 2 CH3CN was obtained by the reaction of PPh4Cl, Na2S4 and Te in acetonitrile. With sulfur it reacts yielding (PPh4)2[Te(S5)2]. The crystal structures of both products were determined by X-ray diffraction. (PPh4)2[TeS3] · 2 CH3CN: triclinic, space group P1 , Z = 2, R = 0.041 for 4 629 reflexions; it contains trigonal-pyramidal [TeS3]2? ions with an average Te? S bond length of 233 pm. (PPh3)2[Te(S5)2]: monoclinic, P21/n, Z = 2, R = 0.037 for 2 341 reflexions. In the [Te(S5)2]2? ion the tellurium atom has a nearly square coordination by four S atoms. Along with the Te atoms each of the two S5 groups forms a ring with chair conformation.  相似文献   

19.
Chloro- and Polyselenoselenates(II): Synthesis, Structure, and Properties of [Ph3(C2H4OH)P]2[SeCl4] · MeCN, [Ph4P]2[Se2Cl6], and [Ph4P]2[Se(Se5)2] By symproportionation of elemental selenium and SeCl4 in polar protic solvents the novel chloroselenates(+II), [SeCl4]2? and [Se2Cl6]2?, could be stabilized; they were crystallized with voluminous organic cations. They were characterized from complete X-ray structure analysis. Yellow-orange [Ph3(C2H4OH)P]2[SeCl4] · MeCN (space group P1 , a = 10.535(4), b = 12.204(5), c = 16.845(6) Å, α = 77.09(3)°, β = 76.40(3)°, γ = 82.75(3)° at 140 K) contains in its crystal structure monomeric [SeCl4]2? anions with square-planar coordination of Se(+II). The mean Se? Cl bond length is 2.441 Å. In yellow [Ph4P]2[Se2Cl6] (space group P1 , a = 10.269(3), b = 10.836(4), c = 10.872(3) Å, α = 80.26(3)°, β = 79.84(2)°, γ = 72.21(3)° at 140 K) a dinuclear centrosymmetric [Se2Cl6]2? anion, also with square-planar coordinated Se(+II), is observed. The average terminal and bridging Se? Cl bond distances are 2.273 and 2.680 Å, respectively. From redox reactions of elemental Se with boranate/thiolate in ethanol/DMF the bis(pentaselenido)selenate(+II) anion [Se(Se5)2]2? was prepared as a novel type of a mixed-valent chalcogenide. In dark-red-brown [Ph4P]2[Se(Se5)2] (space group P21/n, a = 12.748(4), b = 14.659(5), c = 14.036(5) Å, β = 108.53(3)° at 140 K) centrosymmetric molecular [Se(Se5)2]2? anions with square-planar coordination of the central Se(+II) by two bidentate pentaselenide ligands is observed (mean Se? Se bond lengths: 2.658 Å at Se(+II), 2.322 Å in [Se5]2?). The resulting six-membered chelate rings with chair conformation are spirocyclically linked through the central Se(+II). The vibrational spectra of the new anions are reported.  相似文献   

20.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号