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1.
Four complexes of MCl4 (M=Ti, Zr, Hf) with the hypervalent trifluoromethyl iodine reagent trifluoromethyl‐1,3‐dihydro‐3,3‐dimethyl‐1,2‐benziodoxole ( 1 ,=L) are described. With TiCl4, an I?O bond cleavage occurs, leading to the formation of the trifluoromethyliodonium alcoholate complexes [Ti2Cl6(L)4]Cl2 ( 2 a ) and Ti2Cl8(L) ( 2 b ). Reactions with ZrCl4 and HfCl4 form the complexes ZrCl4(L)2 ( 3 ) and HfCl4(L)2 ( 4 ), respectively, wherein the original I?O bond is retained and elongated compared to that in free 1 . Therefore, the reactivity of 1 can be easily and practically fine‐tuned by addition of different metal chlorides, following the order ZrCl4/HfCl4<TiCl4<2 TiCl4. Complexes 2 a , 3 , and 4 are remarkably bench‐stable forms of activated reagent 1 , while 2 b is readily accessible in situ. 2 a and 2 b represent the first “real” trifluoromethyliodonium reagents derived from iodanes, that is, with the I?O bond being completely cleaved. The new complexes were shown to be useful for the trifluoromethylation of para‐toluenesulfonate under aprotic conditions.  相似文献   

2.
Metal Ampoules as Mini‐Autoclaves: Syntheses and Crystal Structures of [Al(NH3)4Cl2][Al(NH3)2Cl4] and (NH4)2[Al(NH3)4Cl2][Al(NH3)2Cl4]Cl2 The salts [Al(NH3)4Cl2]+[Al(NH3)2Cl4]≡AlCl3 · 3 NH3 ( 1 ) and (NH4+)2[Al(NH3)4Cl2]+[Al(NH3)2Cl4](Cl)2≡ AlCl3 · 3 NH3 · (NH4)Cl ( 2 ) have been obtained as single crystals during the reactions of aluminum and aluminum trichloride, respectively, with ammonium chloride in sealed Monel metal containers. The crystal structure of 1 was determined again [triclinic, P‐1; a = 574.16(10); b = 655.67(12); c = 954.80(16) pm; α = 86.41(2); β = 87.16(2); γ = 84.89(2)°], that of 2 for the first time [monoclinic, I2/m; a = 657.74(12); b = 1103.01(14); c = 1358.1(3) pm; β = 103.24(2)°].  相似文献   

3.
The reaction of tellurium, tellurium tetrachloride, and ZrCl4 or HfCl4, respectively, under the conditions of chemical vapour transport in a temperature gradient 220 → 200 °C yields black crystals of Te6[ZrCl6] and Te6[HfCl6]. While Te6[ZrCl6] is formed almost quantitatively, Te6[HfCl6] is always accompanied by neighbored phases such as Te4[HfCl6] and Te8[HfCl6]. The crystal structures of Te6[ZrCl6] (orthorhombic, Pbcm, a = 1095.4(1), b = 1085.2(1), c = 1324.5(1) pm) and Te6[HfCl6] (a = 1094.8(2), b = 1086.3(2), c = 1325.0(2) pm) are isotypic and consist of one‐dimensional polymeric (Te62+)n cations and of discrete, only slightly distorted octahedral [MCl6]2‐ anions (M = Zr, Hf). The cations are build of five membered rings which are connected via single Te atoms to a polymer ‐Te‐Te5‐Te‐Te5‐. Out of the six Te atoms of the asymmetric unit of the chain four atoms exhibit two bonds and two atoms exhibit three bonds. The connecting, threefold coordinated Te atoms of the five membered rings carry formally the positive charges. In consistence with the assumption of the presence of throughout localized bonds eH band structure calculations for Te6[ZrCl6] show semiconducting behaviour with a band gap of 1.8 eV.  相似文献   

4.
E.P.R. and Ligand Field Spectra of Chlorovanadates(IV). The Crystal Structure of PPh4[VxTi2–xCl9] (x = 0.15) Black, moisture-sensitive crystals of PPh4[VxTi2–xCl9] (x = 0.15) are formed by the reaction of titanium tetrachloride and PPh4[VCl5] in dichloromethane. Its EPR and ligand field spectra as well as those of PPh4[VCl5] and (PPh4)2[V2Cl9][VCl5] · CH2Cl2 were recorded. In the mixed crystals of PPh4[V0.15Ti1.85Cl9], the existence of [VTiCl9]? ions consisting of trigonally distorted, face sharing octahedra can be proven by the spectra. The spectra of the compounds with [VCl5]? ions can only be explained when a significant Jahn-Teller distortion of the trigonal bipyramids is assumed; this distortion was not detected in the crystal structure determination of (PPh4)2[V2Cl9][VCl5] · CH2Cl2. The crystal structure of PPh4[V0.15Ti1.85Cl9] was determined by X-ray diffraction (2588 independent observed reflexions, R = 0.044). Crystal data: triclinic, space group P1 , a = 1090.4, b = 1217.4, c = 1287.7 pm, α = 73.19°, β = 69.87°, γ = 82.15°, Z = 2. The compound consists of PPh4 and [V0.15Ti1.85Cl9]? ions. In the anions, Ti and V atoms are distributed statistically in the two face sharing octahedra.  相似文献   

5.
For decades the chemistry of polyhalides was dominated by polyiodides and more recently also by an increasing number of polybromides. However, apart from a few structures containing trichloride anions and a single report on an octachloride dianion, [Cl8]2?, polychlorine compounds such as polychloride anions are unknown. Herein, we report on the synthesis and investigation of large polychloride monoanions such as [Cl11]? found in [AsPh4][Cl11], [PPh4][Cl11], and [PNP][Cl11]?Cl2, and [Cl13]? obtained in [PNP][Cl13]. The polychloride dianion [Cl12]2? has been obtained in [NMe3Ph]2[Cl12]. The novel compounds have been thoroughly characterized by NMR spectroscopy, single‐crystal Raman spectroscopy, and single‐crystal X‐ray diffraction. The assignment of their spectra is supported by molecular and periodic solid‐state quantum‐chemical calculations.  相似文献   

6.
The structures of four bis­(tri­chloro­phosphine)­iminium {[Cl3P=N=PCl3]+; systematic name: tri­chloro­[(tri­chloro­phos­phor­an­yl­idene)im­in­io]phos­phor­us(V)} salts, namely bis(tri­chloro­phosphine)­iminium hexa­chloro­niobate, (Cl6NP2)[NbCl6], (I), bis­(tri­chloro­phosphine)­iminium hexa­chloro­tantalate, (Cl6NP2)[TaCl6], (II), bis­(tri­chloro­phosphine)­iminium tri‐μ‐chloro‐bis­[tri­chloro­titanium(IV)], (Cl6NP2)[Ti2Cl9], (III), and bis­[bis­(tri­chloro­phosphine)­iminium] di‐μ‐chloro‐bis­[tetrachloro­zirconium(IV)], (Cl6NP2)2[Zr2Cl10], (IV), have been determined. The P=N distances in the discrete [Cl3P=N=PCl3]+ moieties in structures (I), (II) and (IV) range from 1.5460 (14) to 1.5554 (16) Å, and the P=N=P angles range from 136.8 (3) to 143.4 (4)°. The [Cl3P=N=PCl3]+ cation in (III) is disordered and the calculated geometries for the cation are therefore less reliable. Compounds (I) and (II) are isostructural and the metal anions have slightly distorted octahedral geometries. The anion in compound (III) consists of two distorted octahedral Ti centres linked by three μ2‐Cl atoms, while in compound (IV), the dianion is derived from two distorted edge‐shared ZrCl6 octahedra.  相似文献   

7.
The reaction of Se4[Mo2O2Cl8] with Se4[MCl6] (M = Zr, Hf) or of Se, SeCl4, MoOCl4, and MCl4 (M = Zr, Hf) at 120 °C in sealed evacuated glass ampoules gives (Se4)2[Mo2O2Cl8][MCl6] (M = Zr, Hf) in the form of dark‐green, air sensitive crystals in quantitative yield. The crystal structure analyses of both isotypic compounds (monoclinic, P21/c, Z = 2, a = 1336(2), b = 716(1), c = 1518(4) pm, β = 106.0(2)° for M = Zr; a = 1334.1(8), b = 715.03(9), c = 1518.2(3) pm, β = 106.00(2)° for M = Hf) show the presence of square‐planar Se42+, of dinuclear [Mo2O2Cl8]2—, and of almost regular octahedral [MCl6]2— ions. X‐ray crystallographic investigations on (Se4)2[Mo2O2Cl8][ZrCl6] give no hint for solid state phase transitions between —160 and 200 °C. This is in contrast to the related compounds Se4[Mo2O2Cl8] and Se4[ZrCl6] which both undergo phase transitions accompanied by reorientation of the cations and anions. (Se4)2[Mo2O2Cl8][ZrCl6] is paramagnetic and obeys the Curie‐Weiss law with a Weiss constant of —4(7) K indicating only weak interaction between the paramagnetic centres. The magnetic moment of 1.7(1) μB is consistent with the presence of MoV (d1 configuration) and supports the ionic formula.  相似文献   

8.
An innovative soft chemical approach was applied, using ionic liquids as an alternative reaction medium for the synthesis of tellurium polycationic cluster compounds at room temperature. [Mo2Te12]I6, Te6[WOCl4]2, and Te4[AlCl4]2 were isolated from the ionic liquid [BMIM]Cl/AlCl3 ([BMIM]+: 1‐n‐butyl‐3‐methylimidazolium) and characterized. Black, cube‐shaped crystals of [Mo2Te12]I6, which is not accessible by conventional chemical transport reaction, were obtained by reaction of the elements at room temperature in [BMIM]Cl/AlCl3. The monoclinic structure (P21/n, a = 1138.92(2) pm, b = 1628.13(2) pm, c = 1611.05(2) pm, β = 105.88(1) °) is homeotypic to the triclinic bromide [Mo2Te12]Br6. In the binulear complex [Mo2Te12]6+, the molybdenum(III) atoms are η4‐coordinated by terminal Te42+ rings and two bridging η2‐Te22– dumbbells. Despite the short Mo···Mo distance of 297.16(5) pm, coupling of the magnetic moments is not observed. The paramagnetic moment of 3.53 μB per molybdenum(III) atom corresponds to an electron count of seventeen. Black crystals of monoclinic Te6[WOCl4]2 are obtained by the oxidation of tellurium with WOCl4 in [BMIM]Cl/AlCl3. Tellurium and tellurium(IV) synproportionate in the ionic liquid at room temperature yielding violet crystals of orthorhombic Te4[AlCl4]2.  相似文献   

9.
Azido Complexes of Zirconium: ZrCl3N3, [ZrCl4N3]22?, [ZrCl4(N3)2]2?; Crystal Structure of (PPh4)2 [ZrCl4N3]2 Highly explosive ZrCl3N3 is formed by the reaction of ZrCl4 with iodine azide in dichloromethane suspension. According to the i.r. spectra, the compound is polymeric by azide and chlorine bridges. Zirconium tetrachloride reacts with one and two moles of tetraphenylphosphonium azide respectively, forming the thermally and mechanically stable complexes (PPh4)2[ZrCl4N3]2 and (PPh4)2[ZrCl4(N3)2]. The crystal structure of (PPh4)2[ZrCl4N3]2 was determined by X-ray methods (1942 reflexions, R = 6.5%). The complex crystallizes in the monoclinic space group P21/n with two formula units per unit cell. The structure consists of tetraphenylphosphonium cations and dimeric anions [ZrCl4N3]22?, in which the Zr atoms are linked by the α-N atoms of the azide groups, forming a centrosymmetric Zr2N2 ring with symmetry D2h. According to the i.r. spectra, the azide groups in the complex (PPh4)2[ZrCl4(N3)2] are covalently bonded at the Zr atom in trans positions.  相似文献   

10.
Colorless single crystals of Cd[AlCl4]2 grow from the melt of CdCl2 and AlCl3 upon slow cooling from 250°C. The crystal structure [monoclinic, P1a1, Z = 2, a = 1288.7(2), b = 660.2(1), c = 705.1(1) pm, β = 92.89(1)º] may be derived from hexagonally closest packed layers of Cl?. Octahedral and tetrahedral holes are filled with Cd2+ and Al3+ in a 1:2 ratio between all layers stacked in the [104] direction. Cd[GaCl4]2 and Cd[AlBr4]2 are isotypic. Reduction of Cd[AlCl4]2 with excess cadmium shot and slow cooling from 350°C yields plate-like very moisture-sensitive, colorless single crystals of Cd2[AlCl4]2. The crystal structure [triclinic, C1 , Z = 2, a = 655.47(3), b = 1135.26(1), c = 935.23(6) pm, α = 89.70(2)º, β = 103.61(1)º, γ = 90.455(1)º] is built from slabs stacked in the [100] direction consisting of ethane-like [Cd2Cl6] units with a Cd? Cd distance of 256.1 pm sharing common vertices with [AlCl4] tetrahedra.  相似文献   

11.
Reactions of Zirconium Tetrachloride with Trithiazylchloride. Crystal Structure of (S4N4)[Zr2Cl10] Zirconium tetrachloride reacts with (NSCI)3 yielding (S3N3CI2)2[Zr2CI10], S4N4[Zr2CI10], or (S4N4CI)2[Zr2CI10], depending of the reaction conditions. These compounds were characterized by their i.r. spectra. They have an ionic structure containing the known ions S3N3CI2⊕, S4N42⊕, S4N4CI, and the thus far unknown [Zr2CI10]2? ion. According to the X-ray structure determination (2827 independent observed reflexions, R = 0.027), (S4N4CI)2[Zr2CI10] crystallizes in the space group P&1macr; with the lattice constants a = 688, b = 1132, c = 1827 pm, α = 103.2°, β = 98.7° and γ = 91.90 and with Z = 2 formula units per unit cell. The structure is built up from S4N4CI ions, which are nearly identical as in S4N4CI[FeCI4] and from [Zr2CI10]2? ions in which two chloro bridges join two edge-sharing octahedra.  相似文献   

12.
The compounds tert‐butylarsenium(III) tri‐μ‐chlorido‐bis[trichloridotitanium(IV)], (C4H12As)[Ti2Cl9] or [tBuAsH3][Ti2(μ‐Cl)3Cl6], (II), and bis[bromidotriphenylarsenium(V)] di‐μ‐bromido‐μ‐oxido‐bis[tribromidotitanium(IV)], (C18H15AsBr)2[Ti2Br8O] or [Ph3AsBr]2[Ti2(μ‐O)(μ‐Br)2Br6], (III), were obtained unexpectedly from the reaction of simple arsane ligands with TiIV halides, with (II) lying on a mirror plane in the unit cell of the space group Pbcm. Both compounds contain a completely novel ion, with [tBuAsH3]+ constituting the first structurally characterized example of a primary arsenium cation. The oxide‐bridged titanium‐containing [Ti2(μ‐O)(μ‐Br)2Br6]2− dianion in (III) is also novel, while the bromidotriphenylarsenium(V) cation is structurally characterized for only the second time.  相似文献   

13.
Crystal Structures of (Ph4P)2[HfCl6]·2CH2Cl2 and (Ph4P)2[Hf2Cl10]·CH2Cl2 Colourless single crystals of (Ph4P)2[HfCl6]·2CH2Cl2 ( 1 ) and (Ph4P)2[Hf2Cl10]·CH2Cl2 ( 2 ) were obtained from hafniumtetrachloride and tetraphenylphosphonium chloride in dichloromethane solution, using the corresponding stoichiometry of the educts. Both compounds were characterized by X‐ray structure determinations. 1 : Space group P1¯, Z = 1, lattice dimensions at 193 K: a = 1018.3(1), b = 1121.0(1), c = 1240.1(1) pm, α = 70.55(1)°, β = 81.38(1)°, γ = 80.02(1)°, R1 = 0.0374. 2 : Space group P1¯, Z = 1, lattice dimensions at 193 K: a = 1124.4(1), b = 1141.9(1), c = 1281.4(1) pm, α = 63.80(1)°, β = 68.15(1)°, γ = 86.33(1)°, R1 = 0.0208.  相似文献   

14.
Adducts and Salts Formed by Sulphurchlorides with AlCl3 The instability of the adduct 2 S2Cl2 · AlCl3 is proven. S2Cl2 · AlCl3 and S2Cl2 · 2 AlCl3 reported in the literature could not be found under proper conditions, their formation seems improbable. The product 2 SCl4 · 3 AlCl3, obtained by the reaction of [SCl3]+[AlCl4]? with elementary sulphur, is characterized as a double salt [SCl3]2+[AlCl4]? [Al2Cl7]?. The [Al2Cl7]? anion is also found as an intermediate during the thermal decomposition of [SCl3]+[AlCl4]? and when metallic aluminium reacts directly with S2Cl2. For SCl2 · AlCl3, the ionic character with a chlorsulfenium cation [SCl]+ is proven spectroscopically.  相似文献   

15.
报道了一类咪唑环阳离子上同时含有氯和氟元素的新型离子液体,即 和 。这类离子液体是将其前驱体甲基丁基咪唑氯盐或甲基丁基咪唑六氟磷酸盐经过氯化取代和氟化取代反应来制备的。采用氢核磁共振谱(1H-NMR)确定了氯化反应过程中氯取代氢的位置,结果表明,氯主要取代咪唑环上的氢以及部分丁基侧链上甲基基团中的氢。考察了这类离子液体的水溶性,热稳定性以及黏度。结果表明,离子液体经氯化和氟化处理可以显著提高其憎水性。  相似文献   

16.
Na5[CuO2][CO3], Na5[CuO2][SO3], Na5[CuO2][S], and Na5[CuO2][SO4] were obtained as single crystals and powders from reactions of Na2O, Cu2O, and Na2X with X = CO32—, SO32—, S2—, and SO42—, respectively. A redox reaction between CdO and Co metal occurs in the presence of Na2O and Na2X, yielding Na5[CoO2][X] with X = CO32— and S2—. From a mixture of Na2SO4, CdO and Na2O in Ni‐containers we observed the formation of Na5[NiO2][S] single crystals. Single crystals of Na25[CuO2]5[SO4]4[S] can be grown by annealing Na5[CuO2][SO3] at 600 °C, leading to the decomposition of SO32—, yielding SO42— and S2— at 550 °C. The structures have been determined from single crystal data and powder data. All structures contain the isolated complex [MO2]3— in a dumb‐bell like arrangement. The main feature of these compounds is that the anions SO42—, SO32—, CO32— and S2— are not connected to the transition metal. The formation of Na5[CuO2][X] (X = S2—, SO42—, SO32—, CO32—) has been studied by thermal analysis and in situ X‐ray diffraction techniques. Infrared spectra confirm the presence of SO42—, SO32—, and CO32—, respectively, in the structures.  相似文献   

17.
On the Mechanism of the Thermal Decomposition of Ammonium and Ammin Chloro Complexes of Ruthenium, Rhodium, Palladium and Platinum The thermolysis of noble metal compounds was investigated by a combination of independent physical (DTA/TG, high-temperature Guinier-Simon-technique) and preparative methods, characterization of the educts, intermediats and products by Guinier X-ray patterns and IR spectroscopy:
  • (a) (NH4)2[PtCl6], (NH4)2[PtCl4], [Pt(NH3)4][PtCl4], [Pt(NH3)4]Cl2, and trans-[Pt(NH3)2Cl2];
  • (b) (NH4)2[PdCl4], [Pd(NH3)4]Cl2, trans-[Pd(NH3)2Cl2], and [Pd(NH3)4][PdCl4];
  • (c) (NH4)2[RhCl5(H2O)], (NH4)3[Rh2Cl9], K2[RhCl5(H2O)], and K2[RhCl5(NH3)];
  • (d) (NH4)2[RuCl5(NH3)] and (NH4)4[Ru2Cl10O]
. The most important step of the mechanism of the thermal decomposition is the ?internal”? redox reaction between the noble metal cation and the nitrogen atom of the ammine ligand.  相似文献   

18.
S5N5 [GaCl4]? and S5N5 [Ga2Cl7]?. Synthesis, IR Spectra, and Crystal Structures . S5N5[GaCl4] was obtained in high yields from gallium and trithiazyl chloride; depending on the solvent, different second products are formed: S4N4Cl[GaCl4] in dichloromethane and S3N2Cl[GaCl4] in carbon tetrachloride. These products can be separated due to their high solubility in CH2Cl2, S5N5[GaCl4] being only slightly soluble. S3N2Cl[GaCl4] can be converted to S5N5[GaCl4] with additional (NSCl)3. By the action of GaCl3 on S5N5[GaCl4], S5N5[Ga2Cl7] is formed. The IR spectra of the title compounds are reported; they differ considerably as well in number as in frequencies of the cation bands and show that the S5N5 ion has different structures depending on the anion. The crystal structures of both compounds were determined by X-ray diffraction. Crystal data: S5N5[GaCl4], orthorhombic, a = 943.8, b = 1369.0, c = 2068.8 pm, space group Pnma, Z = 8 (1381 observed reflexions, R = 0.075); S5N5[Ga2Cl7], monoclinic, a = 847.5, b = 1298.2, c = 1654.0 pm, β = 93.51°, space group P21/n, Z = 4 (1359 observed reflexions, R = 0.065). S5N5[GaCl4] is isotypic with S5N5[AlCl4], showing a heartshaped S5N5 ion, but large ellipsoids of vibration suggest the presence of some kind of disorder (statical or dynamical). In S5N5[Ga2Cl7] the S5N5 has an azulene-like structure. In both cases the cations are planar, all S? N bond lengths being approximately equal.  相似文献   

19.
Phosphoraneiminato Complexes of Titanium. Synthesis and Crystal Structures of CpTiCl2(NPMe3), [TiCl3(NPMe3)]2, [Ti2Cl5(NPMe2Ph)3], and [Ti3Cl6(NPMe3)5][BPh4] The title compounds are formed from Cp2TiCl2 and titanium tetrachloride, respectively, and the corresponding phosphane imino compounds Me3SiNPMe3 and Me3SiNPMe2Ph. The tetraphenyl borate salt yielded from the reaction of [Ti3Cl6(NPMe3)5]Cl with NaBPh4. All compounds form yellow crystals which are sensitive to moisture. They were characterized by IR-spectroscopy and crystal structure analyses. CpTiCl2(NPMe3) ( 1 ): Space group Pbca, Z = 8, solution of the structure with 1632 observed independent reflections, R = 0.037. Lattice dimensions at 19°C: a = 1202.6, b = 1224.2, c = 1766.7 pm. The molecules of the compound are monomeric with the (NPMe3)? ligand in almost linear array (bond angle Ti? N? P 170.7°). [TiCl3(NPMe3)]2 ( 2 ): Space group Pbca, Z = 8, structure solution with 698 observed independent reflections, R = 0.030. Lattice dimensions at ?60°C: a = 1140.5, b = 1112.2, c = 1589.4 pm. In 2 the titanium atoms, which occur in trigonal bipyramidal coordination, are linked by the N atoms of the (NPMe3)? groups to form a centrosymmetric dimer with Ti? N bond lengths of 184.3 and 208.2 pm. [Ti2Cl5(NPMe2Ph)3] · CH2Cl2 ( 3 ): Space group Pca21, Z = 4, structure solution with 8477 observed independent reflections, R = 0.051. The lattice dimensions at 20°C are: a = 1221.0; b = 1407.5, c = 2139.3 pm. 3 can be understood as a reaction product of TiCl2(NPMe2Ph)2 and TiCl3(NPMe2Ph). In the resulting, heavily distorted Ti2N2-four-membered ring the Ti? N bond lenghts are 1804., 194.4, 199.2, and 234.6 pm. The longest Ti? N bond is in trans-position to the N atom of the terminal (NPMe2Ph)- ligand, in which the Ti? N distance is 175.6 pm. .[Ti3CL6(NPMe3)5][BPh4] (4): Space group P21/n, structure solution with 2846 observed independent reflections, R = 0.062. The lattice dimensions at 20°C are: a = 1495.2, b = 2335.4, c = 155,8 pm, β = 93.28°. In the cation of 4 the three titanium atoms along with three (NPMe3)- groups with μ2- N functions and two (NPMe3)- groups with μ3- N functions form a nation number 6 with two terminal chlorine atoms.  相似文献   

20.
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   

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