Halogenomercurate: Darstellung und Strukturen von [Cu(en)2][Hg2Cl6], [Cu(en)2][Hg2Br6] und [Cu(en)2][HgBr4]

Halomercurates: Syntheses and Crystal Structures of [Cu(en)₂][Hg₂Cl₆], [Cu(en)₂][Hg₂Br₆], and [Cu(en)₂][HgBr₄] Crystals of [Cu(en)₂][Hg₂Cl₆] ( 1 ) have been obtained by layering a solution of Hg(NO₃)₂ and NaCl with a solution of [Cu(en)₂]SO₄. An analogous procedure, using NaBr instead of NaCl, gave crystals of [Cu(en)₂][HgBr₄] ( 3 ). Crystals of [Cu(en)₂][Hg₂Br₆] ( 2 ) were obtained by gel crystallization using the same starting materials as for 3 . The complexes show very low solubility. The dinuclear anions of 1 consist of two nearly planar HgCl₃ units related by a center of symmetry. In 2 infinite anionic chains are present, made up of parallel HgBr₃ units. These units are packed in such a way as to produce a trigonal bipyramidal configuration around the Hg atoms. 3 contains mononuclear deformed tetrahedral [HgBr₄]^2– anions. In all three complexes the packing of the ions is such that halogen atoms of halomercurate anions complete a tetragonal bipyramidal coordination at Cu. The resulting Cu–Halogen distances are 2.924 Å for 1 , 3.036 Å for 2 and 3.085 and 3.119 Å for 3 . 1 : Space group P 1, Z = 1, lattice constants at 20 °C: a = 7.000(2), b = 7.526(2), c = 8.239(2) Å; α = 88.39(2), β = 86.06(2), γ = 86.10(3)°; R₁ = 0.040. 2 : Space group P2₁/c, Z = 2, lattice constants at –50 °C: a = 7.185(1), b = 16.338(2), c = 7.814(1) Å; β = 94.88(2)°; R₁ = 0.033. 3 : Space group P2₁/n, Z = 4, lattice constants at 20 °C: a = 8.055(3), b = 13.101(3), c = 13.814(3) Å; β = 91.24(3)°; R₁ = 0.092.     

Ortho‐Chalcogenotetrelate Anions as Chelating Ligands: Syntheses and Characterization of [K6(MeOH)9][Sn2Se6][Cr(en)2(SnSe4)]2, [Na(H2O)4][Cr(en)3]2[GeS3OH]2[Cr(en)2(GeS4)], and [Ba(H2O)10][{Cr(en)}2(GeSe4)2]

Reactions of K₄[SnSe₄], Na₄[GeS₄] or Ba₂[GeSe₄] with different 1,2‐diaminoethane (= en) coordinated complexes of CrCl₃ ([Cr(en)₂Cl₂]Cl or [Cr(en)₃]Cl₃) in MeOH or aqueous solution yielded three novel compounds that contain complexes of Cr³⁺ with ortho‐chalcogenotetrelate anions [E′E₄]^4? (E′ = Ge, Sn; E = S; Se): the crystal structures of [K₆(MeOH)₉][Sn₂Se₆][Cr(en)₂(SnSe₄)]₂ ( 1 ), [Na(H₂O)₄][Cr(en)₃]₂[GeS₃OH]₂[Cr(en)₂(GeS₄)] ( 2 ), and [Ba(H₂O)₁₀][{Cr(en)}₂(GeSe₄)₂] ( 4 ) have been determined by means of single crystal X‐ray diffraction ( 1 : triclinic space group ; lattice dimensions at 203 K: a = 1175.7(2), b = 1315.3(3), c = 1326.7(3) pm, α = 61.99(3)°, β = 64.05(3)°, γ = 83.57(3)°, V = 1617.4(6)·10⁶ pm³; R₁ [I > 2σ(I)] = 0.0788; wR₂ = 0.1306; 2 : monoclinic space group C2/c; lattice dimensions at 203 K: a = 2445.3(5), b = 1442.5(3), c = 1579.3(3) pm, β = 94.61(3)°, V = 5552.9(19)·10⁶ pm³; R₁ [I > 2σ(I)] = 0.0801; wR₂ = 0.2046; 4 : triclinic space group ; lattice dimension at 203 K: a = 1198.4(2), b = 1236.8(3), c = 1297.5(3) pm, α = 65.69(3)°, β = 63.35(3)°, γ = 81.21(3)°, V = 1565.2(5)·10⁶ pm³; R₁ [I > 2σ(I)] = 0.0732; wR₂ = 0.1855). 1 and 2 show the yet unprecedented complexation of transition metal ions by non‐bridging, single chalcogenotetrelate ligands to produce dinuclear, heterobimetallic complexes. Compound 2 contains the first structurally characterized complex with an ortho‐thiogermanate ligand. The formation of these compounds, and of a by‐product of 2 , [Cr(en)₃][GeS₃OH]·6H₂O ( 3 : monoclinic space group C2/c; lattice dimensions at 203 K: a = 2396.8(5), b = 1463.4(3), c = 1740.1(4) pm, β = 132.99(3)°, V = 4463.8(15)·10⁶ pm³; R₁ [I > 2σ(I)] = 0.0462; wR₂ = 0.1058), provides some insight in fundamental differences between the reaction behavior of [SnE₄]^4? anions one the one hand and [GeE₄]^4? anions on the other hand. The crucial role of the counterion charge becomes evident when comparing the structure motifs of the ternary anions in 1 and 2 with that observed in the Ba²⁺ compound 4 .     

Preparation and structural characterization of three types of homo- and heterotrinuclear boron complexes: salen[[B-O-B][O2BOH]], salen[[B-O-B][O2BPh]], and salen[[B-O-B][O2P(O)Ph]

Three types of homo- and heterotrinuclear boron complexes have been obtained in moderate to good yields from reactions of salen-type ligands with boric acid and combinations of boric acid with phenylboronic and phenylphosphonic acid. The products are air-stable and have relatively high melting points (>290 degrees C) but are poorly soluble or insoluble in common organic solvents. They have been characterized as far as possible by elemental analysis, mass spectrometry, IR, (1)H, (11)B, and (31)P NMR spectroscopy, and X-ray crystallography. Furthermore, theoretical calculations have been performed for representative examples to permit a complete comparison of the different structure types. A detailed analysis of the molecular structures showed that the complexes are constructed around a central B(3)O(3) or B(2)PO(3) ring. The salen ligands are attached to two boron atoms of these rings, which have therefore tetrahedral coordination geometries. The complexes contain seven- and eight-membered heterocycles of the B(2)C(n)ON(2) (n = 2, 3) type with chair or twisted-chair and boat-chair or chair-chair conformations, respectively. In the homotrinuclear complexes one of the three boron atoms is three-coordinate and can therefore still act as Lewis acid, thus making these products interesting for catalytic applications, e.g. in asymmetric synthesis. Depending on the substitutents attached to the boron atoms, these complexes show a relationship with either trimetaboric acid, boroxine, or the tetraborate dianion found in Borax.     

Synthesis and Structure of Co(III) Coordination Compounds [Co(DH)2(Anil)2][BF4] and [Co(DH)2(Py)2][BF4]

The complex compounds [Co(DH)₂(Anil)₂][BF₄] and [Co(DH)₂(Py)₂][BF₄] were synthesized from Co(BF₄)₂ · 6H₂O–DH₂–A–alcohol–water systems (DH₂ is dimethylglyoxim and A is pyridine (Py) or aniline (Anil)), and their crystal structures were determined using X-ray diffraction analysis. In octahedral Co(III) complexes, two dimethylglyoxime radicals lie in the equatorial plane and are joined via the intramolecular hydrogen bond O–H···O. The complexes with pyridine and aniline have similar configurations but different crystal structures.     

Thermolysis of [Co(NH3)6][Cr(C2O4)3]

Thermolysis of the double-metal complex [Co(NH₃)₆][Cr(C₂O₄)₃] was studied in air at 200, 350, and 500°C and in a hydrogen atmosphere at 200, 350, 500, 700, and 900°C, as well as the composition and properties of thermolysis products. Oxidative thermolysis produces mixed oxides CoCr₂O₄ and Co₂CrO₄; reductive thermolysis produces Co + Cr₂O₃ mixture. Specific surface areas were measured for reductive thermolysis products; the maximal specific surface area and, therefore, maximal dispersion are reached at 500°C. The morphology of the reductive thermolysis products and the thermolysis chemism were studied in relation to the nature of the complex anion.     

钴的二膦酸配合物[ Co(en) 3 ] [ Co2 (Hedbbp) 2 ]· 7H2O的合成与晶体结构

水热条件下合成了一个新的有机二膦酸钴配合物[Co(en)3][Co2(Hedbbp)2]·7H2O,[H4edbbp=N,N'-二(苄基膦酸)乙二胺].X射线单晶衍射结构分析表明配合物属三斜晶系,空间群P-1,晶胞参数a=1.505.6(3)nm,b=1.524 8(3)nm,c=1.649 7(3)nm,α=63.10(3)°,β=78.12(3)°,γ=75.62(3)°,晶胞 体积为V=3.2524(11)nm3,Z=2.配合物结构单元中包含一个二膦酸钴的二聚单元阴离子[Co2(Hedbbp)2]2-和一个三乙二胺合钴螯合阳离子单元[Co(en)3]2+和七个水分子.     

Enantioselective resolutions and circular dichroism studies of lanthanide-containing Keggin-type [Ln(PW11O39)2](11-) polyoxometalates

Enantiopure crystals of K(1.3)Na(3.2)H(6.5)[l-Pr(PW(11)O(39))(2)]·8.3l-proline·21.5H(2)O (1), K(1.3)Na(3.2)H(6.5)[d-Pr(PW(11)O(39))(2)]·8.3d-proline·17H(2)O (2), and K(1.3)Na(3.2)H(6.5)[l-Er(PW(11)O(39))(2)]·8.3l-proline·22.5H(2)O (3) were successfully obtained by using l- and d-proline (pro) as chiral auxiliary agents. In these crystals, l- and d-[Ln(PW(11)O(39))(2)](11-) anions are attached by two l- and d-pro molecules, respectively, through a O···N hydrogen-bonding interaction between the square-antiprismatic LnO(8) center and amino-N atoms. The l- and d-[Pr(PW(11)O(39))(2)](11-) anions in aqueous solutions exhibited a couple of mirror-imaged CD spectra due to (3)H(4/2)→(3)P(0,1,2) and (1)D(2) transitions in the stereogenic Pr(3+) center. Chirality inductions by l- and d-pro from a racemic solution of [Er(PW(11)O(39))(2)](11-) was demonstrated by means of CD spectroscopy.     

Synthesis, crystal structure and properties of a new organic-inorganic hybrid Dawson-like polyoxotungstate [Co(2,2''-bpy)3]2[Co(2,2''-bpy)2Cl][Co(2,2''-bpy)2]H2-[SbW18O60]·4H2O

A new organic-inorganic hybrid polyoxometalate based on Dawson-like polyoxotungstate anion [SbW18O60]9-, formulated [Co(2,2'-bpy)3]2[Co(2,2'-bpy)2Cl][Co(2,2'-bpy)2]H2[SbW18O60]·4H2O (2,2'-bpy= 2,2(-bipyridine) has been synthesized from Sb2O3, Na2WO4, CoCl2, and 2,2'-bipyridine materials by hydrothermal method, and which was characterized by elemental analyses, IR, XPS, EPR, TG, and X-ray single crystal diffraction. Structure analysis shows that the polyoxoanion self-assembled under hydrothermal conditions consists of a Dawson-like polyoxotungstate cluster anion [SbW18O60]9- encapsulating a pyramidal {SbO3} group within the {W18} cluster cage. EPR spectra show that the high-spin octahedral CoⅡ and low-spin CoⅡ ions coexist in the title compound. Magnetic properties indicate that the compound is antiferromagnetic.     

新型杂多酸[Bu4N][Ni(pph3)2]PW11O39硅溶胶修饰电极电化学性质及电催化研究

采用溶胶-凝胶技术制备了新多金属氧酸盐[Bu4N][Ni(pph3)2]PW11O39(Bu为四丁基,pph为苯基磷)有机-无机杂化材料修饰电极,该修饰电极不仅保持了本体溶液的电化学和电催化性质,而且还具有很好的稳定性与灵敏度.研究表明,优选条件下修饰电极在pH=4.5的缓冲溶液中,其催化电流与NO2-浓度在6.0×10-6~1×10-3mol/L范围内呈良好的线性关系,对不同基质环境水样的加标回收率为97%~102%,方法的检出限为1.0×10-7mol/L,对1.0×10-4mol/L NO2-平行测定10次的相对标准偏差(RSD)为1.96%.     

Co(en)3[B4O5(OH)4]Cl·3H2O和[Ni(en)3][B5O6(OH)4]2·2H2O的合成、结构以及热力学性质

利用水热法合成了两种过渡金属配合物为模板剂的含水硼酸盐晶体Co(en)3[B4O5(OH)4]Cl·3H2O(1) 和 [Ni(en)3][B5O6(OH)4]2·2H2O (2),并通过元素分析、X射线单晶衍射、红外光谱及热重分析对其进行了表征。化合物1晶体结构的主要特点是在所有组成Co(en)33+, [B4O5(OH)4]2–, Cl– 和 H2O之间通过O–H…O、O–H…Cl、N–H…Cl和N–H…O四种氢键连接形成网状超分子结构。化合物2晶体结构的特点是[B5O6(OH)4]–阴离子通过O–H…O氢键连接形成沿a方向有较大通道的三维超分子骨架,模板剂[Ni(en)3]2+阳离子和结晶水分子填充在通道中。     

Synthesis and structure of asymmetric zirconium-substituted silicotungstates, [Zr6O2(OH)4(H2O)3(beta-SiW10O37)3]14- and [Zr4O2(OH)2(H2O)4(beta-SiW10O37)2]10-

The reaction of ZrCl4 with [gamma-SiW10O36]8- in a potassium acetate buffer results in two different products depending on the reactant ratios. The trimeric species [Zr6O2(OH)4(H2O)3(beta-SiW10O37)3]14- (1) consists of three beta23-SiW10O37 units linked by an unprecedented Zr6O2(OH)4(H2O)3 cluster with C1 point group symmetry. The dimeric species [Zr4O2(OH)2(H2O)4(beta-SiW10O37)2]10- (2) consists of beta22- and beta12-SiW10O37 units sandwiching a Zr4O2(OH)2(H2O)4 cluster, which also has C1 symmetry. Polyanion 1 contains more zirconium centers than any other polyoxometalate known to date.     

Magnetic and spectroscopic properties of [Co(AGlH)2py2][Cr(NH3)2NCS)4] and [Co(AGlH)2py2][Co(NH3)2(NO2)4] complexes

The magnetic and spectroscopic (UV, visible-IR and electron paramagnetic resonance spectra) properties of the molecular complexes [Co(AGlH)₂py₂][Cr(NH₃)₂(NCS)₄] and [Co(AGlH)₂py₂][Co(NH₃)₂(NO₂)₄] (where AGlH₂ is diaminoglyoxime) have been examined in solid state. The molecular structure of the complexes and the nature of the interaction in the crystals has been considered.     

Structural and Thermal Studies on the Ion-pairs [Co(NH3)6]5[HV10O28]3·18H2O and [Co(NH3)6][V2O6OH]

Two cobalt hexammine-vanadate ion-pair complexes have been prepared; one in acid medium (pH≈4) and the other in alkaline medium (pH≈10). The formed complexes were characterized by their elemental analysis, IR and XRD techniques. The complexes were subjected to thermogravimetric and differential thermal analyses. The IR study suggests that the formed complexes were of the ion-pair type, while that of the thermally decomposed compounds revealed the resolution of the originally present broad V=O and V-O-V bands. This revised version was published online in July 2006 with corrections to the Cover Date.     

Decarboxylative Trifluoromethylating Reagent [Cu(O2CCF3)(phen)] and Difluorocarbene Precursor [Cu(phen)2][O2CCF2Cl]

This article describes the new economic decarboxylative trifluoromethylating reagent [Cu(phen)(O₂CCF₃)] ( 1 ; phen=1,10‐phenanthroline) and the efficient difluorocarbene precursor [Cu(phen)₂][O₂CCF₂Cl] ( 2 ). Treatment of copper tert‐butoxide with phen and subsequent addition of trifluoroacetic acid or chlorodifluoroacetic acid afforded air‐stable complexes 1 and 2 , respectively, which were characterized by X‐ray crystallography. The copper(I) ion in 1 is coordinated by a bidentate phen ligand, a monodentate trifluoroacetate group, and a molecule of CH₃CN in a distorted tetrahedral coordination geometry. The molecular structure of 2 adopts an ionic form that consists of a [Cu(phen)₂]⁺ cation and a chlorodifluoroacetate anion. Complex 1 reacted with a variety of aryl and heteroaryl halides to form trifluoromethyl (hetero)arenes in good yields. The corresponding Hammett plot exhibited a linear relationship and a reaction parameter (ρ)=+0.56±0.02, which indicated that the trifluoromethylation reaction proceeded via a nucleophilic reactive species. Complex 2 reacts with phenols to produce aryl difluoromethyl ethers in modest‐to‐excellent yields. Mechanistic investigations revealed that the difluoromethylation reaction proceeds by initial copper‐mediated formation of difluorocarbene and subsequent concerted addition of difluorocarbene to the phenol to form a three‐center transition state.