H(OEt2)2[P(1,2‐O2C6Cl4)3]: Synthesis,Characterization, and Application as a Single‐Component Initiator for the Carbocationic Polymerization of Olefins

The development of novel Brønsted acids featuring the hexacoordinate phosphorus(V) anion [TRISPHAT]^? {[ 1 ]^?=[P(1,2‐O₂C₆Cl₄)₃]^?} are reported. The title compound, H(OEt₂)₂[ 1 ], was synthesized from 1,2‐(HO)₂C₆Cl₄ (3 equiv) and PCl₅ in the presence of diethyl ether. This compound was fully characterized by ¹H, ³¹P and ¹³C NMR spectroscopy, X‐ray crystallography and elemental microanalysis. Dissolution of H(OEt₂)₂[ 1 ] in acetonitrile results in the slow precipitation of crystalline H(OEt₂)(NCMe)[ 1 ], which was characterized by X‐ray diffraction; however, in CD₂Cl₂ solution the [TRISPHAT]^? anion protonated and ring‐opened. The weighable, solid H(OEt₂)₂ [ 1 ] was found to be a competent initiator for the polymerization of n‐butyl vinyl ether, α‐methylstyrene, styrene and isoprene at a variety of temperatures and monomer‐to‐initiator ratios. At low temperatures, polymers with M_n>10⁵ were obtained for n‐butyl vinyl ether and α‐methylstyrene whereas slightly lower molecular weights were obtained with styrene and isoprene (10⁴<M_n<10⁵). The poly(α‐methylstyrene) synthesized at ?78 °C is syndiotactic‐rich (ca. 87 % rr) whereas the polystyrene obtained at ?50 °C is atactic. The polyisoprene obtained possessed all possible modes of enchainment as well as branched and/or cyclic structures that are often observed in polyisoprene.     

EPR- und Ligandenfeld-Spektren von Chlorovanadaten(IV). Die Kristallstruktur von PPh4[VxTi2–xCl9] (x = 0,15)

E.P.R. and Ligand Field Spectra of Chlorovanadates(IV). The Crystal Structure of PPh₄[V_xTi_2–xCl₉] (x = 0.15) Black, moisture-sensitive crystals of PPh₄[V_xTi_2–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[V_0.15Ti_1.85Cl₉], 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[V_0.15Ti_1.85Cl₉] 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 [V_0.15Ti_1.85Cl₉]^? ions. In the anions, Ti and V atoms are distributed statistically in the two face sharing octahedra.     

Additions- und SubstitutionsReaktionen an Tetrafluor- und Tetrachlordiboran(4)

Addition and Substitution Reactions at Tetrafluoro- and Tetrachlorodiborane(4) From equimolar mixtures of B₂F₄ and Me_nN(SiMe₃)_3-n (n = 0–3) the mono-addition products 1–4 are formed at low temperatures. By elimination of Me₃SiF the adduct 2 gives the dimeric monosubstituted diborane 8 , which slowly decomposes at room temperature to the aminoborane 6 and (BF)_n. The course of the reactions was studied by means of ¹¹B and ¹⁹F NMR spectroscopy and by measuring the vapor pressures. According to the ¹¹B and ³¹P NMR spectra the reaction of B₂Cl₄ with PCl₅ or [Me₄N]Cl in liquid hydrogen chloride at 0°C does not yield [PCl₄]₂⁺[B₂Cl₆]^2? or [Me₄N]₂⁺[B₂Cl₆]^2? but gives [PCl₄]⁺[BCl₄]^?, PCl₃ and BCl₃ or [Me₄N]⁺[BCl₄]^? and BCl₃ besides (BCl)_n.     

Synthese und Struktur von Ammin- und Amidokomplexen des Iridiums

Synthesis and Structure of Ammine and Amido Complexes of Iridium The reaction of (NH₄)₂[IrCl₆] with NH₄Cl at 300 °C in a sealed glass ampoule yields the iridium(III) ammine complex (NH₄)₂[Ir(NH₃)Cl₅], which crystallizes isotypically with K₂[Ir(NH₃)Cl₅] in the orthorhombic space group Pnma with Z = 4, and a = 1350.0(2); b = 1028.5(3); c = 689.6(2) pm. The reaction of (NH₄)₂[IrCl₆] with NH₃ at 300 °C, however, gives the already known [Ir(NH₃)₅Cl]Cl₂ beside a small amount of [Ir(NH₃)₄Cl₂]Cl₂. In pure form [Ir(NH₃)₅Cl]Cl₂ is obtained by ammonolysis of (NH₄)₂[Ir(NH₃)Cl₅] at 300 °C with NH₃. [Ir(NH₃)₄Cl₂]Cl₂ crystallizes triclinic (P1, Z = 1, a = 660,2(3); b = 680,4(3); c = 711,1(2) pm; α = 103,85(2)°, β = 114,54(3)°, γ = 112,75(2)°). The structure contains Cl^– anions and [Ir(NH₃)₄Cl₂]²⁺ cations with a trans position of the Cl atoms. Upon reaction of [Ir(NH₃)₅Cl]Cl₂ with Cl₂ one ammine ligand is eliminated yielding [Ir(NH₃)₄Cl₂]Cl, which is transformed to orthorhombic [Ir(NH₃)₄(OH₂)Cl]Cl₂ (Pnma, Z = 4, a = 1335,1(3); b = 1047,9(2); c = 673,4(2) pm) by crystallization from water. In the octahedral complex [Ir(NH₃)₄(OH₂)Cl]²⁺ the four ammine ligands have an equatorial position, whereas the Cl atom and the aqua ligand are arranged axial. Oxidation of (NH₄)₂[Ir(NH₃)Cl₅] with Cl₂ at 330 °C affords the tetragonal Ir^IV complex (NH₄)[Ir(NH₃)Cl₅] (P4nc, Z = 2, a = 702.68(5); c = 912.89(9) pm). Its structure was determined using the powder diagram. Oxidation of (NH₄)₂[Ir(NH₃)Cl₅] with Br₂ in water, on the other hand, gives (NH₄)₂[IrBr₆] crystallizing in the K₂[PtCl₆] type. Oxidation of (PPh₄)₂[Ir(NH₃)Cl₅] with PhI(OAc)₂ in CH₂Cl₂ affords the Ir^V amido complex (PPh₄)[Ir(NH₂)Cl₅].     

Über die Isolierung von Lithiumhexamethylozirkonat(IV) Li2[Zr(CH3)6]

ZrCl₄ reacts with LiCH₃ at molar ratios 1 :>6 in diethylether/toluene mixtures at about ?40°C to from Li₂[Zr((CH₃)₆]. After removal of the solvents the complex compound can be separated from the ether-free residue by redissolving it in toluene. Evaporation of the toluene at ?23°C yields yellow, crystalline Li₂[Zr(CH₃)₆].     

Building up Strain in One Step: Synthesis of an Edge‐Fused Double Silacyclobutene from an Extensively Trichlorosilylated Butadiene Dianion

The exhaustive trichlorosilylation of hexachloro‐1,3‐butadiene was achieved in one step by using a mixture of Si₂Cl₆ and [nBu₄N]Cl (7:2 equiv) as the silylation reagent. The corresponding butadiene dianion salt [nBu₄N]₂[ 1 ] was isolated in 36 % yield after recrystallization. The negative charges of [ 1 ]^2? are mainly delocalized across its two carbanionic (Cl₃Si)₂C termini (α‐effect of silicon) such that the central bond possesses largely C=C double‐bond character. Upon treatment with 4 equiv of HCl, [ 1 ]^2? is converted into neutral 1,2,3,4‐tetrakis(trichlorosilyl)but‐2‐ene, 3 . The Cl^? acceptor AlCl₃, induces a twofold ring‐closure reaction of [ 1 ]^2? to form a six‐membered bicycle 4 in which two silacyclobutene rings are fused along a shared C=C double bond (84 %). Compound 4 , which was structurally characterized by X‐ray crystallography, undergoes partial ring opening to a monocyclic silacyclobutene 2 in the presence of HCl, but is thermally stable up to at least 180 °C.     

Zwei neue Silicat-Chloride mit zweiwertigem Europium: LiEu3[SiO4]Cl3 und Li7Eu8[SiO4]4Cl7

Two New Silicate-Chlorides with Divalent Europium: LiEu₃[SiO₄]Cl₃ and Li₇Eu₈[SiO₄]₄Cl₇ LiEu₃[SiO₄]Cl₃ was prepared by reaction of LiCl with Eu₂SiO₄ and Li₇Eu₈[SiO₄]₄Cl₇ from Li with Eu₂O₃, SiO₂ and LiCl. The crystal structures of LiEu₃[SiO₄]Cl₃ (Pmna, a = 946.95(13); b = 699.52(8); c = 1 368.0(2) pm; Z = 4; R1 = 0.0325, R2_w = 0.0642) and Li₇Eu₈[SiO₄]₄Cl₇ (P2₁/c; a = 851.85(5); b = 948.62(7); c = 1 679.0(2) pm; β = 96.221(8)°; Z = 2; R1 = 0.0352, R2_w = 0.0744) were determined from four-circle diffractometer data. LiEu₃[SiO₄]Cl₃ contains [Li(SiO₄)₂] units and LiCl₆ octahedra while in Li₇Eu₈[SiO₄]₄Cl₇ larger ?lithosilicate”? groups are found. In both structures, the Eu²⁺ ions are coordinated mostly eightfold by O^2? and Cl^? ligands.     

Chloro- und Polyselenoselenate(II) Darstellung,Struktur und Eigenschaften von [Ph3(C2H4OH)P]2[SeCl4] · MeCN, [Ph4P]2[Se2Cl6] und [Ph4P]2[Se(Se5)2]

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.     

Beiträge zur chemie des iodpentafluorids teil III. Chelatisierung und strukturisomerie bei α,β-methylierten IOD(V)-α,β-ethandiolat-fluoriden

We report metathetical reactions of IF₅ with series of α,β-trimethylsilylated ethanediolates with increasing numbers of CH₃-groups in α- and β-positions. Short lived intermediates IF₄[OC₂H_4?n(CH₃)_nO]X with X = Si(CH₃)₃ or IF₄ and stable chelates IF₃[OC₂H_4?n(CH₃)_nO] and IF[OC₂H_4?n(CH₃)_nO]₂ (n = 0–4) are observed and characterized. Time and temperature dependence of ¹⁹F-NMR-spectra in relation to degree of methylation, arrangement and stereo-chemistry are discussed referring to previously published mono- and polynuclear I(V)-compounds containing a series of monodentate alcoholates CH_3?n(CH₃)_nO^? and (CH₃)₃CCH₂O^? (n = 0,2,3) [1,2] and of bidentate alcoholates ^?O(CH₂)_nO^? (n = 2,3,4,5,6,12) [1]. In contrast to aliphatic α,β-diolates the aromatic diolates 1,2-C₆H₄(O^?)₂, 1,2-C₆Cl₄(O^?)₂ rapidly undergo redox reactions even at low temperatures.     

THERMAL BEHAVIOR AND IONIC CONDUCTIVITY OF POLY[LITHIUM-N(4-SULFO-PHENYL) MALEIMIDE -CO-METHOXY OLIGO(OXYETHYLENE) METHACRYLATE]

Poly[lithium-N(4-sulfophenyl) maleimide -co- methoxy oligo-(oxyethylene) methacrylates] [P(LiSMOE_n)s] with three different oligoether side chains and different salt concentrations were synthesized. The copolyelectrolytes are essentially random in structure, with blocks of methoxy oligo(oxyethylene) meth-acrylate (MOE_nM) recurring sporadically in between the salt units of N(4-sulfophenyl) maleimide. They all show two glass transitions in the temperature range of ?100 to 100°C. The first one below ?30°C is assigned to the oligo(oxyethylene) side chain (T _g1), while the second one located between 20 and 50°C is attributed to the main chain of the polymer host (T _g2). The maximum ionic conductivity of the copolymer electrolytes, 1.6 × 10^?7 S cm^?1 at 25°C, occurs at lithium salt concentration [Li⁺]/[EO] = 2.2 mol%. The ionic conductive behavior of the copolyelectrolytes follows the Vogel-Tammann-Fulcher (VTF) equation. Moreover, a special VTF behavior exists in the copolymers with shorter oligoether side chain and higher salt concentration. Sweep voltammetric results indicate that these copolyelectrolytes have a good electrochemical stability window.     

Cyanidosilicates—Synthesis and Structure

Starting from fluoridosilicate precursors in neat cyanotrimethylsilane, Me₃Si?CN, a series of different ammonium salts [R₃NMe]⁺ (R=Et, ⁿPr, ⁿBu) with the novel [SiF(CN)₅]^2? and [Si(CN)₆]^2? dianions was synthesized in facile, temperature controlled F^?/CN^? exchange reactions. Utilizing decomposable, non‐innocent cations, such as [R₃NH]⁺, it was possible to generate metal salts of the type M₂[Si(CN)₆] (M⁺=Li⁺, K⁺) via neutralization reactions with the corresponding metal hydroxides. The ionic liquid [BMIm]₂[Si(CN)₆] (m.p.=72 °C, BMIm=1‐butyl‐3‐methylimidazolium) was obtained by a salt metathesis reaction. All the synthesized salts could be isolated in good yields and were fully characterized.     

Preparation of Li4Ti5O12 Yolk–Shell Powders by Spray Pyrolysis and their Electrochemical Properties

We have reported for the first time the preparation of yolk–shell‐structured Li₄Ti₅O₁₂ powders for use as anode materials in lithium‐ion batteries. One Li₄Ti₅O₁₂ yolk–shell‐particle powder is directly formed from each droplet containing lithium, titanium, and carbon components inside the hot wall reactor maintained at 900 °C. The precursor Li₄Ti₅O₁₂ yolk–shell‐particle powders, which are directly prepared by spray pyrolysis, have initial discharge and charge capacities of 155 and 122 mA h g^?1, respectively, at a current density of 175 mA g^?1. Post‐treatment of the yolk–shell‐particle powders at temperatures of 700 and 800 °C improves the initial discharge and charge capacities. The initial discharge capacities of the Li₄Ti₅O₁₂ powders with a yolk–shell structure and a dense structure post‐treated at 800 °C are 189 and 168 mA h g^?1, respectively. After 100 cycles, the corresponding capacities are 172 and 152 mA h g^?1, respectively (retentions of 91 and 90 %).     

Magneli phase Ti n O2n − 1 as corrosion-resistant PEM fuel cell catalyst support

Magneli phase titanium suboxide, Ti _n O_{2n ? 1}, with Brunauer–Emmett–Teller surface area up to 25 m² g^?1 was prepared using the heat treatment of titanium oxide (rutile) mixed with polyvinyl alcohol in ratios from 1:3 to 3:1. XRD patterns showed Ti₄O₇ as the major phase formed during the heat treatment process. The Ti _n O_{2n ? 1} showed excellent electrochemical stability in the potential range of ?0.25 to 2.75 V vs. standard hydrogen electrode. The Ti _n O_{2n ? 1} was employed as a polymer electrolyte membrane fuel cell catalyst support to prepare 20 wt% platinum (Pt)/Ti _n O_{2n ? 1} catalyst. A fuel cell membrane electrode assembly was fabricated using the 20 wt% Pt/Ti _n O_{2n ? 1} catalyst, and its performance was evaluated using H₂/O₂ at 80 °C. A current density of 0.125 A?cm^?2 at 0.6 V was obtained at 80 °C.     

Phosphaniminato-Komplexe des Titans. Synthese und Kristallstrukturen von CpTiCl2(NPMe3), [TiCl3(NPMe3)]2, [Ti2Cl5(NPMe2Ph)3] und [Ti3Cl6(NPMe3)5][BPh4]

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.     

Theoretical study on nonlinear optical properties of the Li+[calix[4]pyrrole]Li−dimer,trimer and its polymer with diffuse excess electrons

The static (hyper)polarizabilities of the dimer and trimer with diffuse excess electrons, [Li⁺[calix[4]pyrrole]Li^?]_n, are firstly investigated by the DFT(B3LYP) method in detail. For the dimer and trimer, a Li atom inside each calix[4]pyrrole unit is ionized to form a diffuse excess electron. The results show that the dimer and trimer containing two and three excess electrons, respectively, have very large first hyperpolarizablities as 2.3 × 10⁴ and 4.0 × 10⁴ au, which are 30 and 40 times larger than that of the corresponding [calix[4]pyrrole]_n (n = 2, 3) without Li atom. Also, β values of dimer and trimer are twice and four times as large as that of monomer containing one excess electron. Obviously, not only excess electron but also the number of excess electron plays an important role in increasing the first hyperpolarizability. Moreover, the (hyper)polarizabilities of the [Li⁺[calix[4]pyrrole]Li^?]_n polymer are investigated at ab initio level by using the elongation finite‐field (elongation FF) method. All the oligomers of the [Li⁺[calix[4]pyrrole]Li^?]_n with many excess electrons exhibit very large first hyperpolarizability and large second hyperpolarizability. The present investigation shows that by introducing several and more excess electrons into the nonlinear optical (NLO) materials will be an important strategy for improving their NLO properties, which will be helpful for design of NLO materials. © 2009 Wiley Periodicals, Inc. J Comput Chem, 2010     

Beiträge zur Chemie der Alkylverbindungen von Übergangsmetallen. XL. Über Lithium-alkenylmanganate(II)

Contributions to the Chemistry of Transition Metal Alkyl Compounds. XL. About Lithium Alkenylmanganates(II) MnCl₂ reacts with vinyl, 2,2-dimethylvinyl, allyl, and methallyl lithium giving rise to alkenyl manganates(II). In a pure state the compounds Li₂[Mn(CH?CH₂)₄] · 1.5 diox, Li₂[Mn(CH?C(CH₃)₂)₄] · 1.5 diox, Li₂[Mn(CH₂? CH?CH₂)₄] · 2.5 diox and Li₃[Mn(CH₂? C(CH₃)?CH₂)₅] · 2 diox were isolated. The compounds were characterized by elementary analysis, EPR and IR spectra, magnetic moments, and reactions with iodine.     

Li1.3Al0.3Ti1.7(PO4)3 filler effect on (PEO)LiClO4 solid polymer electrolyte

Composite polymer electrolyte (CPE) films consisting of PEO, LiClO₄, and Li_1.3Al_0.3Ti_1.7(PO₄)₃ with fixed EO/Li = 8 but different relative compositions of the two lithium salts were prepared by the solution casting method. The CPE films were characterized using SEM, DSC, electrical impedance spectroscopy (EIS), and ion transference number measurement. It was found that the incorporation of LiClO₄ and Li_1.3Al_0.3Ti_1.7(PO₄)₃ into PEO by keeping EO/Li = 8 reduced the crystallinity of PEO from 50.34% to the range of 3.57–15.63% depending upon the relative composition of the two salts. The room temperature impedance spectra of the CPE films all exhibited a shape of depressed semicircle in the high frequency range and inclined line in the low frequency range, but the high temperature ones were mainly inclined lines. The Li⁺ ionic conductivity of the CPE films mildly increased and then decreased with increasing Li_1.3Al_0.3Ti_1.7(PO₄)₃ content, and the maximum conductivities were obtained at Li_1.3Al_0.3Ti_1.7(PO₄)₃ content of 15 wt % for all measuring temperatures, for example, 1.378 × 10^?3 S/cm at 100 °C and 1.387 × 10^?5 S/cm at 25 °C. The temperature dependence of the ionic conductivity of the CPE films follows the Vogel–Tamman–Fulcher (VTF) equation The pseudo activation energies (E_a) were rather low, 0.053–0.062 eV, indicating an easy migration of Li⁺ in the amorphous phase dominant PEO. The pre‐exponent constant A and ion transference number t_Li+ were found to have a similar variation tendency with increasing Li_1.3Al_0.3Ti_1.7(PO₄)₃ content and reached their maximums also at Li_1.3Al_0.3Ti_1.7(PO₄)₃ content of 15 wt %. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 743–751, 2005     

Werner Complexes with ω‐Dimethylaminoalkyl Substituted Ethylenediamine Ligands: Bifunctional Hydrogen‐Bond‐Donor Catalysts for Highly Enantioselective Michael Additions

The racemic carbonate complex [Co(en)₂O₂CO]⁺ Cl^? (en=1,2‐ethylenediamine) and (S)‐[H₃NCH((CH₂)_nNHMe₂)CH₂NH₃]³⁺ 3 Cl^? (n=1–4) react (water, charcoal, 100 °C) to give [Co(en)₂((S)‐H₂NCH((CH₂)_nNHMe₂)CH₂NH₂)]⁴⁺ 4 Cl^? ( 3 a – d H⁴⁺ 4 Cl^?) as a mixture of Λ/Δ diastereomers that separate on chiral‐phase Sephadex columns. These are treated with NaOH/Na⁺ BAr_f^? (BAr_f=B(3,5‐C₆H₃(CF₃)₂)₄) to give lipophilic Λ‐ and Δ‐ 3 a–d ³⁺ 3 BAr_f^?, which are screened as catalysts (10 mol %) for additions of dialkyl malonates to nitroalkenes. Optimal results are obtained with Λ‐ 3 c ³⁺ 3 BAr_f^? (CH₂Cl₂, ?35 °C; 98–82 % yields and 99–93 % ee for six β‐arylnitroethenes). The monofunctional catalysts Λ‐ and Δ‐[Co(en)₃]³⁺ 3 BAr_f^? give enantioselectivities of <10 % ee with equal loadings of Et₃N. The crystal structure of Δ‐ 3 a H⁴⁺ 4 Cl^? provides a starting point for speculation regarding transition‐state assemblies.     

Electrochemical behavior of [UO_2Cl_4]~(2-) in 1-ethyl-3-methylimidazolium based ionic liquids

In order to examine the chemical form of uranyl species in 1-ethyl-3-methylimidazolium(EMI) based ionic liquids,UV-visible absorption spectra of solutions prepared by dissolving [EMI] 2 [UO2Cl4] into a mixture of EMICl and EMIBF 4(50:50 mol%) were measured.As a result,it was confirmed that uranyl species in the mixture of EMICl and EMIBF 4 existed as [UO2Cl4]2-.Cyclic voltammograms(CVs) of [UO2Cl4]2-in the mixture were measured at 25 ℃ using a Pt working electrode,a Pt wire counter electrode,and an Ag/Ag + reference electrode(0.01 M AgNO 3,0.1 M tetrabutylammonium perchlorate in acetonitrile) in a glove box under an Ar atmosphere.Peaks corresponding to one redox couple were observed around-1.05 V(Epc) and-0.92 V(Epa) vs.ferrocene/ferrocenium ion(Fc/Fc +).The potential differences between two peaks(Ep) increased from 101 to 152 mV with an increase in the scan rate from 50 to 300 mV s-1,while the(Epc+Epa)/2 value was constant,-0.989 V vs.Fc/Fc + regardless of the scan rate.Furthermore,the diffusion coefficient of [UO2Cl4]2-and the standard rate constant were estimated to be 3.7 × 10-8 cm 2 s-1 and(2.7-2.8) × 10-4 cm s-1 at 25 oC.By using the diffusion coefficient and the standard rate constant,the simulation of CVs was performed based on the reaction,[UO2Cl4]2-+ e = [UO2Cl4]3-.The simulated CVs were found to be consistent with the experimental ones.From these results,it is concluded that [UO2Cl4]2-in the mixture of EMICl and EMIBF 4 is reduced to [UO2Cl4]3-quasi-reversibly at-0.989 V vs.Fc/Fc +.     

Nitrido-Sodalithe. I Synthese,Struktur und Eigenschaften von Zn7–xH2x[P12N24]Cl2 mit 0 ⩽ x ⩽ 3

Nitrido Sodalites. I Synthesis, Crystal Structure, and Properties of Zn_7–xH_2x [P₁₂N₂₄]Cl₂ with 0 ? x ? 3 The nitrido sodalites Zn_7–xH_2x[P₁₂N₂₄]Cl₂ with 0 ? x ? 3 are obtained by heterogeneous pressure-ammonolysis of P₃N₅ at presence of ZnCl₂ (T = 650°C). These compounds are available too by reaction of ZnCl₂, (PNCl₂)₃, and NH₄Cl at 700°C. The crystal structures of four representatives of the above mentioned compounds have been refined by the Rietveld full-profile technique using X-ray powder diffractometer data (I4 3m, a = 821.61(4) to 824.21(1) pm, Z = 1). In the solid a three-dimensional framework of corner-sharing PN₄-tetrahedra occurs (P? N: 163.6 pm, P? N? P: 125.6°, mean values) which is isosteric with the sodalite type of structure. In the center of the β-cages Cl^? ions have been found, which are tetrahedrally coordinated by Zn²⁺ ions. The Zn²⁺ ions are statistically disordered. According to the phase-width observed (0 ? x ? 3) the Zn²⁺ ions may be partially replaced each by two hydrogen atoms which on the other hand are covalently bonded to nitrogen atoms of the P? N framework. The IR-spectra of these compounds show characteristic vibrations.