(PhTe)3−: The Anionic Tellurium Analogue of I3−

The missing link between solid-state tellurium chemistry and polyhalide ions is provided by the synthesis of the almost linear (PhTe)₃⁻ ion, whose structure is shown. Tritelluride units are a recurring motif in the solid state and are related to the structures of polyhalides.     

Spectroelectrochemistry of EuCl3 in Four Molten Salt Eutectics; 3 LiCl−NaCl, 3 LiCl−2 KCl,LiCl−RbCl,and 3 LiCl−2 CsCl; at 873 K

Key electrochemical properties affecting pyroprocessing of nuclear fuel were examined in four eutectic melts using Eu^3+/2+ as a representative probe. We report the electrochemical and spectroelectrochemical behavior of EuCl₃ in four molten salt eutectics (3 LiCl?NaCl, 3 LiCl?2 KCl, LiCl?RbCl and 3 LiCl?2 CsCl) at 873 K. Cyclic voltammetry was used to determine the reduction potential for Eu^3+/2+ and the applied potentials for spectroelectrochemistry. Single step chronoabsorptometry and thin‐layer spectroelectrochemistry were used to obtain the number of electrons transferred, reduction potentials and diffusion coefficients for Eu³⁺ in each eutectic melt. The reduction potentials determined by thin‐layer spectroelectrochemistry were essentially the same as those obtained using cyclic voltammetry. The diffusion coefficient for Eu³⁺ was the largest in the 3 LiCl?NaCl melt, showed a negative shift in the 3 LiCl?2 KCl melt, and was the smallest in the LiCl?RbCl and 3 LiCl?2 CsCl eutectic melts. The basic one‐electron reversible electron transfer for Eu^3+/2+ was not affected by melt composition.     

Darstellung und Konfiguration von Tricarbonylchromat-Anionen mit SnCl3− und GeCl3− als Liganden

B₃N₃Me₆Cr(CO)₃ reacts with [AsPh₄] [SnCl₃] and [AsPh₄] [GeCl₃] in tetrahydrofuran to give [AsPh₄]₃[Cr(CO)₃(SnCl₃)₃] and [AsPh₄]₃[Cr(CO)₃(GeCl₃)₃], respectively. According to IR. and ¹³C-NMR.-data, the tricarbonylate anions possess a meridional configuration. The donor-acceptor properties of SnCl₃^? and GeCl₃^? in the anions [Cr(CO)₃(ECl₃)₃]^3? (E = Sn, Ge) are very similar. A similar synthesis of [AsPh₄]₃[Cr(CO)₃(SnF₃)₃] was not successful.     

Color Point Tuning in Lu3−x−yMnxAl5−xSixO12:yCe3+ for White LEDs

A series of the solid‐solution phosphors Lu_3?x?yMn_xAl_5?xSi_xO₁₂:yCe³⁺ is synthesized by solid‐state reaction. The obtained phosphors possess the garnet structure and exhibit similar excitation properties as the phosphor Lu₃Al₅O₁₂:Ce³⁺, but with an effectively improved red component in the emission spectrum. This can be attributed to the energy transfer from Ce³⁺ to Mn²⁺. Our investigation reveals that electric dipole–quadrupole interactions dominate the energy‐transfer mechanism and that the critical distance determined by the spectral overlap method is about 9.21 Å. The color‐tunable emissions of the Lu_3?x?yMn_xAl_5?xSi_xO₁₂:yCe³⁺ phosphor as a function of Mn₃Al₂Si₃O₁₂ content are realized by continuously shifting the chromaticity coordinates from (0.354, 0.570) to (0.462, 0.494). They indicate that the obtained material may have potential application as a blue radiation‐converting phosphor for white LEDs with high‐quality white light.     

Enantioselective Cross‐Exchange between C−I and C−C σ Bonds

A palladium‐catalyzed enantioselective intramolecular σ‐bond cross‐exchange between C?I and C?C bonds is realized, providing chiral indanones bearing an alkyl iodide group and an all‐carbon quaternary stereocenter. Pd/TADDOL‐derived phosphoramidite is found to be an efficient catalytic system for both C?C bond cleavage and alkyl iodide reductive elimination. In addition to aryl iodides, aryl bromides can also be used for this transformation in the presence of KI. Density‐functional theory (DFT) calculation studies support the ring‐opening of cyclobutanones occuring through an oxidative addition/reductive elimination process involving Pd^IV species.     

Phosphoniumsalze mit Hydrogendihalogenidanionen HCl2−, HBr2− Hl2− oder HBrCl−

Phosphonium Salts with Hydrogen Dihalide Anions HCl₂^?, HBr₂^?, HI₂^?, or HBrCl^? Phosphonium hydrogen dihalides [R₃PR′][XHY] (X = Y = Cl, Br, I; X = Br, Y = Cl) resp. [R₃PH]HBr₂ are obtained as extremely hydrolyzable crystals by reaction of phosphonium halides or tertiary phosphanes with hydrogen halide. According to IR spectroscopic results the solid compounds mostly contain anions [XHX]^? with symmetric hydrogen bonds. In solution ¹H NMR measurements show a slight (X = Cl, Br) or considerable (X = I) dissociation according to HX₂^? ? X^? + HX. On heating the solid compounds decompose with formation of hydrogen halide and [R₃PR′]X or [R₃PH]X. In this process the hydrogen bromidechlorides [R₃PR′][BrHCl] exclusively eliminate HCl. NMR studies (¹H und ³¹P) with solutions containing [R₃PH]HBr₂ (R = phenyl, 1-naphtyl) or HBr and Ph₃P in varying molar ratios show that a fast proton exchange between the competing Lewis bases R₃P and Br^? exists.     

Bromsulfenyl(trihalogen)phosphonium-Salze Cl3−nBrnPSBr+AsF6− (n = 0 – 3) und Cl3PSBr+SbF6− — Oxidative Bromierung von Thiophosphorylhalogeniden

Bromosulfenyl(trihalogeno)phosphonium Salts Cl_3?nBr_nPSBr⁺AsF₆^? (n = 0 – 3) and Cl₃PSBr⁺SbF₆^? — Oxidative Bromination of Thiophosphorylhalides The bromosulfenyl(trihalogeno)phosphonium salts Cl_3?nBr_nPSBr⁺AsF₆^? (n = 0 – 3) and Cl₃PSBr⁺SbF₆^? are prepared by oxidative bromination of the corresponding thiophosphorylhalides with Br₂/MF₅ (M = As, Sb) and characterized by vibrational and NMR spectroscopy.     

Electrochemical Oxidative C−H/N−H Coupling between γ‐Lactams and Anilines

A mild method for the direct C?H/N?H coupling between γ‐lactams and anilines through electrochemical oxidation has been developed. The protocol proceeded smoothly without metal catalysts at room temperature to afford γ‐substituted γ‐lactams in good yields. It has been revealed that the quasi‐divided cell which provided high current density on the anode was crucial for this reaction.     

The heats of formation of NO3− and NO3− association complexes with HNO3 and HBr

The equilibrium constant for the reaction has been determined between 331 and 480°K using a variable-temperature flowing afterglow. These data give ΔH°(1) = -1.03 ± 0.21 kcal/mol and ΔS°(1) = —4.6 ± 1.0 cal/mol°K. When combined with the known thermochemical values for HBr, Br^?, and HNO₃, this yields ΔH(NO₃^?) = -74.81 ± 0.54 kcal/mol and S(NO₃^?) = 59.4 cal/mol·°K. In addition ΔH_n-1,n and ΔS_n-1,nfor the gas-phase reactions were determined for n = 2 and 3. The implications of these measurements to gas-phase negative ion chemistry are discussed.     

Time dependent wave packet treatment of 2ΠgN2− and 3Σ−NO− shape resonances using two‐dimensional surfaces for electron‐N2 and NO interactions

The ²Π_gN and ³Σ^?NO^? resonances in electron‐N₂ and NO collisions have been treated using both nuclear and electronic degrees of freedom and a two‐dimensional (2D) time dependent wave packet approach to ascertain the importance of nonlocality in electron–nuclear interaction. The results so obtained are compared with vibrational excitation cross‐sections obtained experimentally and those from other theoretical/numerical approaches using 1D local complex potential, 2D model with a combination of the exterior complex scaling method and a finite‐element implementation of the discrete‐variable representation. The results obtained provide detailed insight into the nuclear dynamics induced by electron–molecule collision and reveal that while for resonant excitation of lower vibrational modes, the nonlocal effect may not be as critical but importance of nonlocal effects may increase with increase in quanta of resonant vibrational excitation. © 2012 Wiley Periodicals, Inc.     

Atomic integrals containing rrr with λ, μ, ν ≥ −2

In this paper, the efficient evaluation of the atomic integrals I =∫rrrrrre^{?αr1?βr2?γr3}dτ with one or two factors r is described. These integrals are necessary for a lower-bound calculation for Li-like systems using the method of variance minimization or Temple's formula. © 1993 John Wiley & Sons, Inc.     

Die Kristallstrukturen von SeCl3 +SbCl6−, SeBr3+GaBr4−, PCl4+SeCl5− und (PPh4+)2SeCl42− · 2 CH3CN

Crystal Structures of SeCl₃⁺SbCl₆^?, SeBr₃⁺GaBr₄^?, PCl₄⁺SeCl₅^?, and (PPh₄⁺)₂SeCl₄^2? · 2 CH₃CN The crystal structures of the title compounds were determined by X-ray diffraction. SeCl₃⁺SbCl₆^?: Space group P2₁/m, Z = 4, structure determination with 1795 observed unique reflections, R = 0.022. Lattice dimensions at ?80°C: a = 940.9, b = 1066.3, c = 1234.9 pm, β = 102.79°. The compound forms ion pairs with the structure of a double octahedron with linked surfaces. SeBr₃⁺GaBr₄^?: Space group Pc, Z = 2, structure determination with 1461 observed unique reflections, R = 0.058. Lattice dimensions at ?60°C: a = 660.1, b = 655.3, c = 1431.3 pm, β = 101.177°. The compound crystallizes in the SCl₃[AlCl₄] lattice type. Between the ions there are two relatively short Se … Br? Ga contacts. PCl₄⁺SeCl₅^?: Space group Ima2, Z = 8, structure determination with 1757 observed unique reflections, R = 0.029. Lattice dimensions at ?50°C: a = 1651.6, b = 1201.2, c = 1166.4 pm. The SeCl₅^? ions are associated to chains via interionic Se? Cl … Se contacts along the crystallographic c-axis. (PPh₄⁺)₂SeCl₄^2? · 2CH₃CN: Space group P2₁/n, Z = 2, structure determination with 2578 observed unique reflections, R = 0.050. Lattice dimensions at ?80°C: a = 1288.5, b = 726.0, c = 2585.8 pm, β = 101.65°. The compound includes planar-tetragonal SeCl₄^2? ions, which almost meet D_4h symmetry.     

Reversible Silylene Insertion Reactions into Si−H and P−H σ‐Bonds at Room Temperature

Phosphine‐stabilized silylenes react with silanes and a phosphine by silylene insertion into E?H σ‐bonds (E=Si,P) at room temperature to give the corresponding silanes. Of special interest, the process occurs reversibly at room temperature. These results demonstrate that both the oxidative addition (typical reaction for transient silylenes) and the reductive elimination processes can proceed at the silicon center under mild reaction conditions. DFT calculations provide insight into the importance of the coordination of the silicon center to achieve the reductive elimination step.