Optical Spin Polarization of a Narrow-Linewidth Electron-Spin Qubit in a Chromophore/Stable-Radical System

Photoexcited organic chromophores appended to stable radicals can serve as qubit and/or qudit candidates for quantum information applications. 1,6,7,12-Tetra-(4-tert-butylphenoxy)-perylene-3,4 : 9,10-bis(dicarboximide) (tpPDI) linked to a partially deuterated α,γ-bisdiphenylene-β-phenylallyl radical (BDPA-d₁₆) was synthesized and characterized by time-resolved optical and electron paramagnetic resonance (EPR) spectroscopies. Photoexcitation of tpPDI-BDPA-d₁₆ results in ultrafast radical-enhanced intersystem crossing to produce a quartet state ( Q ) followed by formation of a spin-polarized doublet ground state ( D ₀). Pulse-EPR experiments confirmed the spin multiplicity of Q and yielded coherence times of T_m=2.1±0.1 μs and 2.8±0.2 μs for Q and D ₀, respectively. BDPA-d₁₆ eliminates the dominant ¹H hyperfine couplings, resulting in a single narrow line for both the Q and D ₀ states, which enhances the spectral resolution needed for good qubit addressability.     

Preparation of inert and high-temperature stable apolar and medium polar glass-capillary columns using OH-terminated polysiloxane stationary phases

Coating intensively leached silica surfaces with OH-terminated phases provides a new way of producing, by simple means, columns with substantially increased inertness and thermostability. In addition, their separation efficiency is found to be typically higher than that of columns with traditional coatings. The underlying basic effect is a condensation process between terminal silanol groups of the phase and residual silanols, of the glass surface, thus producing the mentioned inertness. Moreover, the surface-bonded molecules are immobilized without addition of a radical generator. If required, crosslinking can also be effected using a volatile azo compound. No vinyl groups are required for this additional immobilization process. The paper discusses all processes involved, and gives detailed working directions for the following medium polar phases. OV-1701-OH, OV-31-OH (new, 17% cyanopropyl), OV-61-OH, and OV-17-OH, and the apolar phases PS-347.5 and PS-086. There is no doubt so far that the principle of terminal silanol groups is applicable to all silicone phases, and may replace the traditional endcapped stationary phases in the future.     

Synthese und Strukturanalyse von Na3SbSe3·3Sb2O3·0,5Sb(OH)3

Investigations in the system Sb-Se-NaOH-H₂O, hydrothermal conditions, yielded crystals of the compound Na₃SbSe₃·3Sb₂O₃·0,5Sb(OH)₃. The structure of this compound (a=14.40 Å,c=5.568 Å; space group P 6₃-C ₆ ⁶ ;Z=2) was determined from 985 independent X-ray intensities — collected on an automaticWeissenberg type diffractometer — by thePatterson method and refined by the least squares method toR=8.3% (with -weighting 5.9%). The structure consists of SbO₃ pyramids which are connected via common oxygen corners to tubes parallel [001]. These tubes and SbSe₃ pyramids are combined by Na atoms to a framework. The Sb(OH)₃ groups are statistically located within the channels of the tubes.

     

Viscosity of aqueous NH4Cl and tracer diffusion coefficients of ions,water and non-electrolytes in aqueous NH4Cl,KI, and MgCl2 at 25°C

Viscosities for aqueous NH₄Cl and tracer diffusion coefficients for²²Na⁺,³⁶Cl^–, HTO, and CH₃OH, acetone and dimethylformamide (all¹⁴C-labelled) in NH₄Cl supporting electrolyte are reported for 25°, together with tracer diffusion coefficients for²²Na⁺,³⁶Cl^–, and¹⁴CH₃OH in 1M KI, and for¹⁴CH₃OH in 1M MgCl₂. The diffusion coefficient of HTO in NH₄Cl solutions is slightly larger, for most of the concentration range investigated (0.05 to 4.5 M), than the value for pure water and is almost unaffected by the supporting electrolyte up to about 4M. Similar behavior is shown by CH₃OH, acetone and dimethylformamide in NH₄Cl solutions. Onsager limiting law behavior is approached by Cl^– at NH₄Cl concentrations in the 0.05–0.1M region but at much lower concentrations by Na⁺.     

Die Kristallstruktur von Cu7(OH)6(TeO3)2(SO4)2

The crystal structure of the new phase Cu₇(OH)₆(TeO₃)₂(SO₄)₂ [a=7.389 (1),b=7.638 (1),c=7.662 (2) Å, =75.17 (1), =75.90 (1), =84.19 (1)°;Z=1] was determined by direct methods andFourier summations from X-ray intensities, and was refined in space group P -C _i ¹ toR=0.039. As usual, the Cu(II) atoms are coordinated to four O atoms forming approximately a square with average Cu-O=1.96 (3) Å; one or two more distant O neighbours complete the coordination. The shape of the TeO₃ group is a rather clear-cut trigonal pyramid. A disorder was found for the SO₄ tetrahedra. The compound was synthesized under hydrothermal conditions [500 (10) K, saturation vapour pressure].

Herrn Prof. Dr.K. Komarek zum 60. Geburtstag gewidmet.     

Frequency Measurements of Optically Pumped Laser Emissions from the CHD2OH Methanol Isotope

A threelaser heterodyne system was used to measure the frequencies of eleven optically pumped laser emissions from CHD₂OH in the farinfrared (FIR) region. These frequencies, reported with fractional uncertainties of the order ± 2 × 10^–7, are for emissions ranging from 102.9 to 212.4 m. To our knowledge, these measurements are the first reported FIR laser frequencies for the CHD₂OH methanol isotope when used as an optically pumped laser medium.     

Injectivity and Graded Injectivity

In this paper, we study the injectivity and graded injectivity of modules. Injective testing sets of semiprime Noetherian rings and FBN rings are Particularly investigated. For commutative Artinian Z-graded rings, we prove that gr-injectivity implies injectivity and hence show that the gr-global dimesion and global dimesion are the same.AMS Subject Classification (1991): Primary 18G05, Secondary 18G20, 16P40.     

氧化铝柱层状镧钛酸盐的制备

本文采用分步交换法首次制得了一种新的层柱材料－氧化铝柱层状镧钛酸盐，应用Ｘ射线衍射（ＸＲＤ）、红外光谱（ＩＲ）及透射电子显微镜（ＴＥＭ）等方法对该新材料进行了表征。结果表明，此材料具有较大的层间距（ｄ＝２．０５ｎｍ，６００℃）和较高的热稳定性（＞７００℃），同时考察了合成条件的改变对该材料性能的影响     

Photocatalytic OH radical formation and quantification over TiO2 P25: Producing a robust and optimised screening method

Photocatalytic oxidation of coumarin to 7-hydroxycoumarin was used in order to identify the optimum conditions and the potential limitations of a photocatalytic screening method.     

Benchmarking of DFT functionals for the kinetics and mechanisms of atmospheric addition reactions of OH radicals with phenyl and substituted phenyl‐based organic pollutants

^•OH addition reactions play a pivotal role in the atmospheric transformation of a number of phenyl and substituted phenyl‐based persistent and toxic organic pollutants. Here, we screened appropriate DFT functionals to predict reaction mechanisms and rate constants (k_OH) of the ^•OH additions by taking benzene and substituted benzenes (C₆H₅F, C₆H₅Cl, C₆H₅Br, C₆H₅CH₃, C₆H₅OH) as model compounds. By comparing the k_OH values calculated with DFT methods to experimental values, we found that the ωB97 functional is the best among the 18 functionals considered (using the basis sets 6‐31 + G(d,p) for optimizations and 6‐311++G(3df,2pd) for single point energy calculations) in the temperature range of 230‐330 K. In addition, we found that some other functionals performed well in specific conditions, e.g., BMKD3 is good for benzene, halogenated benzenes and C₆H₅CH₃, and CAM‐B3LYP is good for the reaction of C₆H₅OH at room temperature. Based on the diversity of the electronic structures of the selected model compounds and the frequent occurrence of certain substituents ( CH₃,  OH,  F,  Cl, and  Br) in the target compounds, the functionals recommended here can be used for future study of the reaction mechanisms and k_OH values for ^•OH addition to phenyl and substituted phenyl‐based persistent and toxic organic pollutants.