Bis­(azido‐κN)[(6R,7S,8S,14S)‐(–)‐sparteine‐κ2N,N′]copper(II)

In the title compound, [Cu(N₃)₂(C₁₅H₂₆N₂)], the chiral alkaloid (−)‐l‐sparteine (Sp) acts as a bidentate ligand, with two azide ligands occupying the remaining coordination sites, forming a distorted CuN₄ tetrahedron. The dihedral angle between the N_Sp—Cu—N_Sp and N_azide—Cu—N_azide planes is 55.3 (2)°. Principal dimensions include Cu—N_Sp = 2.011 (6) and 2.025 (5) Å, and Cu—N_azide = 1.939 (6) and 1.934 (7) Å. The mid‐point of the N_Sp⋯N_Sp line does not lie exactly in the N_azide—Cu—N_azide plane, but is tilted towards one of the N_Sp atoms by 0.026 Å.     

Synthesis and properties of poly‐(2‐ethynylpyridinium bromide) having propargyl side chains

Poly‐(2‐ethynylpyridinum bromide) (PEPBP) having propargyl side chains was prepared by the direct polymerization of 2‐ethynylpyridine and propargyl bromide under mild reaction conditions without any initiator and catalysts. The polymerization proceeded well to give PEPBP with propargyl side chains in relatively high yields. Various spectral data for the polymer structure indicated that the conjugated polymer system having N‐propargylpyridinum substituent was formed. This ionic polymer was completely soluble in water, methanol, dimethylformamide, dimethyl sulfoxide, and N,N‐dimethylacetamide and well processable into thin homogeneous film. The photoluminescence intensity (λ_max = 760 nm) of this polymer increased as the temperature was increased. At 1 KHz and room temperature, this polymer has k′ = 2.9 and σ = 7.3 × 10^?10 (S/cm). © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 3151–3158, 2001     

Sandwich-type theorems for multivalent functions associated with the Srivastava-Attiya operator

In the present paper, we investigate some subordination- and superordination-preserving properties for certain classes of analytic and multivalent functions in the open unit disk, which are associated with such multiplier transformations as the Srivastava-Attiya operator. Various sandwich-type theorems for functions belonging to these classes are also obtained.     

Subordination and superordination properties for a class of integral operators

In the present paper, we obtain some subordination- and superordinatiompreserving properties of certain integral operators defined on the space of normalized analytic functions in the open unit disk. The sandwich-type theorems for these integral operators are also considered.     

Tight confinement of semiconductor quantum dots within zeolite by surface silylation

Various MX (M = Cd, Zn, and Mn, X = S and Se) semiconductor quantum dots (QDs) were prepared in zeolite Y. While the QDs are readily expelled from zeolite interior upon exposure of the MX QD-incorporating zeolite Y ([MX]-Y) to the ambient atmosphere due to moisture adsorption, they remain tightly confined within zeolites even after exposure to the moist atmosphere for several weeks when the surfaces were silylated with various silylating agents. This methodology will facilitate the characterization of the zeolite-encapsulated QDs and the application of QD-incorporating zeolites.     

Loss of trace impurities during NAA of liquid reagents

The loss of trace elements during NAA of five liquid reagents, hydrofluoric acid, hydrochloric acid, nitric acid, hydrogen peroxide and deioniyed water, has been investigated using 17 radioactive tracers of⁴⁶Sc,⁵¹Cr,⁵⁴Mn,⁵⁹Fe,⁶⁰Co,⁶⁴⁵Zn,⁷⁵Se,⁸⁵Sr,⁹⁵Zr,¹¹³Sn,¹²⁴Sb,¹⁵¹Eu,¹⁶⁰Yb,¹⁷⁷Lu,¹⁸²Ta,²³³Pa. Two kinds of container quartz and polyethylene have been used for irradiation and also for preconcentration of the reagents. The containers were cleaned before use by washing-leaching-rinsing procedure. The reagents were preconcentrated by subboiling evaporation under the infrared lamp in clean bench. The loss of trace elements has been revealed to be severer for the reagents of hydrochloric acid and nitric acid in the container of quartz than for the other cases, while that is lowest for hydrogen peroxide.     

Di­bromo­[(–)‐sparteine‐κ2N,N′]­zinc(II)

In the title compound, di­bromo­[(6R,7S,8S,14S)‐1,3,4,7,7a,8,9,10,11,13,14,14a‐dodeca­hydro‐7,14‐methano‐2H,6H‐dipyrido­[1,2‐a:1′,2′‐e][1,5]­diazo­cine‐κ²N,N′]­zinc(II), [ZnBr₂(C₁₅H₂₆N₂)], the chiral nitro­gen‐chelating alkaloid (?)‐l ‐sparteine acts as a bidentate ligand, with two bromide ligands occupying the remaining coordination sites, producing a slightly distorted tetrahedral structure. The dihedral angle between the N—Zn—N and Br—Zn—Br planes is 82.4 (1)°. The distortion of the tetrahedral coordination is demonstrated by the fact that the midpoint of the N?N line does not lie in the Br—Zn—Br plane, but is tilted towards one of the N atoms by 0.164 Å. Similarly, the midpoint of the Br?Br line is tilted towards one of the Br atoms by 0.117 Å.     

Precision analysis of Nb−Ti ratio in a superconducting alloy by NAA-PIXE combined technique

A NAA-PIXE combined analysis has been applied to the precise measurement of the concentrations of Nb and Ti in Nb–Ti alloy ingot. The ingot is used in the production of superconductors and the concentration should be controlled very strictly. The ingot cross section could be analyzed with an accuracy of better than 1% by the use of NAA for the preparation of standard samples and PIXE for the nondestructive rapid scan of the surface. The radial and azimuthal concentration profiles of the ingot could be obtained.     

Kinetic separation of propene and propane in metal-organic frameworks: controlling diffusion rates in plate-shaped crystals via tuning of pore apertures and crystallite aspect ratios

A series of isostructural, noncatenated, zinc-pillared-paddlewheel metal-organic framework materials has been synthesized from 1,2,4,5-tetrakis(carboxyphenyl)benzene and trans-1,2-dipyridylethene struts. Substantial kinetic selectivity in the adsorption of propene over propane can be observed, depending on the pore apertures and the rectangular-plate morphology of the crystals.     

Some radius problems related to a certain subclass of analytic functions

For real parameters α and β such that 0≤α1β,we denote by S(α,β) the class of normalized analytic functions which satisfy the following two-sided inequality:αR(zf′(z)/f(z))β,z∈U,where U denotes the open unit disk.We find a sufficient condition for functions to be in the class S(α,β) and solve several radius problems related to other well-known function classes.