Direct coupling of haloquinolines and sulfonyl chlorides leading to sulfonylated quinolines in water

A simple and efficient method has been developed for construction of sulfonylated quinolines via coupling of haloquinolines and sulfonyl chlorides in water. The present methodology provides an attractive approach to various sulfonylated quinolines in moderate to good yields with favorable functional group tolerance, which has the advantages of operation simplicity, readily available starting materials, excellent regioselectivity, scale-up synthesis, and organic solvent-free conditions.     

火焰原子吸收光谱法测定小茴香中的铜、铁、锰和锌

样品在550℃灰化,用王水浸提。用火焰原子吸收法测定样品中的Fe、Cu、Zn、Mn的含量,并对其结果进行了分析。此法校准曲线性关系良好,回收率在94.70%—104.33%。测定结果表明,小茴香中的铁含量较高。     

Mechanical reliability of transparent conducting IZTO film electrodes for flexible panel displays

The mechanical reliability of transparent In-Zn-Sn-O (IZTO) films grown using pulsed DC magnetron sputtering with a single oxide alloyed ceramic target on a transparent polyimide (PI) substrate at room temperature is investigated. All IZTO films deposited at room temperature have an amorphous structure. However, their optical and electrical properties change depending on the oxygen partial pressure applied during depositing process. At an oxygen partial pressure of 3%, the films exhibit a resistivity of 8.3 × 10⁻⁴ Ω cm and an optical transmittance of 86%. Outer bending tests show that the critical bending radius decreases from 10 mm to 7.5 mm when the oxygen partial pressure increases from 1% to 3%. In the inner bending test, the critical bending radius is independent of oxygen partial pressure at 3.5 mm, indicating excellent film flexibility. In the dynamic fatigue test, the electrical resistance of the films reduces by less than 1% for more than 2000 bending cycles. These results suggest that IZTO films have excellent mechanical durability and flexibility in comparison to ITO films.     

Zinc(II) and Mercury(II) Complexes of Pyrazole‐Based NNN‐Type Ligands: Syntheses,X‐ray Structures,Thermal Analyses and DFT Studies

Monomeric zinc(II) and mercury(II) complexes containing tripodal nitrogen donor ligand 2,6‐bis(3,4,5‐trimethyl‐N‐pyrazolyl)pyridine (btmpp) were synthesized, and characterized by elemental and spectroscopic (IR, UV/Vis) analyses, TG‐DTA and single‐crystal X‐ray diffraction studies. X‐ray analyses of the complexes [Zn(btmpp)Cl₂] ( 2 ) and [Hg(btmpp)(SCN)₂] ( 3 ) showed that both structures crystallize in space group P2₁/c with a = 7.9722(6), b = 18.3084(13), c = 13.3117(9) Å and Z = 4 for 2 and a = 8.7830(3), b = 21.1489(7), c = 12.0682(4) Å and Z = 4 for 3 . Both monomeric units contain pentacoordinate metal ions in distorted square‐pyramidal arrangement. The structures of complexes 2 and 3 were also computed with DFT methods at B3LYP/LanL2DZ level and are in good agreement with the experimental values obtained from X‐ray analysis. The NPa charge distributions, HOMO–LUMO gaps, and dipole moments for 1 , 2 , and 3 were also reported. Natural bond orbital analyses were performed to reveal local charges and charge transfers in 1 , 2 , and 3 .     

Synthesis,structure, and base-catalytic performance of a laminar zinc phosphite-phosphate

A two-dimensional zinc phosphite-phosphate [C₃H₆(OH)NH₃][Zn₂(HPO₃)(PO₄)] (1) was hydrothermally synthesized with 2-hydroxypropylammonium cation as the structure-directing agent. This compound has been characterized by single-crystal X-ray diffraction, IR spectroscopy, and powder X-ray diffraction (XRD). Its microporous framework is constructed by ZnO₄, PO₄, and HPO₃ tetrahedral building blocks with 3, 4, and 6-ring channels. With 1 as base catalytic support, the Knoevenagel condensation reaction of benzaldehyde and ethyl cyanoacetate gives a yield of 59%.     

Structural evolvement of ZnO nanoporous films fabricated using prolonged electrodeposition under pulsed voltages

ZnO nanoporous films consisting nanocrystals on ITO-coated glass substrates were prolongedly electrodeposited under pulse voltages in zinc nitrate solution at room temperature. Their structures were found to be determined by experimental parameters, especially, the voltage and the deposition time. On the basis of the structural characterization, the growth mechanism was proposed as a combined growth process: the competitive growth between lateral overgrowth and nanovoid formation. The structural evolvement is believed to be due to the decrease of surface potential with deposition time, leading to the formation of a quasi-two-layer structure. The revealed mechanism here could be helpful to understand the growth and corresponding properties of ZnO films as well as their nanostructures.     

Probing the Metal Composition of Ternary 12–12′‐16 Nanoclusters via Electrospray Ionization Mass Spectrometry

The reaction of [(3,5‐Me₂–C₅H₃N)₂Zn(SeSiMe₃)₂] with a solution of Cd(OAc)₂, Se(Ph)SiMe₃ and PPr₃ at low temperature was used to prepare single crystals of ternary group 12–12′‐16 nanoclusters with the composition [Zn_1.8Cd_8.2Se₄(SePh)₁₂(PPr₃)₄]. A ligand exchange reaction using Na[SePh] was performed to displace the neutral PPr₃ ligands. The resulting clusters were probed using electrospray ionization mass spectrometry to determine the number of zinc and cadmium atoms in the cluster and compared to the all cadmium cluster [Cd₁₀Se₄(SePh)₁₂(PPr₃)₄]. The dianionic clusters [Zn_xCd_10–xSe₄(SePh)₁₄]^2– where x = 0, 1, 2 were assigned in the mass spectra, revealing that the clusters exhibit elemental distributions that are quite narrow in these experiments.     

Direct Determination of Zinc Using Dithizone in Micellar Solution

Abstract

A simple method for direct determination of Zn²⁺ by spectrophotometry using dithizone in micellar solutions is possible. Surfactants are used to overcome the solubility problems of dithizone in aqueous medium. The proposed method saves time and chemicals and is of extremely high sensitivity. Zn²⁺ concentrations of about 2×10^-7 M can be determined. The important analytical parameters and their effects on the reported system are investigated.     

Syntheses,structures and luminescent properties of two Zn(II) complexes of N-2-nitrobenzenesulfonyl-glycine acid

Two luminescent zinc coordination complexes [Zn₂(2-NBS-gly)₄(H₂O)₄]?·?2H₂O (1), and Zn(Im)₂(2-NBS-gly)₂ (2), (2-NBS-glyH?=?N-2-nitrobenzenesulfonyl-glycine acid, Im?=?imidazole) have been synthesized and their crystal structures determined by X-ray crystallography. The Zn(II) in 1 is a five-coordinate geometry and can be described as a slightly distorted square-pyramid; complex 2 is four-coordinate, forming a distorted tetrahedron. Through hydrogen bonding, complex 1 forms a 2-D network and complex 2 forms a zigzag chain. Fluorescent analyses show that both 1 and 2 exhibit photoluminescence in the solid state and may be potential candidates for photoactive materials.