Syntheses, Structures and Thermal Stabilities of Three Novel Lanthanide Coordination Polymers with 6-Hydroxynicotinic Acid

Three novel lanthanide coordination polymers {[Ce₂(HOnic)₄(Onic)₂(H₂O)₂]·6H₂O}_n ( 1 ), {[Ln(HOnic)(Onic)‐ (H₂O)₅·(HOnicH)]·H₂O}_n [HOnicH=6‐hydroxynicotinic acid, Ln=Nd ( 2 ), Pr ( 3 )] have been synthesized and characterized by elemental analyses, IR spectrum and single crystal X‐ray diffraction. Structure analyses reveal that 1 features a 2D plane structure while compounds 2 and 3 possess a 1D chain‐like polymeric structure. TG analyses indicate that 1 exhibits higher thermostability than 2 and 3 , which was attributed to the layer polymeric structure of 1 .     

Cu2O-coated polystyrene microsphere materials with enhanced photo- and photoelectro-catalytic activity

Cuprous oxide microsphere material was fabricated by electrochemical deposition using polystyrene particles as template. The samples are characterized by scanning electron microscope (SEM), X-ray diffraction, and UV–vis spectrophotometer. The SEM image shows the morphology and size of the microspheres, and the thickness of covered Cu₂O layer is about 100 nm. Due to the unique microspherical structure, the surface area is larger, and the optical absorption is better in Cu₂O microsphere material than in bulk Cu₂O film, which makes the degradation of methylene blue faster and photoelectrocatalytic oxidation of glucose stronger on Cu₂O microsphere material than on bulk Cu₂O film under visible light illumination. The enhanced photo- and photoelectro-catalytic activity makes the Cu₂O microsphere material more suitable for solar applications.     

穿插和缠绕结构配位聚合物的合成与性能研究

配位聚合物由于具有独特的结构和优异的性能,近年来受到国内外的持续广泛关注,已成为当前化学、物理、材料、医学以及生命科学等领域的热点研究之一,并日益呈现出迅猛发展的良好势头.有关此类化合物的显著特征是:在合成时,其结构中经常发生不同程度的穿插和缠绕现象,使得合成目标化合物的性能产生根本上的改变.因此,本文主要结合本课题组近期的研究工作,评述了穿插和缠绕结构配位聚合物及其相关化合物的合成、结构与气体吸附分离性能应用等方面的研究进展.     

Excited-state proton transfer in 2-(2'-hydroxyphenyl)benzothiazole: formation of the anion in polar solvents

Excited-state proton transfer in 2-(2'-hydroxyphenyl)benzothiazole (HBT) dissolved in pyridine is investigated. New absorptions and fluorescence bands are detected after addition of water or NaOH to the solution. The spectra are identical to the HBT anion absorption and fluorescence. Picosecond spectroscopy is used to determine the kinetics of electronically excited states. The excited-state lifetime of the anion is 3.5 ns. The tautomeric fluorescence of HBT after proton transfer builds up within 4 ps after excitation and decays with a time constant of 20 ps.     

Metallographic and radioisotopic investigation of the plasma nitrided Ti6Al2.5Mo2Cr alloy with an α + β structure

Plasma nitriding of the Ti₆Al_2.5Mo₂Cr alloy was investigated at constant temperatures of 930 °C and 830 °C and at a temperature changing in cycles over the range 930−730 °C. The microstructure of the layer was determined on transverse and inclined microsections. The TiN, Ti₂N and α zones were revealed within the nitrided layer on the inclined microsections. The Ti₂N zone is that which undergoes least etching. The core of the specimen subjected to cyclic nitriding has a structure composed of oval α grains occurring in a matrix of a fine-scale mixture of the α and β phases. The distribution of molybdenum was determined using autoradiography. In the specimen nitrided at 930 °C, a zone with an elevated molybdenum concentration was found to exist below the nitrided layer.     

纳米金属微粒M-Al2O3介孔复合薄膜的光谱特性

用电化学方法合成了纳米金属微粒M(M=Au,Ag,Cu,Co,Ni,CuAg)-Al₂O₃介孔复合薄膜,并研究了其在近紫外至可见光波范围的光谱特性.研究结果表明,复合薄膜的光吸收峰位置与纳米金属微粒和Al₂O₃介孔薄膜的介电常数有关,且随着膜层中纳米金属微粒复合量的增加,大幅度向红外波段移动;通过共沉积的方法形成的合金微粒复合膜也能使吸收边发生移动.同时还发现Ag-Al₂O₃,Au-Al₂O₃介孔复合薄膜分别在波长为360,500nm处存在等离子体共振吸收峰.     

Hydrogen bonded homo- and heterodimers of tetra urea derivatives of calix[4]arenes

Calix[4]arene ethers fixed in the cone conformation and substituted at the upper rim by various urea residues have been synthesized by reaction of the amino calix[4]arenes with isocyanates. Their dimerisation in apolar solvents has been established by the formation of mixed dimers consisting of two different urea derivatives.     

The effect of nitrogen donors on the reactivity of copper(I) aryloxides: Synthesis of thioncarbonates

Significant changes in the reactivity of copper(I) aryloxides are observed in the presence of nitrogen bases leading to an easy method of synthesizing thioncarbonates.     

Preparation and diels-alder reactions of a pyranoid vinyl glycal:model studies for anthraquinone aglycone and carbohydrate syntheses

The preparation of a conjugated pyranoid vinyl glycal is reported, along with several of its thermal [4+2] cycloaddition reactions with a variety of dienophiles. Applications to the anthraquinone antitumor agents are discussed.