五种四环类抗生素的固体表面荧光法的研究

五种四环类抗生素的固体表面荧光法的研究解宏智，董川，刘长松，赵丽霞，杜学勤（山西大学化学系，太原，０３０００６）关键词固体表面荧光，碱性降解，四环类抗生素四环类抗生素的亲癌作用使其成为诊断和治疗肿瘤的荧光探针［１］，基于该类抗生素碱性降解速率的差异［...     

单分散α-Fe_2O_3纳米结构空心亚微球的制备及表征

采用一种新的溶液生长法结合多步包覆法在自制的不同粒径SiO2单分散亚微球表面包覆不同厚度的β-FeOOH涂层,得到单分散β-FeOOH/SiO2核壳结构亚微球.实验结果表明,SiO2核心颗粒尺寸对表面涂层的形态和包覆均匀性有很大影响.当SiO2核心颗粒的平均粒径为250 nm左右时,β-FeOOH表面涂层均匀,颗粒间团聚较少,一次包覆后涂层厚度约为35 nm.涂层中β-FeOOH纳米棒的尺寸随着所选SiO2核心颗粒粒径的增大而相应增大.经多次包覆能够显著提高涂层的厚度,3次包覆后β-FeOOH表面涂层厚约100 nm.β-FeOOH/SiO2核壳结构亚微球与质量分数5%的NaOH溶液反应后,于600℃焙烧2 h得到了单分散α-Fe2O3空心微球.单分散α-Fe2O3空心亚微球表层是由α-Fe2O3纳米棒搭建而成的三维网络结构,α-Fe2O3纳米棒的尺寸与核壳结构中β-FeOOH纳米棒的尺寸基本一致.     

含磷芳基肟胺衍生物的合成及其生物活性

通过硫代磷酰氯和硫代磷酰基异硫氰酸酯与芳基肟胺化合物的反应合成了１９个新的芳基肟胺衍生物，并确证了其结构。初步生物活性测试表明它们具有一定杀菌活性。     

二氯化锰慢性染毒对大鼠脏器和血液元素含量的影响

用ＭｎＣｌ２水溶液通过气管和腹腔二条途径对Ｗｉｓｔａｒ大鼠染毒，气管染毒４个月，总量达（７４．４９～１８．５９）×１０－６，腹腔染毒４个月，总量达（１１４５．２６～５７２，４）×１０－６．采用原子吸收光谱法，测定了大鼠肝、脾、肺、肾、脑和血液中锰、钙、镁元素的含量．结果：脑、肺组织中锰元素含量显著高于对照组（Ｐ＜０．０５和Ｐ＜０．０１），脾脏钙元素和血液镁元素含量显著低于对照组（Ｐ＜０．０５和Ｐ＜０．０１）．提示：慢性锰中毒对脏器与血液中元素含量的影响不可忽视．     

Nickel(II) and palladium(II) thiaethyneporphyrins. Intramolecular metal(II)-η2-CC interaction inside a porphyrinoid frame

3,18-Diphenyl-8,13-di-p-tolyl-20-thiaethyneporphyrin ([18]thiatriphyrin(4.1.1)), which formally contains an C1-C2 ethyne moiety instead of pyrrole embedded in the macrocyclic framework of 21-thiaporphyrin, was obtained in a modification of the "3 + 1" approach using the ethyne analogue of tripyrrane (1,4-diphenyl-1,4-di(pyrrol-2-yl)but-2-yne) and 2,5-bis(p-tolylhydroxymethyl)thiophene. The spectroscopic and structural properties of 20-thiaethyneporphyrin reflect its macrocyclic aromaticity, revealing a combination of the acetylene (≥C-C≡C-C≤) and cumulene (>C═C═C═C<) character of the C18-C1-C2-C3 linker. The magnetic manifestations of aromaticity and antiaromaticity of thiaethyneporphyrin and its two-electron-oxidized derivative were observed using (1)H NMR spectroscopy and were confirmed by density functional theory calculations involving chemical shifts and nucleus-independent chemical shift analysis. Protonation of 20-thiaethyneporphyrin yielded a nonaromatic tautomer of iso-20-thiaethyneporphyrin, locating the saturated meso carbon adjacent to thiophene. Insertion of palladium(II) and nickel(II) into 20-thiaethyneporphyrin afforded planar palladium(II) thiaethyneporphyrin and low-spin diamagnetic nickel(II) 20-thiaethyneporphyrin as determined by X-ray crystallography. 20-Thiaethyneporphyrin acts as a dianionic ligand that coordinates through the two nitrogen and one sulfur donors. Metal(II) ions are uniquely exposed to form an intramolecular metal(II)-η(2)-CC bond, whereas the organometallic fragment is coplanar with the whole macrocycle. Coordination of pyridine converts diamagnetic nickel(II) thiaethyneporphyrin into its paramagnetic counterpart as determined by (1)H NMR.     

SO2存在条件下M/REY催化剂NH3选择性还原NO性能研究

采用浸渍法制备了以REY为载体负载金属氧化物催化剂。采用XRD、NH₃-TPD、NO-TPD、H₂-TPR和XPS对催化剂进行表征,并在固定床微型反应器上评价SO₂存在条件下催化剂在NH₃选择还原NO反应中的活性。实验结果表明,活性组分种类及负载量均影响催化剂性能,Cu(3)/REY催化剂在NH₃选择还原NO反应中表现出较好的低温活性,在SO₂存在条件下,254~390℃时NO的转化率大于95%。催化剂表征结果显示,Cu(3)/REY催化剂的催化活性与其良好的氧化还原性和对NO的吸脱附性能相关。     

铥、镱共掺杂纳米二氧化钛/硫化镉光催化降解甲基橙的研究

采用溶胶-凝胶法制备出稀土离子Tm3+和Yb3+共掺杂的纳米TiO2/CdS复合光催化剂,采用XRD、UV-Vis吸收光谱、TEM及上转换发光光谱等对其结构和光学特性进行了表征,以染料甲基橙为降解模型,系统地讨论了溶液的pH值、催化剂投加量、溶液初始浓度、光照强度等对复合催化剂光催化性能的影响,并对光催化降解动力学进行了分析.     

Effect of high pressure on the organocatalytic asymmetric Michael reaction: highly enantioselective synthesis of γ-nitroketones with quaternary stereogenic centers

The significant effect of hydrostatic pressure on the difficult organocatalytic 1,4-conjugate addition of nitroalkanes to prochiral sterically congested β,β-disubstituted enones is demonstrated. This approach allows for the synthesis of γ-nitroketones containing quaternary stereogenic centers with good yields, excellent enantioselectivity, and low loading (1-5 mol %) of simple chiral primary amine catalysts.     

链解缠结聚对苯二甲酸乙二酯的结晶行为研究

采用冷冻萃取聚对苯二甲酸乙二酯(PET)溶液(0.1～10g/dL7种不同浓度,3种不同性能溶剂)的方法制备了解缠结PET试样.与链相互穿透且缠结的熔体骤冷试样相比,解缠结PET试样的结晶能力明显增强,且随着制样溶液浓度的降低,链间解缠结程度增加,PET的结晶能力逐渐增强,有序结构含量明显增加,但是如果制样溶液浓度太低,溶液中链间距离太大,则又不利于萃取过程中链间的有序堆砌而结晶.采用接触浓度c*附近的溶液,既可确保链间的有效解缠结又有利于链间的有序堆砌而结晶.PET的结晶能力甚至还受制样所用溶剂性能的影响,这是因为溶剂性能影响了溶液中链间的相互作用以及链的解缠结程度.     

链解缠结后聚合物的结晶行为

就近年来关于高分子链解缠结及其对聚合物结晶行为的影响研究作了较为详细的介绍,阐明链解缠结后由于高分子的运动不受或很少受到周围分子的限制,聚合物的结晶能力是增强的,并对可能影响链解缠结程度以及结晶的多种因素(制样溶液浓度、溶剂性能、溶剂尺寸等)进行了讨论.