糖肽的合成

综述了Ｎ－和Ｏ－及其它糖肽苷键的形成和糖肽的合成，包括直接缩合法和基元合成法，此外还着重介绍了糖肽中的各种保护基。     

全有机S型异质结PDI-Ala/S-C3N4光催化剂增强光催化性能

Organic photocatalysts have attracted attention owing to their suitable redox band positions, low cost, high chemical stability, and good tunability of their framework and electronic structure. As a novel organic photocatalyst, PDI-Ala (N, N'-bis(propionic acid)-perylene-3, 4, 9, 10-tetracarboxylic diimide) has strong visible-light response, low valence band position, and strong oxidation ability. However, the low photogenerated charge transfer rate and high carrier recombination rate limit its application. Due to the aromatic heterocyclic structure of g-C₃N₄ and large delocalized π bond in the planar structure of PDI-Ala, g-C₃N₄ and PDI-Ala can be tightly combined through π–π interactions and N―C bond. The band structure of sulfur-doped g-C₃N₄ (S-C₃N₄) matched well with PDI-Ala than that with g-C₃N₄. The electron delocalization effect, internal electric field, and newly formed chemical bond jointly promote the separation and migration of photogenerated carriers between PDI-Ala and S-C₃N₄. To this end, a novel step-scheme (S-scheme) heterojunction photocatalyst comprising organic semiconductor PDI-Ala and S-C₃N₄ was prepared by an in situ self-assembly strategy. Meanwhile, PDI-Ala was self-assembled by transverse hydrogen bonding and longitudinal π–π stacking. The crystal structure, morphology, valency, optical properties, stability, and energy band structure of the PDI-Ala/S-C₃N₄ photocatalysts were systematically analyzed and studied by various characterization methods such as X-ray diffraction, transmission electron microscopy, energy dispersive X-ray spectrometry, X-ray photoelectron spectroscopy, ultraviolet visible diffuse reflectance spectroscopy, electrochemical impedance spectroscopy, and Mott-Schottky curve. The work functions and interface coupling characteristics were determined using density functional theory. The photocatalytic activities of the synthesized photocatalyst for H₂O₂ production and the degradation of tetracycline (TC) and p-nitrophenol (PNP) under visible-light irradiation are discussed. The PDI-Ala/S-C₃N₄ S-scheme heterojunction with band matching and tight interface bonding accelerates the intermolecular electron transfer and broadens the visible-light response range of the heterojunction. In addition, in the processes of the PDI-Ala/S-C₃N₄ photocatalytic degradation reaction, a variety of active species (h⁺, ·O₂^-, and H₂O₂) were produced and accumulated. Therefore, the PDI-Ala/S-C₃N₄ heterojunction exhibited enhanced photocatalytic performance in the degradation of TC, PNP, and H₂O₂ production. Under visible-light irradiation, the optimum 30%PDI-Ala/S-C₃N₄ removed 90% of TC within 90 min. In addition, 30%PDI-Ala/S-C₃N₄ displayed the highest H₂O₂ evolution rate of 28.3 μmol·h^-1·g^-1, which was 2.9 and 1.6 times higher than those of PDI-Ala and S-C₃N₄, respectively. These results reveal that the all organic photocatalyst comprising PDI-based supramolecular and S-C₃N₄ can be efficiently applied for the degradation of organic pollutants and production of H₂O₂. This work not only provides a novel strategy for the design of all organic S-scheme heterojunctions but also provides a new insight and reference for understanding the structure–activity relationship of heterostructure catalysts with effective interface bonding.      

伯胺N1923、三苯基氧化膦的界面吸附特性

在25±1℃下考察了N_(1923)(或TPHPO)-CHCl_3/HCl(或HCl-AuCl_4)和N_(1923)-TPhPO-CHCl_3/HCl(或HCl-AuCl_4~-)等6个体系的界面吸附特性,得到了各体系C_(min)、Γ_∞、A_1等界面吸附特性参数。结果表明,N_(1923)的界面活性明显强于TPhPO.当N_(1923)-TPhPO共存时的Γ_∞值较之N_(1923)或TPhPO单独存在时均有增加,可用于解释萃取动力学行为。     

N-TiO2/ZnO复合纳米管阵列的掺杂机理及其光催化活性

以ZnO纳米柱阵列为模板, 采用溶胶-凝胶法制备出TiO2/ZnO和N掺杂TiO2/ZnO的复合纳米管阵列. 扫描电镜(SEM)、X射线光电子能谱(XPS)和紫外-可见漫反射吸收光谱(UV-Vis)的结果表明: 两种阵列的纳米管均为六角形结构, 直径约为100 nm, 壁厚约为20 nm; 在N-TiO2/ZnO复合纳米管阵列中, 掺入的N离子主要是以N-Ox、N-C和N-N的形式化学吸附在纳米管表面, 仅有少量的N离子以取代式掺杂的方式占据TiO2晶格O的位置; 表面N物种形成的表面态能级和取代式掺杂导致带隙的窄化, 增强了纳米管阵列的光吸收效率, 促进了光生载流子的分离. 光催化实验结果表明, N离子的掺杂有利于N-TiO2/ZnO复合纳米管阵列光催化活性的提高.     

New Synthesis and Molecular Structure of 2-(4'-Methoxyphenyl)-2,4-dithia-1,3,2-diazaphospholidine-5,1'-spirocyclohexane

1 INTRODUCTION Our continuous efforts to look for biologically active heterocyclic compounds led to a new and efficient synthesis of phosphoroheterocycles 1, 3, 2-diazaphospholidine-4-thione 2-sulfides in good yields by the treatment of Lawesson磗 reagent with various -aminonitriles in one-pot procedure. Many approaches to synthesize such phosphoroheterocycles have been reported[1~4]. The common pathways leading to 1, 3, 2-diazaphospho- lidine-4-thione(one) 2-sulfide(oxide) are using t…     

3－苯基－5－取代苯氨基－6－甲基－1，2，4－三嗪的合成

３－苯基－５－取代苯氨基－６－甲基－１，２，４－三嗪的合成陆忠娥，曾润生，席海涛（苏州大学化学系，苏州，２１５００６）关键词硫代苯甲酰胺，α－乙酰基硫代甲酰苯胺，Ｎ＇－氨基苯甲脒，３－苯基－５－取代苯氨基－６－甲基－１，２，４－三嗪１，２，４－三嗪类...     

酚醛型吸附树脂在非水体系中对吡啶和N,N-二甲基苯胺的吸附性能研究

研究了酚醛型吸附树脂JDW 2在非水体系中对吡啶和N ,N 二甲基苯胺的静态吸附 .由实验结果推论正己烷中树脂对吡啶和N ,N 二甲基苯胺的吸附是以氢键吸附机理为主进行的 ,JDW 2酚醛型吸附树脂在正己烷中 ,等温吸附吡啶和N ,N 二甲基苯胺的平衡吸附数据符合Langmuir方程 ,相关系数在 0 99以上 ,因此 ,酚醛型吸附树脂在正己烷中吸附吡啶和N ,N 二甲基苯胺属单分子层吸附 ;同时对非水体系中乙醇或乙酸乙酯的含量对树脂吸附吡啶和N ,N 二甲基苯胺的影响进行了研究     

Synthesis and Crystal Structure of Drum Organooxotin Clusters from Heteroaromatic Carboxylic Acid [PhCH2Sn（O）（O2CC5H4N）]6 and[PhCh2Sn）（O）（O2CC4H3O）]6

IntroductionRecentlywehaveinvestigatedthestructuralchemistryofanumberofdi ortri organotinheteroaromaticcarboxyl ates.1 5Thesestudieshaveshownthatthestructureoforgan otinheteroaromaticcarboxylatesisdependentonboththena tureofthealkylorarylsubstituentboundtothetinatomandthetypeofcarboxylateligand .Inparticular,majorstructuralvariationsareobservedwhencarboxylateligandcontainsanadditionaldonoratom ,suchasapyridineNatom ,availableforcoordinationtotheSnatom .1 3,5 8Wehavenowturnedtothemonoorganotin…     

Pt、N共掺杂TiO2在可见光下对三氯乙酸的催化降解作用

采用溶胶-凝胶法制备了氮掺杂纳米TiO₂(N-TiO₂), 并用光分解沉积法在N-TiO₂表面负载微量金属Pt(0.5％(w)), 形成铂-氮共掺杂纳米TiO₂(Pt/N-TiO₂). 实验结果表明, Pt 、N共掺杂纳米TiO₂紫外可见光吸收边带较纳米TiO₂红移约20 nm, 并在400～500 nm处有弱的吸收. Pt/N-TiO₂电极在可见光区的光电流约为纳米TiO₂电极的6倍. 以Pt/N-TiO₂为催化剂, 催化三氯乙酸(TCA)光降解反应, 室温下经可见光照射2 h后TCA降解率约为8％. N掺杂减小了TiO₂的禁带能隙, 使它在可见光区具有光催化活性, 适量Pt掺杂抑制了光生载流子的复合, 加速了电子界面传递速度, Pt、N共掺杂使两种效应相结合, 进一步提高了光催化反应性能.