偶氮苯水杨醛缩氨基芴席夫碱的合成与表征

以苯胺和取代苯胺为原料,经重氮化、亲电取代以及缩合反应,设计合成了4种新型结构的偶氮苯水杨醛缩氨基芴席夫碱。经乙醇重结晶,以高达87.2%的产率得到目标产物,并利用~1HNMR、~(13)CNMR、红外光谱和元素分析对目标化合物的结构进行表征。     

2-(取代乙炔基)苯甲醛衍生物在有机合成中的应用

作为一类具有特殊结构的重要有机合成中间体，2-(取代乙炔基)苯甲醛衍生物的化学结构是由苯环、取代乙炔基和醛基三部分活性基团构成的共轭体系. 因其具有较高的反应活性，而被广泛的用于构建各种具有新颖结构的苯并碳环或苯并杂环类化合物，如苯并碳环化合物、苯并氮杂环化合物、苯并氧杂环化合物、多元苯并杂环化合物等. 本文综述了2-(取代乙炔基)苯甲醛衍生物在有机合成领域的应用，并对其发展前景进行了展望，为今后2-(取代乙炔基)苯甲醛衍生物在有机合成中的应用提供参考.     

唑、嗪和呋咱类富氮化合物热行为研究进展

综述了近年来国内外关于唑、嗪和呋咱类富氮化合物热行为的研究进展,分析总结了热行为研究的方法,得出了化合物结构和取代基团对化合物热稳定性的影响规律。研究表明,富氮化合物热稳定顺序为:呋咱类嗪类唑类;三唑四唑五唑;三嗪四嗪,这是由于含碳量、骨架张力和共平面等因素引起的。引入硝基、偶氮键、氰基和叠氮基等含氮基团会降低热稳定性,这是由于取代基团的吸电子效应引起的。富氮环之间的共轭效应可以有效增强分子化合物的热稳定性。指出将热分析与理论计算及气相色谱结合来推断反应机理是未来相关研究的一个方向。     

苯系蓝色偶氮染料的合成与光谱特性

关于苯系蓝色偶氮染料的制备和光谱性能缺少总结性的叙述,并且在已发表的关于偶氮染料吸收峰值计算中,蓝色染料的实验性资料也是很少的。下面我们根据单一化合物Ⅰa-s、Ⅱa-x和Ⅱa-j叙述偶氮染料Ⅰ～Ⅲ的合成及其紫外可见光谱性能。我们用通常的方法将强吸电子取代的重氮组分与给电子化合物偶合,或在邻卤基偶氮苯Ⅰ上进行卤素交换,制备了这些化合物。     

芳香间隔基Gemini型席夫碱化合物的合成及表征

以溴代十六烷、2,4-二羟基苯甲醛、苯胺、对苯二胺、联苯二胺为原料,经醚化和席夫碱反应合成中间体和新颖的具有芳香间隔基Gemini型席夫碱化合物以及相应的单体化合物。通过核磁共振、元素分析等对化合物的结构进行表征。利用紫外光谱和红外光谱研究了目标产物的间隔基效应和酸致变色性能。结果表明,随间隔基的变化,席夫碱衍生物的光谱性质发生了明显的变化。由于在溶液与浇铸膜中组装模式的不同,化合物的酸致变色的程度表现出明显的差异,具有广阔的应用前景。     

新型羟基苯基苯并咪唑类衍生物的合成及其光谱性质研究

合成了8个具有不同结构的羟基苯基苯并咪唑类荧光化合物,通过1 H NMR,IR对其进行了结构表征,并研究了它们在甲醇溶液中的光谱性质及取代基对光谱性质的影响。该类化合物的荧光量子产率在0.006～0.75之间,Stokes位移大(>117nm)。实验结果表明,化合物上所连取代基的性质对其光谱有显著影响,具有推电子基团的羟基苯基苯并咪唑类化合物在光激发下出现荧光双发射峰,而具有吸电子基团的化合物在光激发下仅出现激发态质子转移荧光发射峰,表现出Stokes位移大和荧光量子产率高的优点。     

Mills缩合反应制备不对称偶氮苯酚化合物的研究

以苯酚和芳胺为原料分两步合成了四种偶氮化合物。首先由苯酚直接亚硝化的方法来制备对亚硝基苯酚,再与芳胺(苯胺、对苯二胺、邻苯二胺、邻氨基乙酰苯胺)通过缩合反应制备了系列偶氮苯酚,分别为4-羟基偶氮苯、4-氨基-4′-羟基偶氮苯、2-氨基-4′-羟基偶氮苯、2-乙酰氨基-4′-羟基偶氮苯。通过比较这四个化合物的制备条件和产率,考察了酚羟基、氨基等取代基对Mills反应的影响。     

一些苯系偶氮型分散染料的光谱及染色性能

本文合成了三个系列15个橙及红色苯系偶氮型分散染料,讨论了取代基对吸收光谱、染色性能的影响,发现其光谱性能受重氮组份和偶合组份上取代基性质的影响,而其上色性能则主要由偶合组份上端氨基取代基的性质所决定。     

烷基三唑硫酮席夫碱的合成和生物活性研究

为进一步研究三唑席夫碱化合物的合成与性质,以自制的5-烷基-4-氨基-1,2,4-三唑-3-硫酮与对甲氧基苯乙酮和取代芳醛为原料,在冰醋酸催化下,回流反应0.5 h,合成了1,2,4-三唑硫酮席夫碱化合物,其结构通过元素分析、红外光谱(IR)和核磁共振(1H NMR)进行表征。分析结果表明:在IR图谱中,目标产物在波数1 587—1 603 cm-l处出现席夫碱亚胺结构CHN的特征吸收峰;在1H NMR中,席夫碱亚胺结构CHN的质子化学位移δ在10.5附近出现,NC—CH3结构中H的化学位移在2.4左右。研究了化合物对烟草赤星病、马铃薯干腐病、小麦赤霉病、番茄早疫病、西瓜枯萎病5种植物病原菌的生物活性,得到毒力回归方程及相关系数,计算EC50和EC95值,结果表明它们具有较好的抑菌活性。含有吸电子取代基的席夫碱杀菌效果比给电子取代基的好。     

新不对称含膦(胂)酸基变色酸双偶氮衍生物的合成及其与稀土元素显色反应的研究

通过将各种取代基引至变色酸双偶氮衍生物不含成盐基团一侧的偶氮苯的邻、间或对位上,合成了一系列新的不对称含膦(胂)酸基变色酸双偶氮衍生物。这些化合物是偶氮胂 DBM、偶氮胂DBEO、偶氮氯膦 DBM 和对三氟甲基偶氮氯膦等。单取代的试剂与稀土的配合物具有两个吸收峰,分别在610～620 nm 和660～670 nm,而多取代试剂与稀土配合物的吸收峰是630～645 nm。配合物摩尔吸收系数大于或等于10(?)。     

Fractionation and analysis of fluorescent products of lipid peroxidation

The fluorescence excitation spectrum of model conjugated Schiff base compounds that arise from the reaction of malonaldehyde with amino acids was shown to contain a maximum at 260–280 nm in addition to the previously observed maximum at 350–390 nm. Excitation at either maximum results in emission at a single maximum at 440–480 nm. The excitation and emission maxima of the model fluorescent compounds, together with the characteristic reductions in fluorescence intensity caused by alkaline pH or heavy metal coordination, provide criteria with which to examine lipid peroxidation products for the presence of the conjugated Schiff base fluorophore. Silicic acid column chromatography and silica gel thin layer chromatography were employed to fractionate the fluorescent products of model lipid peroxidation systems and of rat testicular lipid soluble extracts. These products contained large families of compounds whose fluorescence characteristics were the same as those of the Schiff base floorophores. The fractionation methods used enabled more thorough fluorescence characterization of many of the products of lipid peroxidation, but the fluores-cence criteria available do not provide definitive proof of structure.     

一种新型共轭Schiff碱聚合物的合成与表征

以对苯二甲醛和水合肼为原料,无水乙醇作溶剂合成了一种共轭Schiff碱聚合物,并通过GPC、IR、1 H NMR、紫外-可见吸收光谱和荧光光谱对其分子量和组成结构进行表征。结果表明,该物质为一种分子量较大的共轭Schiff碱聚合物,具有良好的荧光性。     

Empirical and theoretical investigations on the corrosion inhibition characteristics of mild steel by three new Schiff base derivatives

Synthesis, adsorption and corrosion inhibiting effect of three new Schiff base compounds on mild steel in 1.0?M HCl were explored using weight loss, electrochemical impedance spectroscopy (EIS), and potentiodynamic polarization techniques. The empirical results showed that three Schiff base compounds inhibited the corrosion reaction in aggressive acid medium. Impedance results indicate that the three organic compounds were adsorbed on the mild steel/solution interface, while polarization data show that the three compounds performed typically as a mixed-type inhibitor. A theoretical study of the adsorption performance of some of the components of Schiff base inhibitors was carried out in the basis of the density functional theory (DFT) and Monte Carlo simulations.     

含邻氨基苯甲酸新型三核席夫碱化合物的合成与表征

以邻氨基苯甲酸、3-羧基水杨醛、乙酸铜和乙酸锌为原料合成了新型Cu2+、Zn2+三核席夫碱配合物。以氯仿和无水乙醇做溶剂,在pH7~8的条件下顺利合成得到了新型Cu2+、Zn2+三核席夫碱配合物,并对它们的合成条件分别进行了探索性实验,确定了合成它们的各自优化条件。产品通过元素分析1、H NMRI、R、UV和MS进行组成和结构表征。     

Low band gap Schiff base polymers obtained by complexation with Lewis acids

Two Schiff base polymers were prepared from the respective monomers by condensation method using toluene and N-methyl-2-pyrrolidinone as solvent. They were complexed with Al(III), In(III), and Cu(II) trifluoromethane sulfonates (triflates), and AlCl₃ Lewis acids and characterized by FT-IR, UV–Vis spectroscopy, and scanning electron microscopy (SEM). Homogeneous films were prepared by spin coating in the presence and absence of Lewis acids. Polymer–Lewis acid interaction was confirmed by FT-IR, UV–Vis spectroscopy, and SEM. Lewis acid composition in polymers was determined by FT-IR spectroscopy. Absorption spectra of these conjugated Schiff base polymer complexes exhibited smaller optical band gap than pristine polymers. These variations ranged from 2.4 to 1.4 and 3.3 to 2.0 eV. Absorption depends on the Lewis acid in the polymer and band gap on the nature of the metal incorporated in the polymeric backbone. Solubility increased by complexation. The obtained complexes were soluble in trifluoroacetic and formic acids and in m-cresol. Polymer–Lewis acid solutions in m-cresol were stable for 98 h; the others remained stable over several months. The results of this study revealed that optical, solubility, and band-gap properties of conjugated Schiff base polymers can be modified by Lewis acids and these could be studied by optoelectronics.     

Synthesis,Biological Study and Complexation Behavior of Some Anionic Schiff Base Amphiphiles

A novel series of anionic Schiff base amphiphiles were synthesized. The chemical structures of these compounds were elucidated using different spectroscopic tools. The surface and thermodynamic properties of the prepared Schiff bases were studied using classical measurements including surface and interfacial tensions. The surface parameters of these compounds, e.g., surface tension, critical micelle concentration, effectiveness, efficiency, maximum surface excess, minimum surface area, and interfacial activity showed their good surface activity. Their thermodynamic parameters of adsorption and micellization including free energy change of micellization and adsorption showed their tendency toward adsorption at the interfaces and also micelle formation at lower concentrations. The complexation behavior of the synthesized Schiff bases were study through the interaction of the Schiff base (IIIa; SBSD) with nickel chloride hexahydrate. All synthesized compounds in addition to NiCl₂·6H₂O and Ni Schiff Base complex have been evaluated for their antibacterial activity against Gram-positive and Gram-negative bacteria. The results of the biocidal activities showed high potent action of (Ni-III_a; Ni-SBSD) complex more than Schiff base IIIa; SBSD.     

Adhesion inhibition of F1C-fimbriated Escherichia coli and Pseudomonas aeruginosa PAK and PAO by multivalent carbohydrate ligands

In order to evaluate their inhibition of bacterial adhesion, the carbohydrate sequences GalNAcbeta1-->4Gal and GalNAcbeta1-->4Galbeta1-->4Glc were synthesized. The disaccharide was conjugated to dendrons based on the 3,5-di-(2-aminoethoxy)-benzoic acid branching unit to yield di- and tetravalent versions of these compounds. A divalent compound was also prepared that had significantly longer spacer arms. Relevant monovalent compounds were prepared for comparison. Their anti-adhesion properties against F1C-fimbriated uropathogenic Escherichia coli were evaluated in an ELISA-type assay by using a recombinant strain and also by using Pseudomonas aeruginosa strains PAO and PAK. Adhesion inhibition was observed in all cases, and multivalency effects of up to one order of magnitude were observed. The combination of spacer and multivalency effects led to a 38-fold increase in the potency of a divalent inhibitor with long spacer arms towards the PAO strain when compared with the free carbohydrate.     

丹皮酚及其席夫碱衍生物的抑菌性研究

以丹皮酚为先导,合成了丹皮酚缩1,3-丙二胺、丹皮酚缩2-羟基-1,3-丙二胺和丹皮酚缩糠胺3种丹皮酚席夫碱衍生物。琼脂扩散抑菌试验表明,丹皮酚及其衍生物对受试4种革兰氏阴性菌、阳性菌皆有明显的抑制作用。     

Schiff bases and their complexes: Recent progress in thermal analysis

Schiff bases are versatile compounds synthesized from the condensation of primary amino compounds with aldehydes or ketones. The high thermal of many Schiff base and their complexes were useful attributes for their application as catalysts in reactions involving at high temperatures. This thermal behavior of Schiff bases and their complexes was evaluated by TGA/DTG and DTA curves with mass losses related to dehydration and decomposition. This review summarizes the developments in the last decade for thermal analysis of Schiff bases. Therefore, synthesis of Schiff bases and their complexes are reviewed.     

Antimicrobial Polychelates: Synthesis and Characterization of Transition Metal Chelated Barbituric Acid–Formaldehyde Resin

A monomeric Schiff base was prepared by the condensation reaction of salicylaldehyde and semicarbazide, which further react with formaldehyde and barbituric acid-formed polymeric Schiff base. Its metal polychelates were then formed with Mn(II), Co(II), Ni(II), Cu(II), and Zn(II). All the synthesized compounds were characterized by elemental analysis, magnetic moment, FTIR, ¹HNMR, and electronic spectroscopies. The elemental analysis data show the formation of 1:1 [M: L] metal polychelates. Thermogravimetric analysis was carried out to find the thermal behavior of all the synthesized polymeric compounds and thermal data revealed that all the metal polychelates are more thermally stable than their parent polymeric Schiff base. All the synthesized polymeric compounds were screened for antimicrobial activity against some clinically important microorganisms, such as Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis, Staphylococcus aureus, Staphylococcus typhi, Candida albicans, Microsporum canis, and Aspergillus niger. In vitro antimicrobial activity was determined by the Agar Well Diffusion method and the result shows that all the metal polychelates exhibited better antimicrobial activity than their parent polymeric Schiff base.