吡啶羧酸类配位聚合物的研究进展

作为潜在的新型功能材料,吡啶羧酸类配位聚合物近年来得到科学家的普遍关注.本文主要对吡啶羧酸类配位聚合物在手性拆分和催化、分子磁体、非线性光学方面的研究进行了综述,列举了近年来这类配位聚合物的研究成果和开发进展,并对其发展前景作出了展望.     

苯氧羧酸类除草剂的药害与安全应用

苯氧羧酸类除草剂是一类重要除草剂 ,它在五六十年代开始投入生产应用 ,由于其价格低廉、除草速度较快、除草谱较宽、无残留等优点 ,在生产中一直发挥重要作用 ,广泛用于小麦、玉米和水稻田防除阔叶杂草。然而 ,该类除草剂对作物的安全性受环境条件、作物生育期的影响较大 ,应用不当可能会产生较重的药害 ;同时 ,该类除草剂对阔叶作物敏感、飘移和挥发性强 ,易于对周围作物阔叶发生药害。近年来 ,我们就苯氧羧酸类除草剂对作物的药害表现与安全应用方法进行了深入的研究 ,现将结果报告如下。1　苯氧羧酸类除草剂的除草原理苯氧羧酸类除草剂…     

芳氧苯氧羧酸类旋光性除草剂的研究进展

1前言当前手性农药受到人们的广泛关注,因为在消旋体的农药中,其中一半可能是没有活性的,用于农田既污染了环境又浪费了资源。西欧一些国家已经立法,对具有手性     

黄酮羧酸类化合物合成与生物活性研究进展

天然的黄酮类化合物一般不具有羧基,但在黄酮类化合物上引入羧基,便具有特殊的生理活性,这大大丰富了黄酮类化合物的家族,拓展了黄酮类化合物的应用范围及提高黄酮类化合物的生理活性。文章综述了黄酮羧酸类化合物的合成方法及其生理活性进展。     

苯氧羧酸类化合物合成反应机理与影响因素分析

从苯氧羧酸类化合物合成反应机理出发,总结并深入分析了温度、时间、体系pH值、N2保护、催化剂、水用量、原料配比及加料方式等因素对苯氧羧酸类化合物合成反应的影响。     

咪唑羧酸类配合物的研究

简要介绍了当前咪唑羧酸类配合物的研究进展,从配体的特点、配合物的制备、以及应用方面进行了概述。     

配位聚合物的研究进展

综述了近年来比较热门的研究领域——配位聚合物,它是由过渡金属和有机配体自组装而形成的,具有独特的空间几何构型,在非线性光学材料、磁性材料、超导材料,微孔材料及非对称催化等诸多方面都有广阔的应用前景。本文就不同配体的配位聚合物进行了分类研究。     

苯氧羧酸类除草剂的手性毛细管电泳

以7-CD为毛细管电泳手性选择剂,对苯氧羧酸类除草剂对映体的分离进行了研究。考察了手性选择剂的种类、7-CD浓度、SDS浓度、背景电解质浓度、pH值等对分离的影响。结果发现,选择30mmol·L11rCD＋100mmol·L11SDS＋75mmol·L-1H3P04作为电泳缓冲体系（pH值2．O）,2,4-滴丙酸、2,4,5-滴丙酸、2-（3-氯苯氧基）丙酸对映体完全分离,2-（4-氯苯氧基）丙酸、2-苯氧基丙酸对映体部分分离,分离度分别为3．42、8．27、2．83、0．89、0．50。     

水样中苯氧羧酸类除草剂固相萃取检测

目的利用计算机分子模拟技术选择合适的功能单体以制备固相萃取柱,用来检测池塘水样中苯氧羧酸泪除草剂。方法利用计算化学方法筛选出最优的功能单体,并用其制柱,并对池塘中水样进行检测。结果顺利制成萃取率较高的萃取柱,测得回收率达到83.9%。结论计算机模拟能够在法庭科学方面成功代替部分常规实验,大大节约了人力物力。     

纳米多孔配位聚合物的研究进展

纳米多孔材料可用作催化剂、气体储存材料和光电子器件,是目前新型多孔材料的研究热点之一.借助自组装技术,选择羧酸类、联吡啶类和吡啶羧酸类化合物作为桥联配体,可获得一维、二维和三维的多孔配位聚合物.简要综述了该类纳米多孔配位聚合物的设计原理、合成路线和应用前景,评价了其合成方法的优缺点.由于其特殊的结构和性质,纳米多孔配位聚合物将发展成为具有光、电、磁等性质的多功能材料.     

金属配合物抗癌活性的研究进展

介绍了铂配合物、Schiff碱金属配合物及稀土金属配合物的抗癌活性研究现状。     

Fingerprinting and characterization of carboxylic acids in in-situ oil shale retort and process waters by capillary column gas chromatography-mass spectrometry

Six important in-situ oil shale retort and process waters have been analysed for carboxylic acids by capillary column gas chromatography-mass spectrometry. A fingerprint or profile was obtained for Occidental boiler blowdown process water, retort water and heater-treater process water; Geokinetics retort water, and Laramie Energy Technology Center Omega-9 and 150 Ton retort waters. The results clearly show significant differences in that each retort or process water contains various mono-, di-, branched, keto-aliphatic and aromatic carboxylic acids. The Occidental retort and process waters contained straight-chain monocarboxylic acids from C₂–C₁₃ and C₂–C₁₄, whereas the Geokinetics retort water contained C₂–C₁₀, the 150 Ton retort water C₂–C₁₀, and Omega-9 retort water C₂–C₁₄ acids. Variations among the retort waters and process waters were more important for the normal dicarboxylic acids. The Occidental retort and process water contained no C₂–C₇ straight-chain dicarboxylic acids, but those from C₈–C₁₂ were present. The Omega-9 retort water contained all the straight-chain dicarboxylic acids, C₂–C₁₂, that were identified, whereas the 150 Ton sample contained only C₂ and C₄ dicarboxylic acids, and the Geokinetics sample C₂–C₄ and C₈–C₁₂ acids. The implications of the results in pyrolysis of oil shale kerogen are discussed.     

Chemoenzymatic synthesis of chiral carboxylic acids via nitriles

BACKGROUND: Enantiomerically pure 1,4‐benzodioxane‐2‐carboxylic acid derivatives are useful building blocks for the synthesis of pharmaceuticals and biologically active compounds whose interaction with their biological target (enzyme, receptor) depends very much on the absolute configuration of the chiral carbon at the 2‐position. The aim of the present work is to investigate the route to racemic nitriles and the subsequent selective enzymatic hydrolysis by nitrilase to optically active 1,4‐benzodioxane‐2‐carboxylic acid and 6‐formyl‐1,4‐benzodioxane‐2‐carboxylic acid. RESULTS: A range of microbial nitrilases from Rhodococcus, Alcaligenes and Pseudomonas strains have been prepared and screened for the desired biotransformations using a chiral high performance liquid chromatography (HPLC) analytical method. The nitrilase from Alcaligenes faecalis ATCC 8750 showed the highest and the nitrilase from Rhodococcus rhodochrous NCIMB 11216 the lowest activity towards 2‐cyano‐6‐formyl‐1,4‐benzodioxane. Lyophilised cells of Rhodococcus R 312 gave the (R)‐1,4‐benzodioxane‐2‐carboxylic acid with high enantioselectivity after 25% conversion. Excellent enantioselectivities for the hydrolysis of both 2‐cyano‐1,4‐benzodioxane as well as 2‐cyano‐6‐formyl‐1,4‐benzodioxane have been achieved and the absolute configuration of 1,4‐benzodioxane‐2‐carboxylic acid was determined to be R by comparison with the specific rotation of commercially available (R)‐1,4‐benzodioxane‐2‐carboxylic acid. CONCLUSIONS: This new nitrilase‐catalysed kinetic resolution of 2‐cyano‐ and 2‐cyano‐6‐formyl‐1,4‐benzodioxane opens a mild route to optically active 1,4‐benzodioxane‐2‐carboxylic acids. As the formyl functional group would be damaged in chemical nitrile hydrolysis, nitrilase‐catalysed hydrolysis solves this synthetic bottleneck and advances nitrilase biocatalytic tools for the preparation of more complex 1,4‐benzodioxane‐2‐carboxylic acids. Copyright © 2007 Society of Chemical Industry     

Dehydration of carboxylic acids on the MgO(100) surface

The interaction of formic and acetic acids with the MgO(100) surface has been studied under UHV conditions using XPS and TPD. Both acids dissociated heterolytically on the MgO surface, forming surface formate and acetate species respectively. The carboxylates decomposed at 520 K into dehydration products H₂O + CO from HCOO, and H₂O+CH₂CO from CH₃COOH.     

Extractable metal salts of carboxylic acids in Green River oil shale

A study of solvent-extractable metal salts of carboxylic acids from Colorado Green River oil shale is presented. Sodium was found to be the most abundant cation present in these acid metal salts. Identification of individual components is based on combined gas Chromatographic and mass spectrometric results obtained for their respective volatile methyl esters. Normal acid salts (C₁₁ to C₃₄), isoprenoid acid salts (C₁₅ to C₁₇, C₁₉ to C₂₂), nonisoprenoid branched acid salts (C₁₄ to C₁₉), terpenoid acid salts (C₃₀ to C₃₂), and α,ω-dicarboxylic acid salts (C₁₁ to C₂₉) were identified. Small concentrations of cyclohexyl acid salts and aromatic acid salts were also found. The high even-odd predominance for the distribution of normal acid salts indicates a mild thermal history for Green River oil shale. Some acid salts (45.6 wt%) were not identified because of nonvolatility of their methyl esters.     

膦酰基羧酸共聚物阻垢分散剂的研究进展

介绍了近20年来膦酰基羧酸共聚物阻垢分散剂——大分子有机磷酸的研究现状和进展情况。重点罗列了以不饱和有机磷酸单体为原料制备膦酰基羧酸共聚物阻垢分散剂，在合成工艺和阻垢、分散及缓蚀性能评价等方面所取得的研究成果，并提出了膦酰基羧酸共聚物阻垢分散剂今后的主攻方向和发展趋势。     

吡啶类配合物的研究热点

吡啶类配位聚合物是一种新型功能性分子材料,近年来得到科学家的普遍关注。作者主要对吡啶类配位聚合物在金属一氧簇化合物、缠结网络、功能特性的研究热点进行了综述,综述了吡啶类配位聚合物研究的重要性和国内外吡啶类配位聚合物的研究工作,并对其发展前景作出了展望。     

Flame‐retardant finishing of cotton fabrics using polyamino carboxylic acids and sodium hypophosphite

The purpose of this research was to use polyamino carboxylic acids (PACAs) and their combination with sodium hypophosphite (NaH₂PO₂) as a flame‐retardant finishing system for cotton fabrics. Flammability of cotton fabric was evaluated by 45° flammability test, differential scanning calorimetry and measuring the char yield. The combination of polyamino carboxylic acids and sodium hypophosphite as a phosphorus‐containing catalyst reduces the flammability of cotton. The pyrolysis properties and the results of char yield of the finished cotton show that with increasing amount of catalyst, the flame retardancy increases. Fastness against multiple laundering, whiteness and tensile strength of the cotton finished with PACAs/NaH₂PO₂ to multiple standard laundering have been studied, too. The flame retardancy effect has an acceptable washing fastness. Whiteness and tensile strength of the finished cotton do not change significantly. Copyright © 2012 John Wiley & Sons, Ltd.     

Membrane transport of organics. III. Permeation of some carboxylic acids through bipolar polymer membrane

The permeation of acetic (AA), propionic (PA), lactic (LA), oxalic (OA), citric (CA), and tartaric (TA) acids through the bipolar ion‐exchange membrane Neosepta BP‐1 (Tokuyama Corp.) was studied. It was found that the fluxes (J, mol cm^?2 s^?1) and mass‐transfer coefficients (k, cm s^?1) increase in the following order: CA < OA < LA < TA < PA ≤ AA. The transport processes in the Neosepta BP‐1 membrane are concentration‐dependent and can be described phenomenologically using I‐Fick's law for diffusion. The permeation phenomena correspond to the solution–diffusion model similarly as to the permeation of carboxylic acids through strongly acidic cation‐exchange membranes. However, in competitive AA–PA transport experiments, typically for strongly basic membranes, the separation ability of the BP‐1 membrane with a preference toward AA was observed. The selectivity coefficients α calculated as the ratio of the respective mass‐transfer coefficients vary in the range from 1.31 ± 0.2 to 2.1 ± 0.6. These values depend on the feed composition and the system arrangement, which means that α is always higher for the system with the anion‐exchange layer is in contact with a feed solution. Rather low fluxes of PA, AA, and other acids, as compared to some monopolar membranes (Neosepta AFN‐7, Nafion‐120, Flemion), are promising for the application of the bipolar membrane in an electrodialytic separation of carboxylic acids from their aqueous solutions or mixtures. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2705–2717, 2001