对叔丁基杯[4]芳烃乙酸萃取Cr~(3+)的反应研究

报道了以对叔丁基杯[4]芳烃乙酸(简称杯[4]水解)为萃取剂,从硝酸体系中萃取Cr3+的反应机理及反应热力学性质。通过考察溶液pH值对萃取分配比的影响,确认杯[4]水解萃取Cr3+的机理,并得到了萃取反应的表观平衡常数K=1.815×103;通过考察反应温度对分配比的影响,求得萃取热焓ΔH=69.89 kJ/mol;由ΔH和表观平衡常数K计算了自由能ΔG=-18.601 kJ/mol和熵变ΔS=294.97 J/(mol-1.K-1)。杯[4]水解萃取Cr3+的反应是一个吸热反应。     

氨基苯甲酸酯杯[4]芳烃衍生物的合成及性能研究

以对叔丁基杯[4]芳烃为原料,与1,2-二溴乙烷反应得到25,27-二(2-溴乙氧基)-26,28-二羟基-5,11,17,23-四叔丁基杯[4]芳烃,分别与苯佐卡因、三卡因、盐酸普鲁卡因在K2CO3、Na I/DMF体系中反应,以48%~63%的产率合成了3种新型含氨基苯甲酸酯结构的杯[4]芳烃衍生物——25,27-二(2-(对乙氧羰基苯基)氨基)乙氧基-26,28-二羟基-5,11,17,23-四叔丁基杯[4]芳烃、25,27-二(2-(3-乙氧羰基苯基)氨基)乙氧基-26,28-二羟基-5,11,17,23-四叔丁基杯[4]芳烃和25,27-二(2-(4-(2-(二乙基氨基))乙氧羰基苯基)氨基)乙氧基-26,28-二羟基-5,11,17,23-四叔丁基杯[4]芳烃。新化合物的结构与构象经元素分析、IR、1HNMR表征证实。研究它们对K+、Pb2+等9种金属离子的萃取性能以及对氨基酸的分子识别作用。结果表明,新型杯[4]芳烃衍生物对过渡金属离子具有良好的萃取效果,对Fe2+、Cu2+、Pb2+、Zn2+、Ag+的萃取率高达90%以上;同时与氨基酸也能发生很好的配合作用,能有效地识别氨基酸,对带芳环的氨基酸比脂肪氨基酸的识别效果更好。     

对叔丁基杯[4]及杯[6]芳烃的合成及其对铜离子的萃取研究

以对叔丁基苯酚和甲醛为原料,分别对对叔丁基杯[4]及杯[6]芳烃的合成和萃取性质进行了研究．结果表明,在本研究范围内,以KOH为催化剂,对叔丁基杯[6]芳烃的最高产率为77．8％;以NaOH为催化剂,对叔丁基杯[4]芳烃的最高产率为47．3％。对于对叔丁基杯[4]和杯[6]芳烃,最佳的反应回流温度都为140℃。对叔丁基杯[6]芳烃对模拟废水中的铜离子具有一定的萃取效果,最高萃取率为70．3％。     

杯[4]芳烃偶氮衍生物的合成及其金属离子萃取性能

杯芳烃作为超分子化学的重要组成部分,近年来得到了快速发展并成为化学家的研究热点。以脱叔丁基-杯[4]芳烃为原料合成了杯[4]芳烃偶氮衍生物,其结构经IR和1H NMR所表征。研究了该主体分子对金属离子的萃取性能,实验结果表明,该主体分子对Mg2＋具有较高的萃取作用。讨论了主客体间配位作用的机制。     

乳化萃取法脱除Mg2+制备工业级磷酸二氢钠的研究

本文以高效的二(2-乙基己基磷酸)(D2EHPA)为萃取剂,采用乳化萃取技术来提取NaH2PO4溶液中的Mg2+杂质,通过考察萃取剂浓度,水相溶液pH值,相比(水相:有机相),乳化速度等对萃取Mg2+萃取率的影响,求得适宜工艺条件:D2EHPA体积分数:75%,相比(A/O):2∶1,起始NaH2PO4溶液pH值为4,搅拌速度:3000r.min-1;实验结果表明,在适宜工艺条件下,经过三级萃取,可制取工业级NaH2PO4。     

对叔丁基杯[6]芳烃与黑索金的配合研究

对叔丁基苯酚和甲醛在KOH催化下制备对叔丁基杯[6]芳烃。用荧光光谱法研究了对叔丁基杯[6]芳烃与黑索金(RDX)在溶液中的相互作用,结果表明对叔丁基杯[6]芳烃与RDX在溶液中存在较强的配合作用,RDX的激发峰发生明显红移,荧光强度增强,主客体间发生了包合作用。通过对叔丁基杯[6]芳烃-RDX配合物的发射光谱与紫外光谱分析,确定了在DMF溶液中对叔丁基杯[6]-RDX配合物的化学计量比为1∶1,稳定常数为325.70。     

杯[4]芳烃咪唑盐的微波合成及在氟化反应中的应用

以杯[4]芳烃为起始原料,首先制得中间体杯[4]芳烃双溴代烷基衍生物,然后经微波辐射和阴离子交换,共得9种杯[4]芳烃咪唑盐衍生物,化合物的结构与构象经元素分析、IR、1HNMR、19FNMR、31PNMR表征.研究了它们在对氯硝基苯氟化反应中的催化性能以及对K+的萃取性能.结果表明,这9种化合物在氟化反应中的催化效果良好,对氟硝基苯的收率为80.89％～92.67％;同时化合物对K+具有较好的萃取效果,其中以化合物25,27-二[4-(3-甲基咪唑)乙氧基]-26,28-二羟基-5,11,17,23-四叔丁基杯[4]芳烃六氟磷酸盐的萃取效果最好,萃取率可达75.45％.     

新型杯[4]芳烃衍生物对Pb~(2+),Cd~(2+)的萃取性质

研究了新型杯[4]芳烃D对Pb2+,Cd2+离子的液-液萃取性质,并将其与自制的杯[4]芳烃A及其衍生物B、C对Pb2+,Cd2+离子的液-液萃取性质进行了比较。结果表明,与化合物A~C相比,D对Pb2+萃取率最高,在实验条件下,可达到42.8%;测试的四种化合物对Cd2+离子的萃取效率均不佳,未经任何修饰的杯[4]芳烃A的萃取效率最高,仅8.5%。推测对Cd2+的萃取为阳离子交换机理。     

新型杯[4]芳烃衍生物对Pb2+,Cd2+的萃取性质

研究了新型杯[4]芳烃D对Pb2+,Cd2+离子的液-液萃取性质,并将其与自制的杯[4]芳烃A及其衍生物B、C对Pb2+,Cd2+离子的液-液萃取性质进行了比较.结果表明,与化合物A～C相比,D对Pb2+萃取率最高,在本实验条件下,可达到42.8%;测试的四种化合物对Cd2+离子的萃取效率均不佳,未经任何修饰的杯[4]芳烃A的萃取效率最高,仅8.5%.推测对Cd2+的萃取为阳离子交换机理.     

杯芳烃／聚丙烯共混体系耐热氧性能的研究

合成了对叔丁基杯[4]、杯[6]、杯[8]芳烃,并用热重法和烘箱老化评价了共混体系的耐热氧性能。结果表明,杯芳烃能明显提高聚丙烯的耐热氧性能,其耐热氧能力为：对叔丁基杯[6]芳烃＞对叔丁基杯[4]＜2,6－二叔丁基－4－甲基苯酚。     

Study on Mg<Superscript>2+</Superscript> removal from ammonium dihydrogen phosphate solution by solvent extraction with di-2-ethylhexyl phosphoric acid

The extraction of Mg²⁺ from ammonium dihydrogen phosphate (MAP) solution by extractant (D2EHPA) and its mixture, including acidic extractant (HEHPEHE), alkaline extractant (TOA) and neutral extractant (TBP) respectively, is investigated. The good extraction selectivity of Mg²⁺ with D2EHPA from ammonium dihydrogen phosphate solution is verified, which is found to be associated with the cation exchange and chelation capability of D2EHPA on the basis of its molecular structure. The related thermodynamic data are also obtained in terms of experimental results as follows: the extraction enthalpy is 2.659×10⁻² (J·mol⁻¹·K⁻¹), the free energy is 1.501×10³ (J·mol⁻¹) and the entropy is 4.441 (J·mol⁻¹). Meanwhile, the major influencing factors, such as the initial pH, the initial concentration of extractant, phase ratio and the extraction temperature on the extraction ratios of Mg²⁺, are studied, and the optimal process conditions are obtained. As shown in the extraction experiments for practical MAP solution, superior grade MAP can be obtained by three levels of extraction under optimal condition.     

Extraction of Pb2+ with p-tert-butylcalix [4]-, [5]-, [6]Arene Carboxylic Acid Ligands and their Monomeric Counterpart: A Thermodynamic Approach

Studies on extraction equilibrium constants at different temperatures and thermodynamic parameters of solvent extraction of Pb²⁺ ion with carboxylic acid derivatives of different ring size calixarenes and structure related monomeric compound have been carried out. The extraction equilibrium constants corresponding to calix[n]arene (n?=?4, 5, 6) derivatives decrease in the order [5]arene > [6]arene > [4]arene. In all cases, the complexation process is primarily enthalpy driven. The favorable enthalpic contribution for extraction of Pb²⁺ is in the order hexamer ≈ monomer > tetramer > pentamer. However, the unfavorable entropic loss follows the order: monomer > hexamer > tetramer > pentamer. Overall stability of the host-guest complex is the function of entropy-enthalpy compensation and the free energy of complexation is minimum for the pentamer, followed by tetramer ≈ hexamer and monomer. Although the carboxylic acid derivative of calix[4]arene is more preorganized than the calix[5]arene derivative, extraction of Pb²⁺ ion with the tetramer passes through greater entropic loss than that with the pentamer and the degree of preorganization of calix[4]arene derivative is far from perfect for the complexation and extraction of Pb²⁺ ion. As compared to tetrameric and hexameric counterparts, the structural features of the carboxylic acid derivative of calix[5]arene prior to complexation contribute much to interact with the Pb²⁺ ion and form a thermodynamically stable complex. Supplementary materials are available for this article. Go to the publisher's online edition of Solvent Extraction and Ion Exchange to view the supplemental file.     

以光卤石、纯化磷酸为原料制取磷酸二氢钾

介绍了以高氯酸铵(NH_4ClO_4)沉淀高氯酸钾(KClO_4)以回收光卤石中的钾,所得的KClO_4以一定摩尔比加到磷酸水溶液中,并以叔胺类(N_(235))萃取剂用萃取的方法去除高氯酸(HClO_4)后制得磷酸二氢钾,被萃取的HClO_4经用氢氧化铵(NH_4OH)水溶液反萃后(得到 NH_4ClO_4)可循环使用。通过实验确定了最佳工艺条件。     

Study of electrochemical phosphate sensing systems: Spectrometric, potentiometric and voltammetric evaluation

Characterization of the interaction of a urea-functionalized calix[4]arene ionophore and phosphate was undertaken by combination of nuclear magnetic resonance (NMR) spectrometry, potentiometric selectivity coefficient evaluation and voltammetric ion transfer at the interface between two immiscible electrolyte solutions (ITIES). NMR revealed that the urea protons were involved in complexation with the target anion and potentiometric separate solution selectivity data indicated selectivity for phosphate over chloride and sulphate. Voltammetry at the ITIES confirmed that the ionophore-facilitated transfer of monohydrogen phosphate occurred in preference to dihydrogen phosphate transfer. The results correlate with previously reported data on the potentiometric evaluation of this calixarene as an anionophore in PVC-membrane electrodes. The data provide the basis for development of amperometric monohydrogen phosphate sensors based on the ion-transfer principle.     

磷酸二氢钾生产装置氯化铵结晶体系稳定运行优化技术

云南云天化红磷化工有限公司3万t/a磷酸二氢钾生产装置系采用有机溶剂萃取法生产磷酸二氢钾, 氯化铵是生产磷酸二氢钾的副产物,主要用于肥料及添加剂。从氯化铵结晶装置的运行情况来看,氯化铵结晶系统每运行10 d左右,就得停车对系统内的母液进行油水分离、升温溶解、过滤处理,每次处理时间需要4~6 d,致使装置开车率低,成为磷酸二氢钾装置长周期稳定运行的制约因素。为延长氯化铵结晶体系稳定运行周期,从氯化铵原液的品质、离心机滤网与推料面的间隙、离心机滤网规格、氯化铵结晶器高位溢流管、氯化铵母液的细晶消除等方面提出了优化及改进措施。通过改进,氯化铵结晶体系得以稳定运行,磷酸二氢钾生产装置月开车率由40%~50%上升至75%以上。     

Synthesis of novel silica gel immobilized‐calix[4]arene amide ionophores and their anion binding abilities toward phosphate and chromate anions

This article describes the synthesis and characterization of four new calix[4]arene ionophores 5–7 and 9 and corresponding two new silica gel‐immobilized calix[4]arene ionophores containing pyridine 10 and 11 via modification of calix[4]arene monoamide derivatives 5 and 6 with aminopropyl silica gel, respectively. The extraction studies have been performed using liquid–liquid extraction for receptors 5–7 and 9 and solid–liquid batchwise sorption procedures for receptors 10 and 11 . Obtained extraction results showed that the immobilized‐calix[4] arene ionophores 10 and 11 have high extraction ability toward chromate and phosphate anions as compared to their corresponding monomeric precursors 5 and 6 . © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012