氯化亚铜中亚铜及高价铜盐含量的示波滴定

１引言氯化亚铜含量的测定在国家标准分析方法中是根据亚铜离子能使Ｆｅ３＋还原为Ｆｅ２＋，然后以邻菲啉－硫酸亚铁络合物作指示剂用高铈盐进行滴定。氯化亚铜中高价铜盐测定则利用高价铜盐能溶于５ｍｏｌ／Ｌ乙酸．而亚铜盐不能溶解进行分离，然后再用碘量法进行测定，手续十分麻烦。本文根据ＣＵ（Ⅰ）与四苯硼钠定量生成沉淀，用示波滴定法中的四苯硼钠法进行氯化亚铜含量的测定，高价铜盐被抗坏血酸还原，再用四苯硼钠法进行滴定，差量法计算出高价铜盐含量，操作简便，终点直观，测定结果准确。２实验部分２．１主要仪器与试剂ＬＳ－…     

尿素中氮含量的示波滴定新方法

研究了尿素中氮含量的示波滴定新方法，样品用硫酸消化法分解，分子中的氮转化为铵，用四苯硼钠（Ｎａ－ＴＰＢ）沉淀铵，过量的四苯硼钠用氯化四乙基铵标准溶液返滴定，以四苯硼钠示波图切口消失为终点，再计算出氮含量。本法不需要蒸馏吸收，选用无毒的滴定剂，不用外加指示剂，与通用的产品标准分析方法相比较，操作简便、快速，测定结果准确、可靠。     

磺胺嘧啶银含量的示波滴定

报道了用示踪滴定法测定磺胺嘧啶银的新方法，新品用硝酸溶解后加入四苯硼钠（Na-TPB)沉淀银，过量的TPB在PH≥12的NaOH-NaAc介质中，用四乙基氯化铵标准溶液返滴定，以示波滴定荧光屏上Na-TPB的示波图切口突然消失指示滴定终点。方法快速简便，标准加入回收率在99．5％－100．5％，RSD＜0．2％。     

交流示波极谱滴定法测定氧氟沙星的研究

报道了用交流示波极谱滴定法测定氧氟沙星（ＯＦＸ）含量。用ｐＨ４．０的ＨＡｃ－ＮａＡｃ缓冲溶液溶解样品，加入过量的四苯硼钠（Ｎａ－ＴＰＢ）使药样沉淀完全１，过滤后滤液用硫酸亚铊标准溶液进行返滴定，由示波极谱图［ｄＥ／ｄｔ＝ｆ（Ｅ）］上ＴＰＢ切口的消失指示滴定终点。应用于片剂和注射剂测定，平均加标回收率为１００．０２％，相对标准偏差≤０．１７％。     

银合金中银、铜含量的示波滴定

报道了用示波滴定银合金中银、铜的含量。试样酸溶后,取部分试液,在pＨ５～６的ＨＡc－ＮaＡc缓冲介质中用四苯硼钠（Ｎa－ＴＰＢ）法示波滴定银。另取部分试液,加Ｖe使Ｃu＾２＋还原为Ｃu＾＋,用Ｎa－ＴＰＢ法示波滴定铜,而Ａg＋被还原为Ａa,避免了测定铜的干扰。该方法标准加入回收率为９９．８％～１００．２％,ＲＳＤ〈０．２％。     

金属配合物高效液相色谱法测定人发和血清中锌,钴,铜的含量

选用8-羟基喹啉为配合剂，经柱前衍生后高效波相色谱法分离测定，建立了人发和血清中微量元素锌、钴、铜的含量测定方法，该法配合产物稳定性好，标准曲线的线性范围锌、铜均为0．8～4．0mg／L，钴为0．1～2．0mg／L，相关系数均0．999以上，批内、批间相对标准偏差均小于5％，加样回收率锌为（100．3±0.47）％，钴为（98．9±2．07）％，铜为（100.9±0．65）％。     

烃铵盐用于示波极谱滴定法测定诺氟沙星

本文报道了以烃铵盐为滴定剂，用交流示波极谱四苯硼钠（Ｎａ－ＴＰＢ）滴定法测定诺氟沙星（ＮＦＸ）的含量。应用于胶囊样品的测定，与药典法测得结果基本一致，最大相对误差≤０．５６％，最大ＲＳＤ为０．２９％，平均回收率为１００．６％。     

配位滴定法连续测定铜和锌的新指示剂

对2-（3，5-二氨-2-吡啶偶氮）-5-二甲基苯胺（3，5-diCl-PADMAB）作指示剂络合滴定铜和锌进行了研究。在pH5．0的乙酸-乙酸钠介质中，以3，5-diCl-PADAMAB作指示剂，EDTA为滴定剂连续测定铜和锌，滴定终点颜色变化敏锐，准确度高，铜和锌量各在0～20mg范围内与EDTA量成正比。方法用于合金中铜和锌的测定，分析结果的相对标准偏差为〈0．1％和〈0．4％。     

用N2O-C2H2原子吸收光谱法测定铜银合金中铁

提出用N2O-C2H2火焰原子吸收光谱法测试镉镍电池材料铜银合金中铁含量．方法具有良好的灵敏度,干扰少,重现性好．铁含量在0．1～30．0mg／L范围内与吸收值呈良好的线性关系．在测试铁含量为6．26mg／L（测定次数n=10）时,其相对标准偏差小于1．0％．标准回收率在97．0%-99．0％（n=6）范围内,适用于镉镍电池材料铜银合金中铁含量的质量控制分析和样品系统分析,结果令人满意．     

间接原子发射光谱法测定氢溴酸山莨菪碱

研究了电感耦合等离子体-原子发射光谱法间接测定氢溴酸山莨菪碱。在pH5．0溶液中过量四苯硼钠可使氢溴酸山莨菪碱沉淀完全，加入氯化钾沉淀滤液中剩余的四苯硼钠，测定滤液中过量的钾，可以计算得到氢溴酸山莨菪碱的含量。方法简单快速，回收率在97％～102％之间，相对标准偏差为1．3％。     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.     

Sulfur-directed metal-free and regiospecific methyl C(sp3)–H imidation of thioanisoles

Regiospecific and direct imidation of the methyl C(sp³)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products.     

Selective syntheses of 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones via temperature-dependent Rh(II)-carbenoid-mediated 2H-azirine-ring expansion

The Rh(II)-catalyzed reaction of 2-carbonyl-substituted 2H-azirines with ethyl 2-cyano-2-diazoacetate or 2-diazo-3,3,3-trifluoropropionate provides an easy access to 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones. These compounds can be selectively prepared from the same starting material using temperature as the only varied parameter. The 2-azabuta-1,3-diene intermediate, a common precursor for both heterocyclic products, isomerizes into 2H-1,3-oxazine under kinetic control, while 1H-pyrrol-3(2H)-one is the sole product of the reaction at elevated temperatures. According to DFT-calculations a one-atom oxazine ring contraction involving ring-opening to a 2-azabuta-1,3-diene intermediate, followed by a 1,5- and 1,2-prototropic shift leads to the consecutive formation of imidoylketene and azomethine ylide, which then further undergo cyclization to the pyrrole derivative.     

Copper catalyzed/mediated synthetic methodology for ebselen and related isoselenazolones

Scope of the copper catalyzed/mediated selenium-nitrogen coupling reaction has been studied for the synthesis of isoselenazolones. It is noticed that the 2-chloro, 2-bromo-, and 2-iodo-aryl amides substrates can be exploited in the selenium-nitrogen coupling reaction by employing 25-100 mol % of CuI/1,10-phenanthroline (L) and potassium carbonate as a base in DMF. Furthermore, electron rich 2-chloro-arylamides also underwent selenium-nitrogen coupling reaction to give biologically important selenium-nitrogen heterocycles. Also, copper-catalyzed selenium-nitrogen coupling reaction has been meticulously applied for the synthesis of diaryl diselenides having methoxy, amine, and amide functionality from respective aryl iodides in the presence of stoichiometric amount of succinimide as an external Se-N coupling partner.     

Knoevenagel condensation catalyzed by novel Nmm-based ionic liquids in water

A series of novel N-methyl morpholine (Nmm) based ionic liquids with 1,2-propanediol group were synthesized and used as catalysts for Knoevenagel condensation at room temperature in water. Under the effect of the catalyst, various aldehydes or aliphatic ketones could react with a wide range of activated methylene compounds well, including malononitrile, alkyl cyanoacetate, cyanoacetamide, β-diketone, barbituric acid, 2-arylacetonitrile and thiazolidinedione. Furthermore, most of the products could be separated just by filtrating and washing with water. Additionally, the catalyst is recyclable and applicable for the large-scale synthesis.     

Construction of polyheterocyclic spirotetrahydrothiophene derivatives via sulfa-Michael/aldol cascade reaction

A series of polyheterocyclic spirotetrahydrothiophene derivatives were obtained in moderate to excellent yields via a catalyst-free sulfa-Michael/aldol cascade reaction of chalcones 1 and commercially available 1,4-dithiane-2,5-diol 2 under mild conditions. We also present the first asymmetric sulfa-Michael/aldol cascade reaction of chalcones 1 and commercially available 1,4-dithiane-2,5-diol 2 with moderate to good enantioselectivities catalyzed by readily available chiral phase-transfer catalysts (PTCs).     

Suzuki-Miyaura reactions of the soluble guanylate cyclase inhibitor NS2028: a non-product specific route to C-8 substituted analogues

Both soluble guanylate cyclase (sGC) inhibitors ODQ 1 and NS2028 2 are synthesized via improved protocols. In the former case treating 3,4-dihydroquinoxalin-2(1H)-one oxime 8, which can be prepared in two steps from 1,2-benzenediamine, with 1,1′-carbonyldiimidazole (CDI) gives the dihydro-ODQ 10 that in the presence of KMnO₄ oxidises to give ODQ 1 in an overall yield of 46% starting from 1,2-benzenediamine. In the latter case, the synthesis affords NS2028 2 from 2-amino-4-bromophenol 3 in three steps with an overall yield of 85% and avoids the need for chromatography. Furthermore, Suzuki-Miyaura reaction conditions are described that enable the preparation of 8-aryl and 8-heteroaryl derivatives of NS2028 directly from NS2028 2. Finally, demethylation of the 8-(methoxyphenyl) substituted analogues afforded the 8-(hydroxyphenyl) derivatives 40-42. All new products are fully characterised.