在线流动注射液－液萃取系统在原子吸收光谱法中的研究及应用

本文对用于原子吸收光谱分析的在线液－液萃取流路系统进行了研究，采用了一种新型、适用、简便的相分隔器和相分离器，并用该流路系统对矿石、人发中的Ｃｕ（ＦＡＡＳ）以及矿石中痕量Ａｕ进行了测定（ＧＦＡＡＳ）。在水相和有机相的流量比为２５：１，采样频率为２０ｈ￣（－１）时，用ＦＡＡＳ法测定Ｃｕ的ＲＳＤ为１．９％（ｎ＝１０）、ＤＬ（３σ）为１．０μｇ．Ｌ￣（－１）；用ＧＦＡＡＳ法测定Ａｕ的ＲＳＤ为４．９％，ｎ＝１０、ＤＬ（３σ）为０．０８μｇ．Ｌ￣（－１）　。     

3,4-二硒方酸芳香性和气相酸性的理论研究

在ＲＨＦ／６－３１１Ｇ水平优化得到３,４－二硒方酸（３,４－二氢硒基－３－环丁烯－１,２－二酮）３ 种平面构象异构体的平衡几何构型。进一步用ＭＰ２（ｆｕｌｌ）／６－３１１Ｇ／／ＲＨＦ／／６－３１１Ｇ方法计算单点能量,发现ＺＺ型异构体是能量最低构象,且ＺＺ和ＺＥ型能量非常接近。用优化的最稳定构象ＺＺ型异构体在ＲＨＦ／６－３１１Ｇ／／ＲＨＦ／６－３１１Ｇ、ＲＨＦ／６－３１１＋ Ｇ／／ＲＨＦ／６－３１１＋ Ｇ、ＭＰ２（ｆｕｌｌ）／６－３１１＋ Ｇ／／ＲＨＦ／６－３１１＋ Ｇ 和Ｂ３ＬＹＰ／６－３１１＋ Ｇ／／Ｂ３ＬＹＰ／６－３１１＋ Ｇ水平计算其气相酸性（ΔＧ°）和同键反应芳香性稳定化能（ＨＡＳＥ）。用基团加和法（ｇｒｏｕｐ ｉｎｃｒｅｍ ｅｎｔ ａｐ－ｐｒｏａｃｈ ） 在 ＲＨＦ／６－３１１ ＋ Ｇ／／ＲＨＦ／６－３１１ ＋ Ｇ 和 Ｂ３ＬＹＰ／６－３１１ ＋ Ｇ／／Ｂ３ＬＹＰ／６－３１１＋ Ｇ水平计算其磁化率增量（Λ）。计算结果指出标题化合物的同键反应芳香性稳定化能和磁化率增量均为负值,表明它具有芳香性,实现了标题化合物芳香性的几何、能量和磁性的判定。     

3,4-二硒方酸芳香性和气相酸性的理论研究

在ＲＨＦ／６－３１１Ｇ水平优化得到３,４－二硒方酸（３,４－二氢硒基－３－环丁烯－１,２－二酮）３ 种平面构象异构体的平衡几何构型。进一步用ＭＰ２（ｆｕｌｌ）／６－３１１Ｇ／／ＲＨＦ／／６－３１１Ｇ方法计算单点能量,发现ＺＺ型异构体是能量最低构象,且ＺＺ和ＺＥ型能量非常接近。用优化的最稳定构象ＺＺ型异构体在ＲＨＦ／６－３１１Ｇ／／ＲＨＦ／６－３１１Ｇ、ＲＨＦ／６－３１１＋ Ｇ／／ＲＨＦ／６－３１１＋ Ｇ、ＭＰ２（ｆｕｌｌ）／６－３１１＋ Ｇ／／ＲＨＦ／６－３１１＋ Ｇ 和Ｂ３ＬＹＰ／６－３１１＋ Ｇ／／Ｂ３ＬＹＰ／６－３１１＋ Ｇ水平计算其气相酸性（ΔＧ°）和同键反应芳香性稳定化能（ＨＡＳＥ）。用基团加和法（ｇｒｏｕｐ ｉｎｃｒｅｍ ｅｎｔ ａｐ－ｐｒｏａｃｈ ） 在 ＲＨＦ／６－３１１ ＋ Ｇ／／ＲＨＦ／６－３１１ ＋ Ｇ 和 Ｂ３ＬＹＰ／６－３１１ ＋ Ｇ／／Ｂ３ＬＹＰ／６－３１１＋ Ｇ水平计算其磁化率增量（Λ）。计算结果指出标题化合物的同键反应芳香性稳定化能和磁化率增量均为负值,表明它具有芳香性,实现了标题化合物芳香性的几何、能量和磁性的判定。     

1,2-二硒方酸的从头计算

在ＲＨＦ／ＳＴＯ－３Ｇ和ＳＴＯ－３Ｇ＊水平上用ａｂｉｎｉｔｉｏＳＣＦ方法优化得到１，２－二硒方酸（３，４－二羟基－３－环丁烯－１，２－二硒酮）三种平面异构体的平衡几何构型，发现三种平面异构体中ＺＺ型是能量最低构象。用ａｂｉｎｉｔｉｏ数值方法在ＲＨＦ／ＳＴＯ－３Ｇ＊水平上计算了三种平面异构体的谐振动频率。     

植物草乌毒蛋白的分离及性质

介绍草乌毒蛋白提取方法。草乌根经ＰＨ７．２５ ＰＢＳ溶液（含９ｇ＝／ＬＮａＣｌ）浸提,浸提液经ＣＭ－ＳＦＦ柱和ＳｅｐｈａｃｒｙｌＳ－２００凝胶过滤柱分离,然后在高效凝胶过滤柱上制德ＡＣＯ毒蛋白,利用光电二极管列检测器的光谱性能确认色谱峰的纯度,并根据标准蛋白的相对分子质量校正曲线求得ＡＣＯ的相对分子质量,用柱后衍生荧光法测定了其氨基酸组成。     

RECl3与丝氨酸配合行为的研究

依据相平衡结果，于水中合成了ＲＥ（Ｓｅｒ）Ｃｌ３．３Ｈ２Ｏ和ＲＥ（Ｓｅｒ）２Ｃｌ３．５Ｈ２Ｏ（ＲＥ＝Ｌａ－Ｎｄ，Ｓｍ－Ｇｄ，Ｄｙ，ｙｂ，Ｙ）等２０种固态配合笺，利用化学分析，摩尔电导，ＩＲ、ＵＶ、ＦＳ、Ｘ射线衍射分析及ＴＧ－ＤＴＧ等手段对配合物进行了表征。     

纳米晶La_（1－_x）Sr_xFeO_3的合成及气敏特性的研究

用柠檬酸盐法合成出Ｌａ_（１－_ｘ）Ｓｒ_ｘＦｅＯ_３（ｘ＝０．１，０．２，０．３，０．４）原粉，再经固相反应得到纳米晶粉末，用ＴＧ、ＤＴＡ、ＸＲＤ、ＩＲ进行了表征，确证复合氧化物Ｌａ_（１－_ｘ）Ｓｒ_ｘＦｅＯ_３为钙钛矿型结构，粒径在１０～２５ｎｍ之间。实验结果表明，随着固相反应条件不同，产物粒径呈规律性变化．气敏特性研究表明，该纳米晶材料对乙醇有较高的选择性和灵敏度，其选择性顺序为Ｌａ_（０．９）Ｓｒ_（０．１）ＦｅＯ_３＞ＬａＦｅＯ_３＞ＬａＦｅＯ_３（大晶粒）。     

几个分子和负离子的QCI势能曲线

用ＱＣＩＳＤ（Ｔ）／６３１１＋Ｇ（３ｄｆ，２ｐ）（简称ＱＣＩ）计算了ＢＨ－（２Π），ＢＦ－（２Π），ＢＨ（１∑），ＢｅＨ－（１∑），ＢｅＦ－（１∑）和ＢＦ（１∑）的较完整的势能曲线，探讨了这些体系的稳定性和解离过程．同时用Ｍｏｒｓｅ函数和ＥＲ函数拟合得到势能曲线，用拟合结果计算谐性频率和非谐性频率，并与已有的实验数据（ＢＨ和ＢＦ分子）进行比较，由此考察了ＱＣＩ理论方法在远离平衡构型时的可靠性．对于因单参考态近似导致的反常势能曲线进行了ＣＡＳＳＣＦ计算．还比较了ＱＣＩ和Ｇ２理论中标准的ＭＰ２（ｆｕｌ）／６３１平衡几何构型及其对ＱＣＩ总能量的影响．     

在线流动注射液—液萃取系统在原子吸收光谱法中的研究及应用

本对用于原子吸收光谱分析的在线液－液萃取流路系统进行了研究，采用了一种新型、适用、简便的相分隔器和相分离器，并用该流路系统对矿石、人发中的Ｃｕ（ＦＡＡＳ）以及矿石中痕量Ａｕ进行了测定（ＧＦＡＡＳ）。在水相和有机相的流量比为２５：１，采样频率为２０ｈ＾－１时，用ＦＡＡＳ法测定Ｃｕ的ＲＳＤ为１．９％（ｎ＝１０）、ＤＬ（３σ）为１．０μｇ·Ｌ＾－１；用ＧＦＡＡＳ法测定Ａｕ的ＲＳＤ为４．９％，ｎ＝１０、     

A FACILE TOTAL SYNTHESIS OF (±)-SELINA-3,11-DIEN-9-OL

Ａ　ＦＡＣＩＬＥ　ＴＯＴＡＬ　ＳＹＮＴＨＥＳＩＳ　ＯＦ　（±）－ＳＥＬＩＮＡ－３，　１１－ＤＩＥＮ－９－ＯＬＡＦＡＣＩＬＥＴＯＴＡＬＳＹＮＴＨＥＳＩＳＯＦ（±）－ＳＥＬＩＮＡ－３，１１－ＤＩＥＮ－９－ＯＬＬｉＪｕｎＬＩＵ；ＺｈａｏＭｉｎｇＸＩＯＮＧ；...     

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.