铁氰化钾-Fe(Ⅲ)体系测定盐酸异丙肾上腺素

本文建立了以铁氰化钾-Fe(Ⅲ)体系测定盐酸异丙肾上腺素的方法。研究表明,在pH 3.0,盐酸异丙肾上腺素可使Fe(Ⅲ)还原为Fe(Ⅱ),生成的Fe(Ⅱ)可以与K_3[Fe(CN)_6]反应生成可溶性普鲁士蓝(KFe~(Ⅲ)[Fe~(Ⅱ)(CN)_6)。盐酸异丙肾上腺素的浓度在0.03~5.00μg·m L~(-1)范围内与吸光度呈现良好线性关系,线性回归方程A=0.017+0.57779C(μg·m L~(-1)),相关系数R=0.9997,检出限为0.025μg·m L~(-1),相对标准偏差R.S.D.=1.05%(n=11),间接测定盐酸异丙肾上腺素的摩尔吸光系数ε=1.4×105L·mol~(-1)·cm~(-1)。本方法成功用于药物制剂和生物样品中盐酸异丙肾上腺素含量的测定,结果满意。     

A Study on Thermal Decomposition of K_3[Fe(CN)_6] and KFe[Fe(CN)_6] in Helium

K3 [Fe(CN)6] and KFe[Fe(CN)6] are classical coordination compounds. However, the mechanism of decomposition reactions has not been well expounded. The gas products of thermal decomposition were examined by gas chroma tography (GC) , and the structure of the solid products by Mossbauer spectroscopy(MS) and X-ray diffraction(XRD). The findings are explained in terms of the theory of coordination chemistry and a decomposition mechanism is proposed in this study. On the basis of various experimental results, the first stage of the decomposition of K3[Fe(CN)6] in He was found to be the evolution of(CN)2 resulting in the reduction of Fe(Ⅲ)12K3 [Fe(CN)6]→9K4[Fe(CN)6] + Fe2 [Fe(CN)6] + 6 ( CN )For KFe [Fe(CN) 6 ], the first stage of decomposition man be represented as6KFe[Fe(CN)6]→3K2Fe[Fe(CN)6] + 2Fe2[Fe(CN)6 + 3(CN)2At higher temperatures, the decomposition of both K3[Fe(CN)6) andKFe[Fe(CN)6] to form KCN and Fe2C was accomplished by the release of(CN)2 and N2.     

铁氰根桥联的一维链状大环配位聚合物的合成及结构

配位聚合物的合成、结构和性质研究近年来引起了人们极大的兴趣 ,已成为配位化学最活跃的研究领域之一 .由于 [Fe( CN) 6 ]3- 和 [Fe( CN) 6 ]4- 离子本身具有丰富的配位特性 ,可与金属离子及其配合物形成一维链状、二维网状和三维立体结构的配位聚合物 [1～ 5] ,铁氰根和亚铁氰根桥联的配位聚合物的研究成为其中的研究热点之一 .此外 ,铁氰根和亚铁氰根桥联的配位聚合物具有较高的铁磁相变温度[6～ 8] ,是一类具有较好应用前景的分子磁体 .但是 ,以金属大环配合物作为结构单元与 [Fe( CN) 6 ]3-和 [Fe( CN) 6 ]4-离子形成的配位聚合物…     

Cyanide-bridged complexes based on dinuclear Cu(II)-M(II) [M = Pb and Cu] building blocks: Synthesis, crystal structures and magnetic properties

Four cyanide-bridged heterometallic complexes {[CuPb(L 1 )][Fe III (bpb)(CN) 2 ]} 2 ·(ClO 4 ) 2 ·2H 2 O·2CH 3 CN (1), {[CuPb(L 1 )] 2 [Fe II (CN) 6 ](H 2 O) 2 }·10H 2 O (2), {[Cu 2 (L 2 )][Fe III (bpb)(CN) 2 ] 2 }·2H 2 O·2CH 3 OH (3) and {[Cu 2 (L 2 )] 3 [Fe III (CN) 6 ] 2 (H 2 O) 2 }·10H 2 O (4) have been synthesized by treating K[Fe III (bpb)(CN) 2 ] [bpb 2-=1,2-bis(pyridine-2-carboxamido)benzenate] and K 3 [Fe III (CN)] 6 with dinuclear compartmental macrocyclic Schiff-base complexes [CuPb(L 1 )] (ClO 4 ) 2 or [Cu 2 (L 2 )]·(ClO 4 ) 2 , in which H 2 L 1 was derived from 2,6-diformyl-4-methyl-phenol, ethylenediamine, and diethylenetriamine in the molar ratio of 2:1:1 and H 2 L 2 from 2,6-diformyl-4-methyl-phenol and propylenediamine in the molar ratio of 1:1. Single crystal X-ray diffraction analysis reveals that compound 1 displays a cyclic hexanuclear heterotrimetallic molecular structure with alternating [FeⅢ (bpb)(CN) 2 ]- and [CuPb(L 1 )] 2+ units. Complex 2 is of a neutral dumb-bell-type pentanuclear molecular configuration consisting of one [Fe(CN)6] 4- anion sandwiched in two [CuPu(L 1 )] 2+ cations, and the pentanuclear moieties are further connected by the hydrogen bonding to give a 2D supramolecular framework. Heterobimetallic complex 3 is a tetranuclear molecule composed of a centrosymmetric [Cu 2 (L2)] 2+ segment and two terminal cyanide-containing blocks [FeⅢ (bpb)(CN)2 ]- . Octanuclear compound 4 is built from two [Fe(CN)6]3- anions sandwiched in the three [Cu 2 L 2 ] 2+ cations. Investigation of their magnetic properties reveals the overall antiferromagnetic behavior in the series of complexes except 2.     

快速检测中药材中黄曲霉毒素B1的电化学生物传感器

结合新型纳米传感膜材料,以黄曲霉毒素Bl(AFBl)单克隆抗体为生物识别元件,通过考察AFB1与抗体之间的相互作用对测试底液中[Fe(CN)6]3-/[Fe(CN)6]4-([Fe(CN)6]3-/4-)氧化还原体系的影响,构建了一种可用于中药材中AFB1快速检测的电化学生物传感器.在最佳条件下,对AFB1浓度的线性响...     

聚谷氨酸修饰电极测定盐酸异丙肾上腺素

盐酸异丙肾上腺素( Isoprenaline Hydrochloride)是β肾上腺素受体激动药,有舒张支气管、改善心肌传导和扩张周围血管作用.目前,测定异丙肾上腺素的方法有高效液相色谱法[1,2]、毛细管区带电泳法[3]、化学发光法[4]和激光散斑法[5]等.     

两个基于[Fe(bpca)(CN)3]-的一维3d-4f异金属配合物的合成和晶体结构

以[(bpca)Fe(CN)3]-(bpca=二(2-吡啶羰基)酰胺阴离子)为构筑基元,设计合成了2个新颖的3d-4f异金属配合物,{[(bpca)Fe(CN)3Pr(H2O)5]Cl2}n(1)和{[(bpca)2Fe2(CN)6Pr(H2O)6]Cl·4H2O}n(2),并测定了它们的晶体结构.化合物1的晶体属正交晶系,Pnma空间群;而化合物2属三斜晶系,P1空间群.在这2个化合物中,[(bpca)Fe(CN)3]-和[Pr(H2O)x]3 (1,x=5;2,x=6)交替排列形成一维链状结构,并通过π-π堆积作用、氢键作用及分子间短距离相互作用形成三维网络结构.     

异丙隆分子印迹敏感膜传感器

在弱酸(pH 5.5)条件下,采用电聚合法在金电极上制备邻氨基酚异丙隆分子印迹膜,对该印迹膜的性能、分子印迹效应和印迹膜对模板分子及其结构相似物的选择性响应等进行了研究.以K3Fe(CN)6为印迹电极和底液间的探针,建立了一种检测异丙隆的方法.该传感器对异丙隆具有良好的选择性和敏感度,异丙隆浓度在1.0×10-7～4.0×10-4 mol/L范围内与K3Fe(CN)6还原峰电流减少量呈线性关系; 检出限为2.95×10-8 mol/L.对农田水中异丙隆含量进行了测定,回收率为99.0%～102.0%.     

流动注射-化学发光法测定药物中异丙肾上腺素

异丙肾上腺素属于儿茶酚胺类药物,临床广泛用于支气管哮喘、心脏骤停、房室阻滞以及抗休克等方面的治疗.测定异丙肾上腺素的分析方法文献报道主要有高效液相色谱法[1,2]、荧光法[3]、分光光度法[4,5]和核磁共振波谱法[6]等.     

碱性电解液中K3[Fe(CN)6]在锌阳极上的自发还原和吸附延长锌镍电池的循环寿命

采用K₃[Fe(CN)₆]作为锌镍电池的电解液添加剂,克服了锌阳极的变形。此外,通过一系列实验设计和表征,探索了电解液中金属锌与K₃[Fe(CN)₆]的反应机理。通过XRD (X-ray diffraction)和XPS (X-ray photo-electron spectroscopy)测试,我们发现金属锌在KOH水溶液中能够与K₃[Fe(CN)₆]反应,将[Fe(CN)₆]^3–还原为[Fe(CN)₆]⁴⁻。添加K₃[Fe(CN)₆]的锌镍电池实现了更长的循环寿命,比不添加K₃[Fe(CN)₆]的锌镍电池长3倍以上。在相同循环次数下,改性电解质中锌阳极循环不仅形状变化较小,而且没有出现“死”锌现象,电极添加剂和粘结剂也没有发生偏析。此外,不同于一般的有机添加剂,K₃[Fe(CN)₆]的加入不仅不会增大电极的极化,还能够提高锌镍电池的放电容量和倍率性能。因此,考虑到这一改性策略有着较高的可行性和较低的成本,K₃[Fe(CN)₆]添加剂在锌镍电池的实际应用中具有极大的推广潜力。     

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.