溶胶-凝胶-钴-邻菲啰啉修饰电极对一氧化氮的电催化氧化及其测定

报道了溶胶 凝胶 钴 邻菲口罗啉膜修饰电极的制备方法及其在一氧化氮(NO)检测中的应用,采用循环伏安法(CV)研究修饰电极的电化学特性,差示脉冲伏安法(DPV)对NO进行检测。该修饰电极对NO的电化学氧化具有很好的催化作用,使其氧化电位负移了210mV,氧化峰电流与NO浓度在5.6×10-8～2.8×10-5mol/L范围内呈良好的线性关系,相关系数r=0.999,检测限为1.4×10-8mol/L,且生物体内常见的干扰物质如抗坏血酸、NO2-和儿茶酚胺类神经递质的代谢物等不干扰测定。     

在线氧化还原流动注射分光光度法测定多贝斯

建立了在线氧化还原流动注射分光光度法测定多贝斯的新方法。研究了多贝斯与Fe3 + 的反应摩尔比和各种影响因素 ,发现Fe3 + 可以定量氧化多贝斯。产生的Fe2 + 与邻菲咯啉在弱酸性介质中生成稳定的红色络合物 ,该络合物在 5 12nm处的最大吸收与多贝斯浓度在 4 .2 4× 10 -6～ 4 .6 6× 10 -5mol/L范围内呈线性关系。回归系数为 0 .9987;方法的检出限为 5 .3× 10 -7mol/L ;相对标准偏差为 0 .5 % (n =8) ;采样率为 30次/h。     

一种测定·OH产生与清除的新化学发光体系

报道一种产生和检测·OH的新化学发光体系。该体系由50μL2.0mmol/LCuCl,50μL1 %(φ)H2O2,50μL1.5mmol/L邻菲啉,0.05mol/LNa2CO3-NaHCO3 缓冲液(pH9.60)组成,反应液总体积为1.0mL。该体系简便、稳定、灵敏、特异性强,值得推广。     

磷酸盐缓冲溶液对邻二氮菲-Fe2+氧化法测定羟基自由基的影响

考察了不同浓度、不同体积的pH=7.4磷酸盐缓冲溶液对邻二氮菲-Fe2+氧化法检测羟基自由基体系的影响.将pH=7.4,浓度分别为0.1,0.15和0.2mol/L的磷酸盐缓冲溶液加入邻二氮菲-Fe2+体系中,随着各自缓冲溶液加入量的增加,其ΔA536不断减小,当加入量超过3mL时,ΔA536基本保持不变.采用抗坏血酸清除含有不同浓度磷酸盐缓冲溶液的邻二氮菲-Fe2+体系,实验结果表明,缓冲溶液浓度和加入量的不同,对于测定体系中清除羟基自由基的作用结果有影响.因此,邻二氮菲-Fe2+氧化法测定羟基自由基需明确体系中磷酸盐缓冲溶液的浓度及用量,在明确的统一体系中,才能进行有效的比较.     

磷酸氯喹与过氧化氢缔合催化作用的极谱研究

在2.0×10-2mol/LNH3·H2O NH4Cl(pH9.5)-1.0×10-2mol/LH2O2支持电解质中,磷酸氯喹于-1.87V(vs.SCE)产生一缔合平行催化波。该波的二阶导数峰峰电流与磷酸氯喹浓度在2.0×10-9～1.0×10-5mol/L范围内呈线性关系(r=0.9986,n=10)。可用于片剂中磷酸氯喹的测定。H2O2有双重作用:(1)H2O2作为配位体与磷酸氯喹形成缔合物,使峰电位Ep负移;(2)H2O2作为氧化剂氧化磷酸氯喹经单电子单质子还原生成的中间体自由基,产生极谱催化波。     

极谱催化波法测定马蔺子素

报道了在Na2 B4 O7 KH2 PO4 K2 S2 O8体系中马蔺子素的极谱催化波。拟定了测定马蔺子素的新方法。在 8.0× 10 - 3mol/LNa2 B4 O7 1.6× 10 - 2 mol/LKH2 PO4 (pH =7.7) 5 .0× 10 - 3mol/LK2 S2 O8底液中 ,极谱催化波峰电位Ep=-1.2 3V(vs .SCE) ;二阶导数峰峰电流i″p 与马蔺子素浓度在 2 .0× 10 - 9～ 2 .0× 10 - 6 mol/L范围内呈良好线性关系 ,检出限为 1.0× 10 - 9mol/L。催化波灵敏度比相应马蔺子素还原波高 75倍。采用该法测定了胶囊中马蔺子素的含量     

稀土苯丙氨酸邻菲咯啉三元配合物的合成、表征及抗菌活性研究

以稀土氯化物、L-苯丙氨酸和邻菲咯啉为原料,在乙醇水溶液中反应,制备了一类新型稀土三元配合物。通过元素分析、摩尔电导、红外光谱、拉曼光谱、紫外光谱和热重-差热分析,确定了该配合物的化学组成:RE(Phe)3PhenCl3.3H2O(RE=La3+,Ce3+,Pr3+,Nd3+,Sm3+,Eu3+,Er3+,Y3+;Phe=L-苯丙氨酸;phen=邻菲咯啉)。通过抗菌实验对其抑菌效果进行研究。结果表明,稀土三元配合物对大肠杆菌、金黄色葡萄球菌和白色念珠菌有较强的抑制作用(最小抑菌浓度MIC分别约为65×10-4%,150×10-4%,400×10-4%),属于广谱抗菌剂;抗菌效果明显优于稀土氯化物、L-苯丙氨酸或邻菲咯啉。     

电泳中介微分析法测定铁(Ⅱ)和铜(Ⅱ)

利用电泳中介微分析通过与邻菲罗啉的络合反应完成了对Fe2+与Cu2+的同时测定。在压差作用下,淌度较小的邻菲罗啉在金属离子区带之前首先进样,加高电压后,两区带电泳在磷酸缓冲液中 (pH=4. 5)混合、反应形成络合物并实现电泳分离。研究了缓冲液pH、试剂和样品区带长度对分离效果的影响。对于Fe2+与Cu2+两离子,方法的检出限(S/N=3)分别为 1. 6和 11μmol/L;线性范围分别为 5. 0×10-6 ~3. 0×10-4 mol/L(r=0. 9979)和 8. 0×10-5 ~3. 0×10-4 mol/L(r=0. 9996)。采用标准矿样验证了测定Fe2+的可行性。     

In(Ⅲ) -NCP体系配位吸附波研究及应用

在0.15 mol/L HAc-NaAc(pH 3.2)介质中,In(Ⅲ)-NCP(2,9-二甲基邻菲咯啉)配合物在2.5次微分极谱图上产生良好的吸附还原波.其峰电位为-0.40 V,峰电流与In(Ⅲ)浓度在4.0×10-8～2.0×10-6 mol/L范围内呈良好的线性关系,检出限为8.0×10-9 mol/L.应用该法测定了氢氧化铝和陶瓷颜料中的微量铟,结果满意.研究了配合物的组成、极谱波的性质及其机理.     

1,10-邻菲啰啉-5,6-二酮修饰碳糊电极测定水中镉

以1,10-邻菲啰啉-5,6-二酮(phendio)修饰碳糊电极为工作电极,在0.05mol/L HAc-NaAc(pH4.74)电解液中,于-1.30V(vs.SCE)处Cd2 以Cd-1,10-邻菲啰啉-5,6-二酮络合物的形式吸附到电极上,再经过阳极溶出,从而建立了一种测定水样中痕量镉的新方法。本法于-0.69V处产生一个灵敏的溶出峰,其二阶导数峰电流与Cd2 的浓度在2.4×10-7~6.0×10-9mol/L范围内呈良好的线性关系;检出限为3.0×10-10mol/L(S/N=3)。应用本方法测定水样中的Cd2 ,结果令人满意。     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.     

Facile synthesis of bicyclic 1-arylpyrazol-5-ones

In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.     

Synthesis of pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles by Curtius reaction in Morita-Baylis-Hillman derivatives

Synthesis of substituted pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles from the Morita-Baylis-Hillman derivatives of acrylates via saponification followed by Curtius reaction is described.     

正丁胺对激光染料荧光谱影响的研究

用正丁胺作为碳源,采用射频辉光放电制备碳膜,选用激光染料R6G和聚乙二醇混合液作为蒸气源,采用单源热蒸发,在蒸发室与染料同时沉积得到混合膜,用拉曼光谱和红外光谱分析了碳膜的结构和键合方式,分析表明:碳膜中存在胺基团和氢原子.混合膜的荧光谱测量结果表明,认为正丁胺对染料荧光谱的影响是因为胺基和氢原子的存在.     

Cu0-catalysed 1,3-dipolar cycloadditions of α-amino acid derived N,N-cyclic azomethine imines to ynones

A series of 20 CuAIAC reactions between eight 4-acylamino substituted pyrazolidine-3-one-1-azomethine imines and four terminal ynones were performed using Cu⁰ as catalyst. The corresponding fluorescent cycloadducts were obtained in very high yields upon simple workup. Thus, Cu-metal turned out to be a better catalyst than Cu^I in terms of yield and ease of isolation. Availability of azomethine imines, mild reaction conditions, and simple workup enable a “click” access to libraries of densely substituted 2,3-dihydro-1H,5H-pyrazolo[1,2-a]pyrazol-1-ones. Reactivity of differently substituted dipoles was evaluated experimentally and by quantum chemical methods (DFT).     

Synthesis and antioxidative/anti-inflammatory activity of novel fullerene–polyamine conjugates

(E)-4-(Fullerenopyrrolidin-1-yl)-3-methylbut-2-enoic acid and its corresponding succinimidyl ester, readily obtained through Prato-type modification of C₆₀, were used for the selective N-acylation of polyamines. The thus obtained conjugates were evaluated for their antioxidative and anti-inflammatory activity and their cytotoxicity was determined. Members of this family of compounds showed interesting anti-lipid peroxidation, anti-lipoxygenase and anti-inflammatory activity and comparable cytocompatibility to spermidine.