Spectrofluorimetric Determination of Magnesium (Ⅱ) with 7-(8-Hydroxy-3, 6-Disulfonaphthylazo)-8-Hydroxyquinoline-5-Sulfonic Acid

A new fluorescent reagent, 7 (8 hydroxy 3, 6 disulfonaphthylazo) 8 hydroxyquinoline 5 sulfonic acid (HDNHQ) for the determination of magnesium has been developed. It reacted with magnesium to form a 1∶1 fluorescent complex with λ ex / λ em =356/495 nm immediately at room temperature in ammonia ammonium chloride buffer (pH 10.7). A linear relationship was obtained in the magnesium concentration range of 0 160 ng·mL -1 with the detection limit of 0.04 ng·mL -1 . The proposed method was simple, rapid and sensitive. It has been successfully applied to the determination of trace magnesium in blood serum with recoveries of 103.75% and 98.16%, respectively.

Hydrothermal Syntheses and Crystal Structures of Six Complexes Constructed from 1,3,5-Benzenetricarboxylic Acid and 4'-(4-Pyridyl)-2,2':6',2''-terpyridine Mixed Ligands

Six new transition metal complexes, [Zn（HBTC）（PYTPY）]n·n PYTPY（1）, [Cu（HBTC）（PYTPY）]n·n PYTPY（2）, [Co（HBTC）（PYTPY）]n·n DMF（3）, [Mn（HBTC）（PYTPY）]n·n DMF（4）, [Cd（HBTC）（PYTPY）（H2O）]n·2nH2O（5）, and [Co（HBTC）（PYTPY）（H2O）2]（6）,（H3BTC = 1,3,5-benzenetricarboxylic acid, PYTPY = 4＇-（4-pyridyl）-2,2＇：6＇,2＇＇-terpyridine, DMF = N,N？-dimethylformamide）, have been synthesized and characterized by elemental analysis, IR and X-ray single-crystal diffraction. Complexes 1~5 all feature one-dimensional chain structures, and complex 6 exhibits a zero-dimensional structure. Complexes 1~5 present three-dimensional（3D） supramolecular frameworks via π-π stacking interactions, whenas 6 has also a 3D supramolecular structure assembled by hydrogen bonding. Meanwhile, complexes 1 ~ 6 exhibit the thermal stabilities and photoluminescent properties.

pH Dependent Supramolecules Based on Co-crystallization of Pyrazine-2,3,5,6-tetracarboxylic Acid with 4,4＇-Bipyridine through Intermolecular Hydrogen Bonds

Co-crystallization of pztcH_4 with 4,4＇-bipyridine（4,4＇-bipy） in pH = 3-4 and 1-2 gave two new binary molecular adducts： [（4,4＇-bipy H2）（pztc H2）]（1） and [（4,4＇-bipy H2）（pztcH3）（Cl）]·4H2O（2）, respectively. Compounds 1 and 2 have been characterized by IR, elemental analysis, NMR and X-ray single-crystal diffraction. Compound 1 crystallizes in triclinic, space group P1 with a = 5.7752（12）, b = 7.9126（16）, c = 9.4492（19） ？, α = 97.49（3）, β = 107.71（3）, γ = 94.52（3）o, V = 404.62（14） A^3, Z = 1, μ = 0.137 mm^1, Dc = 1.692 Mg/m^3, C18H12N4O8, Mr = 412.32, F（000） = 212, S = 1.025, R = 0.0360 and wR = 0.0973. Compound 2 crystallizes in monoclinic, space group C2/c with a = 17.093（3）, b = 7.7665（16）, c = 18.414（4） A, β = 113.36（3）o, V = 2244.1（8） A^3, Z = 4, μ = 0.244 mm^-1, Dc = 1.542 Mg/m^3, C18H21ClN4O12, Mr = 520.84, F（000） = 1080, S = 1.021, R = 0.0343 and wR = 0.0978. In compound 1, pztc H22- anions self-formed 2-D sheets by strong Oacid-H···Oacidhydrogen bonds, which are further extended to form a 3-D supramolecular network bridged with 4,4？-bipy via N-H···Oacid interactions. In compound 2, besides the 1-D chain constructed by pztc H3-itself through strong H-bond Oacid-H···Oacid, the other chain is constructed with 4,4？-bipy H22＋, Cl-anion and water molecules by moderate H-bonds and Ow-H···Cl and N-H···Ow. The two chains are linked with μ3-connected water molecules resulting from the combination of strong synthon-assisted H-bonding Oacid-H···Ow to afford an interlaced 3-D network.

A Lanthanide-transition Metal Coordination Polymer:{[CuEu(Hbidc)_2(H_2O)_4]·H_2O}_n(H_3bidc=1H-benzimidazole-5,6-dicarboxylic Acid)

The title complex 1,{[CuEu（Hbidc）2（H2O）4]·H2O}n（H3bidc = 1H-benzimidazole-5,6-dicarboxylic acid）,has been solvothermally synthesized and structurally characterized by single-crystal X-ray diffraction.Complex 1 crystallizes in triclinic,space group P1,with a = 7.791（2）,b = 12.058（3）,c = 12.109（3）,α = 82.189（5）,β = 72.407（5）,γ = 89.184（4）°,V = 1073.7（5）3,C18H18CuEuN4O13,Mr = 713.86,Dc = 2.208 g/cm3,μ（MoKα） = 3.967 mm-1,F（000） = 700,GOOF = 0.950,Z = 2,the final R = 0.0531 and wR = 0.1068 for I 2σ（I）.Complex 1 possess a tape-like chain structure consisting of Eu2C8O4 and Cu2Eu2C18N4O4 metallic rings alternatively arranged and is the first 3d-4f heterometallic complex based on the 1H-ben-zimidazole-5,6-dicarboxylato ligand（Hbidc）.Plenty of hydrogen-bonding and π...π stacking interactions connect the 1D chains to construct a 3D supramolecular architecture.

Structure and Photoluminescence of a 3D Coordination Polymer from Triazole and 2,6-Dimethylpyridine-3,5-dicarboxylic Acid

A new metal-organic coordination polymer [Zn2（trz）2（mpda）（H2O）]n（1, trz = 1,2,4-triazole, H2 mpda = 2,6-dimethylpyridine-3,5-dicarboxylic acid） was synthesized and characterized by single-crystal X-ray analyses. The crystal is of monoclinic system, space group P21/n, a = 9.619（3）, b = 8.920（3）, c = 22.159（6）, β = 96.897（4）°, V = 1887.3（9）3, Z = 4, Mr = 478.04, D3 c = 1.682 Mg/m, F（000） = 960, the final R = 0.0264 and wR = 0.0870（I 2σ（I））. Compound 1 consists of {[Zn4（trz）4]4＋}n layers, which are further connected by mpda2- to complete a three-dimensional structure. The title compound exhibits luminescence at λmax = 415 nm upon excitation at 364 nm.

STEREOCHEMISTRY OF THE BENZILIC ACID-TYPE REARRANGEMENT IN BASE-CATALYZED AUTOXIDATION OF 3α,5-CYCLO-5α-CHOLESTANE-6-ONE

The configuration of the hydroxy acid 2, a product from base-catalyzed autoxidation of 3α,5-cyclo-5α-cholestane-6-one,was established on the basis of NMR techniques and the mechanism of the formation of 2 was discussed.

Synthesis and Characterization of Some Transition Metal Chelates of 5-(1-Hydroxy-6-Naphthylazo-3-Sodium Sulphonate) Thiobarbituric (L_1) and Barbituric (L_2) Acids

Some transition metal chelates of two ligands L1 and L2 were prepared and characterized by elemental analysis. The IR and 1H NMR spectra of several chelates of two ligands L1 and L2 showed the involvement of the azo group in chelation with the transition metaI ions, in most of the studied chelates, and that the two ligands L1 and L2 showed the involvement of the azo group in chelation with the transition metal ions, in most of the studied chelates, and that the two ligands L1 and L2 were coordinated either in the enol or the keto form. IR spetra also showed that Fe(III)-, Ni(II)-, Mn(II)-, VO(II)-L1 and Cu(II)-L2 chelates behaved in a bidentate manner, in contrast with the two (1:1) M:L cobalt chelates with the two ligands are tridentate.TG analysis indicated the presence of three to twelve water molecules of hydration eliminated on heating up to 150℃ and one or two coordinated water molecules removed at 150~180℃.The octahedral structure is proposed fOr all the chelates, except Cu(II)-L2 and Ni(II)-L1 chelates which have square planar geometry, based on their electronic spectra

Synthesis and Molecular Structure of Acetic Acid-3,5-diacetoxy-2-acetoxymethyl-6-(4-quinoxalin-2-yl-phenoxy)-tetrahydro-pyran-4-yl-ester

The title compound, acetic acid-3,5-diacetoxy-2-acetoxymethyl-6-（4-quinoxalin- 2-yl-phenoxy）-tetrahydro-pyran-4-yl-ester 8 （C28H28N2O10, Mr = 552.54）, has been synthesized and its crystal structure was determined by X-ray diffraction analysis. It crystallizes in monoclinic, space group P21, a = 10.060（8）, b = 5.648（4）, c = 24.11（2）A, β = 91.078（10）°, Z = 2, V= 1369.9（19）A^3, Dc = 1.339 g/cm^3,μ（MoKa） = 1.03 cm^-1, F（000） = 580.00, T =. 193.1 Kx-9 θmax = 25.03, （△/σ）max = 0.0000, Flack = -0.0（24）, the final R = 0.0680 and wR = 0.140 （w = 1/[0.0016Fo^2 ＋ 1.00000（Fo^2）]/（4Fo^2）） for 3126 observed reflections （1 〉 20（/））. The pyranoid ring adopts chair conformation in the sugar moiety, and all of the acetyl groups are in the e bond of the pyranoid ring, so the sugar moiety is very stable.

6-溴-5-羟基吲哚-3-羧酸酯类衍生物的合成及其抗病毒活性

目的设计合成 6 溴 5 羟基吲哚 3 羧酸酯类衍生物 ,并对其体外抗呼吸道病毒活性进行初步评价。方法以对苯醌、3 乙氨基 2 丁烯酸乙酯为起始原料 ,经多步反应合成目标化合物 ;并在MDCK和HeLa细胞内 ,采用细胞病变法 ,检测目标化合物对甲 3型流感病毒和呼吸道合胞病毒的抑制作用。结果与结论共制得 1 2个新化合物 ,经1H NMR、MS确证其结构。体外试验表明 ,目标化合物具有不同的抗病毒活性 ,其中Ⅵj 的体外抗病毒作用与阳性对照药金刚烷胺相当。

α-溴-2、3、4、5、6五氟甲苯衍生气相色谱同时测定吲-3-乙酸和脱落酸

用α-溴-2、3、4、5、6五氟甲苯作衍生剂,在55℃反应90分钟可与吲哚-3-乙酸和脱落酸生成酯。这两种酯可用气相色谱分离,电子捕获检测器测定。本方法操作简单、灵敏度高。最小检测量:吲哚-3-乙酸和脱落酸分别为10^(-14)g 和10^(-13)g。

一类新偶氮试剂的研究——Ⅱ.试剂2-(8′-羟基喹啉-5′-磺基-7′-偶氮)-1-羟基-8-氨基萘-3,6-二磺酸光度法测定铁(Ⅲ)

用新合成的偶氮试剂2-(8′-羟基喹啉-5′-磺基-7′-偶氮)-1-羟基-8-氨基萘-3,6-二磺酸(HQSAH)研究了光度法测定Fe(Ⅲ)的反应条件。Fe(Ⅲ)与试剂在pH4.66(NaAc/HAc缓冲介质)时发生特效络合反应,络合物吸收峰716nm,ε为1.64×10~4L·mol^(-1)cm^(-1),络合比为1:2(M:R),线性范围为0～20μg/25ml,检测限为5.0ng/ml,考察了其它共存离子的干扰,发现除Al(Ⅲ)略有干扰外,其它常见离子均允许大量存在,该方法已直接应用于血样、矿祥和铝合金样中铁的分析,结果令人满意。

2,6-二氯-5-氟-3-甲酸吡啶的合成

以氟乙酸乙酯、甲酸乙酯和氰基乙酰胺为原料,在甲醇钠的催化下经环化得到2,6-二羟基-5-氟-3-氰基吡啶,然后经PCl5/POCl3氯化和水解得到了标题化合物,总收率43.7%。

二甲基亚砜体系中2,3,5,6-四氟对苯二甲酸脱羧过程研究

采用二甲基亚砜(DMSO)为脱羧溶剂对2,3,5,6-四氟对苯二甲酸进行脱羧,分别考察温度、反应物浓度、时间各因素对反应的影响,结果表明,反应温度、反应物浓度对脱羧反应速率影响较大,控制反应时间均可获得较高的2,3,5,6-四氟苯甲酸收率。通过与其它芳香酸脱羧比较发现,不同取代结构的芳香羧酸的脱羧速率随吸电子基的结构与数量变化而变化。脱羧速率为:2,3,5,6-四氟对苯二甲酸>2,3,5,6-四氟苯甲酸,2,3,5,6-四氟对苯二甲酸>2,3,5,6-四氯苯甲酸>对苯二甲酸。

7-氨基-6-氰基-5-(3-硝基苯基)吡喃并嘧啶-2,4-二酮的合成

报道了常温、超声辐射、水中、无催化剂条件下,以3-硝基苯甲醛、丙二腈和巴比妥酸为原料合成标题化合物的方法。考察了超声技术、反应时间及反应温度对反应的影响。最佳反应条件为:室温、超声辐射2h,收率为86.2%。

4-(9-蒽基)-6-辛氧基-1,3,5-三嗪-2-胺的合成及其在酸性介质中的光谱行为研究

以2,4-二氯-6-辛氧基-1,3,5-三嗪为原料,经Kumada偶联及胺化两步反应合成了三嗪胺衍生物:4-(9-蒽基)-6-辛氧基-1,3,5-三嗪-2-胺(AOOTA),总产率为38%.通过紫外-可见吸收光谱及荧光光谱研究了氯仿溶液中AOOTA在乙酸(HOAc)及三氟乙酸(TFA)作用下的光谱行为.研究发现AOOTA与HOAc在基态及激发态下均不能发生双氢键作用,而AOOTA与TFA相互作用基态下形成双氢键复合物,激发态下由于分子中蒽基及辛氧基与三嗪环间的C—C单键以及C—O单键的自由旋转,从而使得AOOTA与TFA分子间不能形成有效的氢键相互作用.

新显色剂3-[(对羧基苯)偶氮]-6-[(5-羧基-1,3,4-三氮唑)偶氮]-变色酸的合成及与铜显色反应的研究

研究了新显色剂3-[(对羧基苯)偶氮]-6-[(5-羧基-1,3,4三氮唑)偶氮]-变色酸(CPCTZCA)的合成及与铜显色反应的条件。结果表明,在pH9.0的NH3-NH4Cl的缓冲溶液中,铜(II)与CPCTZCA形成配合比为1:2的稳定的蓝紫色配合物,其最大吸收波长在655nm处,表观摩尔吸光系数为1.4×104(L.mol-1.cm-1),Cu2+质量分数在(0～20)μg/25mL范围内服从比尔定律。所拟方法可不经分离直接测定镁合金、铝合金标样中的微量铜,结果与认定值相符。

7-氨基-6-芳基偶氮-5-羟基吡唑[1,5-a]并嘧啶-3-甲酸乙酯的合成

以氰乙酸乙酯和原甲酸三乙酯为原料,经过缩合、肼解、关环、重氮化及偶合等反应合成了13个新型的嘌呤类似物7-氨基-6-芳基偶氮-5-羟基吡唑[1,5-a]并嘧啶-3-甲酸乙酯(5a-5m)。通过IR、~1H NMR、MS和元素分析确定了所得化合物的结构。

6-甲基-5-硝基-3-吡啶硼酸频哪酯合成工艺的改进

以2-氯-3-硝基-5-溴吡啶为起始原料,经取代反应、水解反应、Suzuki偶联反应得到6-甲基-5-硝基-3-吡啶硼酸频哪酯。反应总收率为51%,中间体及目标产物结构由IR和1H-NMR表征。

(3R,5R)-3,5-二羟基-6-取代己酸不对称合成研究进展

概述近 2 0年来 ( 3R ,5R) 3 ,5 二羟基 6 取代己酸不对称合成进展 ,并提出其研究方向 .

6-溴-2-溴甲基-5-羟基-1-甲基吲哚-3-羧酸乙酯的合成工艺研究

采用5-乙酰氧基-1,2-二甲基吲哚-3-羧酸乙酯和溴素为原料,于四氯化碳中,在过氧化苯甲酰催化下,合成6-溴-2-溴甲基-5-羟基-1-甲基吲哚-3-羧酸乙酯,HPLC进行跟踪检测。采用正交设计研究确定了最佳合成工艺参数为:物料比1为n(5-乙酰氧基-1,2-二甲基吲哚-3-羧酸乙酯)∶n(四氯化碳)=1∶18.3,物料比2为n(5-乙酰氧基-1,2-二甲基吲哚-3-羧酸乙酯)∶n(溴素)=1∶2.84,反应时间5 h,反应温度45℃。在最佳条件下收率为84.6%,纯度为98%以上,达到了优化的目的。