二氢蒽醌用于荧光猝灭法测定痕量汞

荧光动力学分析法常以罗丹明类、荧光素类、桑色素等作为指示物,用蒽醌作为指示物较少见。本文报道了以2,3二-氢-9,10二-羟基-1,4蒽-醌(R)为指示物,荧光动力学分析法测定痕量汞的新方法。直接用硼酸代替三氯化铝加硫酸封环一步法制得1,4二-羟基-9,10蒽-醌,再经冰醋酸和锌粉还原     

流动注射光纤动力学荧光法测定锰──锰-二元荧光配合物-高碘酸钠体系

对二元荧光配合物作为动力学反应指示剂的可行性进行了考察,以8-羟基喹啉-5-磺酸铝-高碘酸钠为指示反应,建立起流动注射光导纤维光谱技术测定痕量锰(Ⅱ)的动力学荧光分析新体系.此法线性范围为5～200ng/mL,检出限为1ng/mL,对50ng/mL锰(Ⅱ)进行11次测定的相对标准偏差为0.5%,分析速度为45样次/h.     

三种羟基蒽醌类药物与溶菌酶的作用及其构效关系研究

在模拟人体生理条件下,利用紫外光谱法、荧光光谱法和同步荧光光谱法结合研究三种羟基蒽醌类药物(1,2-二羟基蒽醌、1,4-二羟基蒽醌和1,8-二羟基蒽醌)与溶菌酶(LYSO)相互作用机制,并探讨其构效关系。紫外结果初步显示,三种羟基蒽醌类药物与LYSO发生相互作用。荧光结果进一步证实三种羟基蒽醌类药物均与LYSO发生结合,且对LYSO的荧光猝灭机制均为静态猝灭并伴随有非辐射能量转移。三种羟基蒽醌类药物与LYSO均存在一个结合位点,它们与LYSO形成1∶1复合物,在303K下,结合常数K分别为8.47×105、4.88×105和5.43×105L·mol-1,结合距离r分别为5.83、5.12和5.14nm,与溶菌酶作用后焓变分别为-41.2、-87.6和-39.0 kJ·mol-1,熵变分别为-22.4、-180和-19.1 J·mol-1·K-1。三种羟基蒽醌类药物与LYSO的作用力均为范德华力和氢键,且作用强弱不同,其顺序为:1,2-二羟基蒽醌1,8-二羟基蒽醌1,4-二羟基蒽醌。同步荧光法结果表明三种羟基蒽醌类药物与LYSO相互作用后均导致LYSO构象发生改变。研究结果表明,蒽醌环上羟基位置的不同对羟基蒽醌类药物与溶菌酶结合强弱有较大程度的影响。     

催化光度法测定痕量银

以过硫酸钾-有机还原剂体系催化动力学法测定银已有报道。但是,以α,α＇-联吡啶为活化剂,过硫酸钾氧化三苯甲烷类染料作为指示反应的催化动力学法测定银,报道甚少。曾研究了以邻苯二酚紫作为指示物质的催化反应。笔者也曾研究了二甲酚橙、依来铬青R和铬天青S等酸性三苯甲烷染料,均获得较满意结果。本文旨在对含羟基三苯甲烷染料进一步探讨。实验结果表明,以这类染料作为指示物     

征文通知

答：茜素络合剂（Alizarin Complexan）为羟基蒽醌类显色剂，是茜素（1，2-二羟基蒽醌）的衍生物，其化学名为二羧基甲氨甲基-1，2-二羟基蒽醌，或3-氨基-甲基茜素-N，N-二乙酸。由于其分子中含具有络合作用的亚甲基二乙酸，故俗称为茜素络合剂，其化学结构式如下：     

蒽醌丙烯酸酯、酰胺的合成

本文报道了3-羟基蒽醌-2-醛、1,6,8-三羟基蒽醌-3-醛、3-甲氧基蒽醌-2-醛、3-甲氧基蒽醌-2-丙烯酸及酯类、1,6,8-三羟基蒽醌-3-丙烯酸及蒽醌-2-丙烯酰胺类衍生物的合成,并报道有关化合物的紫外及红外吸收光谱数据。     

1,8-二羟基-9,10-二氢蒽的合成

以1,8-二羟基蒽醌为原料,经甲醚化,锌粉和金属钠还原,去甲基等4步反应合成1,8-二羟基-9,10-二氢蒽,总产率为37.1,8-二甲氧基蒽醌用NaBH₄/CF₃COOH还原生成二聚产物,并测定了其单晶结构.     

2-(2-羟基-5-氯苯基)-1H-苯并咪唑-铜(Ⅱ)配合物作为NO荧光探针的初探

常温下合成了2-(2-羟基-5-氯苯基)-1H-苯并咪唑荧光化合物和其二价铜离子的配合物,并对配合物的结构和稳定性进行了表征,用荧光光谱、质谱、红外光谱等研究了配合物与NO反应的机理.结果表明,该配合物与NO的反应具有高度的选择性,不受其他常见干扰分子的影响.配合物应用于脂多糖(LPS)激活的小鼠巨噬细胞中NO的测定,能够得到具有较好分辨率的荧光成像结果.     

催化H2O2氧化2, 3, 4, 9-四氢-9-羟基-1, 10-蒽醌荧光猝灭法测定痕量砷

基于HCl介质中和α,α-联吡啶存在下,As(V)可催化H2O2氧化2,3,4,9-四氢-9-羟基-1,10-蒽醌(R)转化无荧光化合物,导致体系荧光急剧猝灭,据此建立了催化H2O2氧化R荧光猝灭法测定痕量砷的新方法.在最佳条件下,As(V)含量在0.004 0~0.400 0 ng/mL范围内与荧光光强度的△If值符合比尔定律,工作曲线的回归方程△If=11.94 233.7 CAs(V)(ng/mL),n=7,相关系数r=0.9994,检出限为6.2×10-13g As(V)/mL,n=11.对0.004 0和0.400 0 ng/mL As(V)分别进行11次的测定,其RSD为2.6%与3.8%.该方法重现性好、灵敏、准确,用于实际中砷含量的测定,结果满意.还报道了R的合成,并借助核磁共振谱、红外光谱及质谱等谱学方法确定了其结构.     

N,N′,N″-三(2-羟基-1-萘酚醛)胺稀土配合物的合成及其荧光性能的初探

预先制备了N,N′,N″-三(2-羟基-1-萘酚醛)胺作为配体(L),然后向含配体L的乙醇-二氯甲烷溶液中加入含稀土硝酸盐晶体RE(NO3)3.6 H2O(RE=La3+,Sm3+,Y3+,Tb3+,Ce3+,Eu3+)的乙醇溶液,合成稀土配合物。利用核磁共振法、元素分析法、摩尔电导法、红外光谱法及差热-热重法对稀土配合物的结构进行表征。结果表明:稀土配合物的结构为RE(NO3)3.L.4 H2O。采用荧光技术对稀土配合物的性能进行了研究,结果表明:在pH值约为7的介质中,以二甲亚砜(DMSO)为溶剂,稀土配合物浓度为1.0×10-4mol.L-1时,铽(Ⅲ)配合物有较强的特征荧光发射,铕(Ⅲ)配合物只表现了微弱的特征荧光发射,其他稀土配合物没有特征荧光发射。     

Sc2MgGa2 and Y2MgGa2

Scandium magnesium gallide, Sc₂MgGa₂, and yttrium magnesium gallide, Y₂MgGa₂, were synthesized from the corresponding elements by heating under an argon atmosphere in an induction furnace. These intermetallic compounds crystallize in the tetragonal Mo₂FeB₂‐type structure. All three crystallographically unique atoms occupy special positions and the site symmetries of (Sc/Y, Ga) and Mg are m2m and 4/m, respectively. The coordinations around Sc/Y, Mg and Ga are pentagonal (Sc/Y), tetragonal (Mg) and triangular (Ga) prisms, with four (Mg) or three (Ga) additional capping atoms leading to the coordination numbers [10], [8+4] and [6+3], respectively. The crystal structure of Sc₂MgGa₂ was determined from single‐crystal diffraction intensities and the isostructural Y₂MgGa₂ was identified from powder diffraction data.     

Electrochemical study of (NEt4)2Cl2FeS2MoS2 and (NEt4)2Cl2FeS2MoS2FeCl2

Summary The ability of [MoS₄]^2–, anions to be used as ligands for transition metal ions has been widely demonstrated, especially with Fe²⁺. The present study has been restricted to linear complexes such as (NEt₄)₂ [Cl₂FeS₂MoS₂] and (NEt₄)₂[Cl₂FeS₂MoS₂FeCl₂]. Their electrochemical properties are described: upon electrochemical reduction, these compounds yield MoS₂, as a black precipitate, and an iron complex in solution, assumed to be [SFeCl₂]^2–. The electrochemical reduction goes through two electron transfers, coupled with the breakdown of the molecular skeleton: a DISPl and an ECE mechanism. Depending on the solvent, the following equilibrium may be observed: [Cl₄Fe₂MoS₄]^2–[Cl₂FeMoS₄]^2–+FeCl₂. The equilibrium constant, K_D, was evaluated by differential pulse polarography. K_D is tightly related to the donor number of the solvent.     

The alkali hypophosphites KH2PO2, RbH2PO2 and CsH2PO2

The structures of the hypophosphites KH₂PO₂ (potassium hypophosphite), RbH₂PO₂ (rubidium hypophosphite) and CsH₂PO₂ (caesium hypophosphite) have been determined by single‐crystal X‐ray diffraction. The structures consist of layers of alkali cations and hypophosphite anions, with the latter bridging four cations within the same layer. The Rb and Cs hypophosphites are isomorphous.     

Zur Kenntnis der Dialkalimetalldichalkogenide β-Na2S2, K2S2, α-Rb2S2, β-Rb2S2, K2Se2, Rb2Se2, α-K2Te2, β-K2Te2 und Rb2Te2

On Dialkali Metal Dichalcogenides β-Na₂S₂, K₂S₂, α-Rb₂S₂, β-Rb₂S₂, K₂Se₂, Rb₂Se₂, α-K₂Te₂, β-K₂Te₂ and Rb₂Te₂ The first presentation of pure samples of α- and β-Rb₂S₂, α- and β-K₂Te₂, and Rb₂Te₂ is described. Using single crystals of K₂S₂ and K₂Se₂, received by ammonothermal synthesis, the structure of the Na₂O₂ type and by using single crystals of β-Na₂S₂ and β-K₂Te₂ the Li₂O₂ type structure will be refined. By combined investigations with temperature-dependent Guinier-, neutron diffraction-, thermal analysis, and Raman-spectroscopy the nature of the monotropic phase transition from the Na₂O₂ type to the Li₂O₂ type will be explained by means of the examples α-/β-Na₂S₂ and α-/β-K₂Te₂. A further case of dimorphic condition as well as the monotropic phase transition of α- and β-Rb₂S₂ is presented. The existing areas of the structure fields of the dialkali metal dichalcogenides are limited by the model of the polar covalence.     

Formal [(2+2)+2] and [(2+2)+(2+2)] nonconjugated dienediyne cascade cycloadditions

[reaction: see text] Fluoranthene 2 and heptacycle 3 are easily accessible from the reaction of diyne 1 and norbornadiene (NBD) in the presence of the rhodium catalyst. The unusual [(2+2)+(2+2)] adduct 3 was confirmed by the X-ray crystal structure analysis.     

Crystal Structures of [Bu2Sn(O2PPh2)2], [Ph2Sn(O2PPh2)2], and [PhClSn(O2PPh2)OMe]2. Raman Spectra of [Ph2Sn(O2PPh2)2] and [PhClSn(O2PPh2)OMe]2

[(n‐Bu)₂Sn(O₂PPh₂)₂] ( 1 ), and [Ph₂Sn(O₂PPh₂)₂] ( 2 ) have been synthesized by the reactions of R₂SnCl₂ (R=n‐Bu, Ph) with HO₂PPh₂ in Methanol. From the reaction of Ph₂SnCl₂ with diphenylphosphinic acid a third product [PhClSn(O₂PPh₂)OMe]₂ ( 3 ) could be isolated. X‐ray diffraction studies show 1 to crystallize in the monoclinic space group P2₁/c with a = 1303.7(1) pm, b = 2286.9(2) pm, c = 1063.1(1) pm, β = 94.383(6)°, and Z = 4. 2 crystallizes triclinic in the space group , the cell parameters being a = 1293.2(2) pm, b = 1478.5(4) pm, c = 1507.2(3) pm, α = 98.86(3)°, β = 109.63(2)°, γ = 114.88(2)°, and Z = 2. Both compounds form arrays of eight‐membered rings (SnOPO)₂ linked at the tin atoms to form chains of infinite length. The dimer 3 consists of a like ring, in which the tin atoms are bridged by methoxo groups. It crystallizes triclinic in space group with a = 946.4(1) pm, b = 963.7(1) pm, c = 1174.2(1) pm, α = 82.495(6)°, β = 66.451(6)°, γ = 74.922(6)°, and Z = 1 for the dimer. The Raman spectra of 2 and 3 are given and discussed.     

Die Photoionenspektren von SCl2, S2Cl2 und S2Br2

Photoionization Mass Spectra of SCl₂, S₂Cl₂, and S₂Br₂ Photoionization mass spectra of SCl₂, S₂Cl₂, and S₂Br₂ have been measured. Heats of formation, bond energies, and ionization potentials of fragments have been calculated from appearance potentials.