离子缔合物二级散射光谱的分析应用: 硒(IV)-碘化物-罗丹明B体系

从硒(IV)-碘化物-罗丹明B反应体系的研究中, 发现了离子缔合物水溶液的两种二级散射光谱现象。研究了它们的光谱特征、影响因素和适宜条件, 确定了二级散射强度与溶液中离子缔合物浓度的关系, 提出了利用二级散射光谱测定痕量硒的高灵敏分析方法。对反应机理和二级散射变化的原因也进行了初步的探讨。     

离子缔合物二级散射光谱的分析应用: 硒(IV)-碘化物-罗丹明B体系

从硒(IV)-碘化物-罗丹明B反应体系的研究中, 发现了离子缔合物水溶液的两种二级散射光谱现象。研究了它们的光谱特征、影响因素和适宜条件, 确定了二级散射强度与溶液中离子缔合物浓度的关系, 提出了利用二级散射光谱测定痕量硒的高灵敏分析方法。对反应机理和二级散射变化的原因也进行了初步的探讨。     

离子缔合物二级散射光谱的分析应用——Ⅱ.汞(Ⅱ)-硫氰酸盐-碱性三芳基甲烷染料体系

研究了[Hg(SCN)_4]~(2-)与结晶紫、孔雀石绿、亮绿或碘绿等碱性三芳基甲烷染料的离子缔合配合物的二级散射(DS)和“反二级散射”(ADS)光谱,以及这类散射光谱的特征、影响因素和反应的适宜条件.确定了散射光强度与溶液中汞(Ⅱ)浓度的关系.提出了用二级散射光谱测定痕量汞的新的高灵敏分析方法,并对反应机理和两种二级散射发生变化的原因作了初步的讨论.     

离子缔合物二级散射光谱的分析应用——Ⅰ.硒(Ⅳ)-碘化物-罗丹明B体系

从硒(Ⅳ)-碘化物-罗丹明B反应体系的研究中,发现了离子缔合物水溶液的两种二级散射光谱现象.研究了它们的光谱特征、影响因素和适宜条件,确定了二级散射强度与溶液中离子缔合物浓度的关系,提出了利用二级散射光谱测定痕量硒的高灵敏分析方法.对反应机理和二级散射变化的原因也进行了初步的探讨     

烟碱-磷钼杂多酸缔合微粒体系的光谱研究及分析应用

采用分光光度法和共振散射光谱法研究了小烟碱一磷钼杂多酸缔合微粒体系．在波长300～800nm范围内,波长愈短缔合微粒体系的吸光度值愈大,在400nm处的吸光度与烟碱浓度在0．50-50．0μg／mL范围成良好线性关系,检出限(3σ)为0．1μg／mL．据此建立了一个测定烟草中烟碱含量的分光光度法．该法灵敏、简便、快速、准确、重复性好,平均回收率为99％～103％,相对标准偏差RSD为0．9％～1．3％．共振散射光谱研究结果表明,该体系存在烟碱-磷钼杂多酸缔合微粒,该微粒在420nm处存在共振散射效应．     

汞(Ⅱ)-硫氰酸盐-维多利亚蓝4R体系的共振发光和二级散射光谱及其分析应用

研究了[Hg(SCN)₄]^-配阴离子与维多利亚蓝4R(VB4R)离子缔合反应体系的共振发光(RL)、二级散射(DS)和反二级散射(ADS)光谱,考察了它们的光谱特征、影响因素和适宜的反应条件。研究了RL、ADS和DS强度与汞(Ⅱ)浓度之间的定量关系;提出了用RL、ADS光谱测定痕量汞的方法。对汞(Ⅱ)的检测限分别为1.33ng/mL和1.83ng/mL,可用于水中μg/L级汞的测定,并对有关机理进行了初步的探讨。     

日落黄—阳离子双子表面活性剂体系的光谱研究及应用

考察了日落黄与双子表面活性剂(16-3-16)体系的共振光散射光谱、二级散射光谱以及吸收光谱,研究了两者之间的相互作用。在不同浓度的16-3-16—日落黄水溶液中,散射光谱和吸收光谱均有所变化,表明日落黄与16-3-16之间发生较强的相互作用。此外,考察了pH、结合的稳定性、温度以及日落黄加入量等因素对散射光谱的影响;由吸收光谱数据计算得到两组分的吉布斯自由能(ΔG)以及结合常数(K_B)。另外,由于日落黄—16-3-16的共振光散射强度和二级散射强度分别与16-3-16的浓度成线性关系,建立了测定16-3-16含量的方法。     

铜(Ⅱ)-黄原酸配合物微粒体系的光谱研究及其在废水分析中的应用

采用分光光度法和共振散射光谱法研究了Cu(Ⅱ)-黄原酸配合物微粒体系。该配合物微粒体系在410nm处有一吸收峰,其吸光度与黄原酸浓度在1.0～40×10-5mol/L范围成良好线性关系,检出限(3σ)为0.5×10-5mol/L。据此建立了一个测定废水中黄原酸含量的分光光度法.该法灵敏、简便、快速、准确、重复性好,平均回收率为98%～100%,相对标准偏差RSD为0.9%～1.9%.共振散射光谱研究结果表明,该体系存在Cu(Ⅱ)-黄原酸配合物微粒,该微粒在360nm处存在共振散射效应.     

阳离子表面活性剂-曙红Y体系的二级散射光谱及其在分析化学上的应用

本文研究了阳离子表面活性剂（C－sf）与曙红Y离子缔合物的二级散射和“反二级散射”光谱．考察了它们的光谱特征,影响因素和适宜条件,提出用二级散射光谱法测定痕量c－sf的新的高灵敏度分析方法。     

小檗碱-Ⅰ3^-缔合微粒体系的光度分析应用

在稀HCl介质中,I-3在340 nm处有一吸收峰;当小檗碱(BB)与I-3共存时体系呈橙黄色,在580 nm处产生一共振散射峰.以试剂作参比,该缔合微粒体系在530 nm产生一吸收峰,BB浓度在0～7.0×10-5mol/L范围内与A530 nm呈线性,据此建立了一种测定小檗碱含量的分光光度新方法,并用于针剂样品中小檗碱测定,结果满意.同步散射光谱研究表明,BB+与I-3可通过静电引力作用形成疏水性的(I3-BB)缔合物分子,并进一步聚集形成稳定的(I3-BB)n缔合纳米微粒.由于该缔合纳米微粒在580 nm处产生共振散射效应,故体系呈橙黄色.     

硒(Ⅳ)-碘化物-结晶紫体系的共振发光和二级散射光谱

硒（Ⅳ）－碘化物－结晶紫体系的共振发光和二级散射光谱刘绍璞,刘忠芳（西南师范大学环境化学研究所,重庆,６３０７１５）关键词共振发光,二级散射,反二级散射,硒（Ⅳ）－碘化物－结晶紫体系,硒的测定长期以来,溶液体系的共振发光和二级散射现象常常被人们忽略。...     

硫酸皮肤素的共振瑞利散射法测定

研究了硫酸皮肤素对十六烷基三甲基溴化铵(CTMAB)发生缔合反应的条件、共振瑞利散射特征.结果表明,在pH 5.8的BR缓冲溶液中,硫酸皮肤素能与CTMAB形成离子缔合物,使共振瑞利散射RRS急剧增强并产生新的RRS光谱.硫酸皮肤素浓度在0.04～4.0μg/mL之间与散射强度呈线性关系,方法检出限(3σ)为13 ng/mL,并以CTMAB体系为例研究了共存物质的影响,表明方法选择性好.     

Non-trivial solution chemistry between amido-pyridylcalix[4]arenes and some metal salts

Mercury ion complexation reactions were carried out between 3 and various mercury(II) salts. (1)H NMR studies showed that the role of solvent, the anion chosen and the initial reaction conditions were critical and that the formation of a "simple" mercury(II) complex was non-trivial. The mercury(II) ion can cause either (i) the formation of an ion-pair system, which have a characteristic doubling of all signals in the (1)H NMR spectrum, (ii) a cleavage reaction to occur resulting in the reformation of the calix[4]arene diester compound 2, but only when the reaction is heated and (iii) "simple" mercury binding to the pyridine rings when the binding studies are carried out using NMR titration techniques. The electrochemistry results, on the same systems, show that the initial reaction involves the removal of the phenoxide protons followed by the resulting catalysis of the mercury species. This proton removal is not observed in the NMR spectra of any of the mercury reactions. It was also found that 3 could bind silver and zinc salts and was not selective for mercury(II) as was previously described.     

Kinetics and mechanism of mercury(II)-catalysed replacement of cyanide in hexacyanoferrate(II) by p-nitrosodiphenylamine

The mercury(II)-catalysed replacement of cyanide in hexacyanoferrate(II) by p-nitrosodiphenylamine (p-NDA) in aqueous solution has been investigated spectrophotometrically by measuring the change in absorbance of the green complex ion, [Fe(CN)(5).p-NDA](3-), at 640 nm. Activation parameters of the catalysed and uncatalysed reactions have been calculated. The effects of the dielectric constant and water content of the medium on reaction rates are used to explain the formation of a polar activated complex and suggest an I(d) mechanism for the catalysed reaction. The varying catalytic activity of Hg(II) as a function of concentration has been discussed.     

Resonance Rayleigh scattering method for the determination of trace amounts of cadmium with iodide-basic triphenylmethane dye systems

In dilute phosphoric acid solution, cadmium (II) reacts with a large excess of I- to form [CdI4]2- which reacts further with basic triphenylmethane dyes such as crystal violet (CV), ethyl violet (EV), methyl violet (MV), brilliant green (BG) or malachite green (MG) to form an ion-association complex. This results in a significant enhancement of resonance Rayleigh scattering (RRS) intensity and the appearance of new RRS spectra. The characteristics of RRS spectra of the ion-association complexes, the influencing factors and the optimum conditions of these reactions have been investigated. The intensity of RRS is directly proportional to the concentration of cadmium from 0 to 60 ng mL(-1) for EV and MV systems, 0 to 80 ng mL(-1) for CV system, and 0 to 100 ng mL(-1) for BG and MG systems. The methods exhibit high sensitivities and the detection limits for cadmium are between 0.35 and 2.00 ng mL(-1) depending on the different reaction systems. The new RRS method was applied to the direct determination of traces of cadmium in pure zinc and synthetic water samples.     

Novel mercury(II) complexes of porphyrins

Treatment of octa-alkylporphyrins (e.g. 1–3) with mercury(II) acetate in methylene chloride and tetrahydrofuran affords novel complexes (4) containing two porphyrin rings layered between three Hg atoms. A new type of stereoisomerism in regularly substituted porphyrins (e.g. 1a, 2a) is identified; it is observed by NMR spectroscopy and occurs because two forms of the complex (4) are possible, depending upon which faces of the porphyrin molecule are turned in towards the central Hg atom. The NMR spectra also indicate that in concentrated solution the double sandwich complexes (4) are stable towards disproportionation and recombination. On the basis of the inherent geometrical arrangements in the complex (4), an efficient NMR method for unambiguous identification of the four primary type isomers of the aetio- and copro-porphyrin series is described.

In very dilute solution, or in mixtures containing nucleophilic solvents such as pyridine, methanol, dioxan, or tetrahydrofuran (in the absence of excess mercury(II) acetate), the double sandwich complexes (4) are destroyed to afford normal 1:1 metalloporphyrins.     

Synthesis and Crystal Structure of a Novel 1D Mercury（II） Iodide Coordination Polymer Containing 40-Membered Macrocycle

A mercury coordination polymer [Hg3(TizT)2I6]n (Mr = 1921.72, TizT = 2,4,6- tri(imidazole-1-yl)-1,3,5-triazine) containing a 40-membered macrocycle which was constructed by four TizT ligands and four mercury(II) iodide molecules had been synthesized by the reaction of HgI2 with TizT. The complex was characterized by elemental analysis, FT-IR, 1H NMR spectra and X-ray crystallography. The crystal of the complex belongs to the monoclinic system and C2/c space group with a = 35.840(5), b = 8.169(5), c = 14.980(5) , β = 104.466(5)°, Z = 4, V = 4247(3) 3, Dc = 3.006 g·cm-3, μ = 15.223 mm-1, F(000) = 3384, Rint = 0.0504, wR = 0.0833 and constructs a chair-like conformation of cyclohexane one by one, which forms a 1-D polymer through the fashion of fused ring aromatic hydrocarbon. The hydrogen bonds and π-π interactions shape the 2-D network structure. The two compounds excited weak fluorescence.     

Relation between intramolecular NH...S hydrogen bonds and coordination number in mercury(II) complexes with carbamoylbenzenethiol derivatives

A novel series of bis(carbamoylthiophenolato)mercury(II) complexes, [Hg(S-RNHCOC6H4)2] (1, R = 2-t-Bu; 2, R = 2-CH3; 3, R = 2-C6H5CH2; 4, R = 4-t-Bu), and a tetrakis(carbamoylthiophenolato)mercury(II) complex, (NEt4)2[Hg-(S-2-CH3NHCOC6H4)4] (5), were synthesized and characterized by 1H NMR, IR, 199Hg NMR, and crystallographic analyses. The bis(carbamoylthiophenolato)mercury complexes 1-3 do not have intramolecular NH...S hydrogen bonds between the amide NH group and the sulfur atom coordinated to mercury, whereas the tetrakis(thiophenolato)mercury complex 5 does have an intramolecular NH...S hydrogen bond. A relatively weak NH...S hydrogen bond in 5 can be seen in the 1H NMR spectra and the IR spectra in chloroform and in the solid state. The 199Hg NMR spectra in bis(carbamoylthiophenolato)mercury complexes 1-4 show a downfield shift, with an increase in the flow of electrons to mercury(II) from the oxygen atom due to the intramolecular Hg...O bonding interaction. Conversely, the 199Hg NMR spectra in 5 show a high-field shift with a decrease in the flow of electrons to mercury(II) from the sulfur atom due to the intramolecular NH...S hydrogen bond.