4,5-二溴苯基荧光酮与金属离子的显色反应及混合表面活性剂的作用机理

本文研究了在表面活性剂(Sf)存在下,4,5-二溴苯基荧光酮(简称 diBr-PF)与12个金属离子(Me)的显色反应.结果表明,diBr-PF 是 Me 的一个高灵敏显色剂.用 Hückel 分子轨道法(HMO)计算了 diBr-PF 的(?)电子密度,判断了 diBr-PF 各级 H~+的离解顺序及其和 Me 的配合位置;测定了在不同 Sf 存在下,diBr-PF 的各级酸离解常数(pK_a)及绘制了它的分布曲线;并研究了阳离子型(C-Sf)-非离子型(n-Sf)混合 Sf 对 Me—diBr-PF 显色反应体系的作用机理.     

2, 3, 7-三羟基-9-间羟基苯基荧光酮的合成及其 分析性能的研究

研究合成了新试剂2,3,7-三羟基-9-间羟基苯基荧光酮(简称m-HPF)。测定了试剂各级酸离解常数。研究了试剂的化学发光性能和试剂与金属离子的显色行为。结果表明,只有Co^2^+离子对m-HPF-H~2O~2体系有较强的催化发光作用;在表面活性剂存在下,试剂与许多离子都呈灵敏的显色反应。用Huckel分子轨道法(HMO)计算了中性分子及各离子构式的π电子分布,对离解常数进行了归属。     

三氮烯试剂的结构与性能关系的研究

为建立三氮烯试剂结构与性能的关系, 我们研究了在非离子型表面活性剂TritonX-100存在下, 上述试剂亚氨基氢的酸性离解常数及镉(II)与上述试剂的显色反应。研究结果表明: (1)三氮烯试剂亚氨基氢的酸性离解常数遵循Hammett方程式, 其反应常数ρ=2.23; (2)试剂的亚氨基氢的酸性离解常数(pKa)与试剂和镉(II)显色反应的最佳酸度(pH最佳)之间的经验关系式为pH最佳=pKa-(1.70±0.20)。     

几种新重氮氨基试剂的合成及其分析性能

合成了 6种新的重氮氨基新试剂。研究了试剂亚氨基质子的离解常数p Ka及试剂与 Cd( )的显色反应。结果表明 ,随着试剂 1位苯环上的对、间位取代基的取代基常数 σ值的增大 ,试剂亚氨基的质子离解常数 Ka也增大 ( p Ka值减小 ) ,与 Cd2 +反应的显色酸度也越高 ;反应的最佳操作酸度 p H操作 与试剂p Ka存在如下关系 :p Ka=p H操作 - ( 1 .4± 0 .2 )     

DBC-偶氮胂在水溶液中离解作用的研究

3-(2-胂酸基苯偶氮-6-(2,6-二溴-4-氯苯偶氮)-4,5-二羟基-2,7-萘二磺酸(简称DBC-偶氮胂)可在高酸度下(0.2-1.7NHCl)与稀土元素发生灵敏显色反应,且选择性非常好,前文已报导用该试剂直接光度测定高温合金中微量铈sup>[1]。本文研究了DBC-偶氮胂在水溶液中的离解作用,用pH电位法及分光光度法测定DBC-偶氮胂及各级条件离解常数,结果表明:由于多卤素原子的引入,使试剂更易于质子化;因而离解常数比偶氮胂Ⅲ大。     

新有机试剂4-(2-苯并噻唑偶氮)焦棓酚的合成、性能和分析应用

本文以2-氨基苯并噻唑为原料,经重氮化后与焦棓酚偶联合成了4-(2-苯并噻唑偶氮)焦棓酚,用乙醇重结晶精制。并用元素分析、波谱等鉴定了结构。测定了其离解常数和质子化常数。研究了该试剂的一般性质、多配位显色反应,发现其与Mo(Ⅵ)、W(Ⅵ)、Ti(Ⅳ)等的显色反应在CTMAB和CPB等阳离子表面活性剂存在下有高的灵敏度。     

表面活性剂和胶束增溶分光光度法

在金属-有机试剂显色体系中添加表面活性剂(简写作Sf),利用Sf胶束的增溶、增敏、增稳、褪色、析相等作用,以提高显色反应的灵敏度、对比度和(或)选择性,改善显色反应条件,并在水相中直接进行光度测量的光度分析方法,称为胶束增溶分光光度法,简称增溶光度法。1958年Chavanne和Geronimi首先使用聚乙烯醇吡咯烷酮(一种非离子表面活性剂)作增溶剂,以镉试剂测定镉和汞。1962年后,Malat报导,在动物胶存在下用邻苯二酚紫测定锡、铟、钛。但是这     

新试剂10—（2—羧基苯偶氮）—9—菲酚合成及与铜显色反应

本文研究新试剂10-(2-羧基苯偶氮)-9-菲酚(CAP)的合成.测定试剂的离解常数,研究在PVA存在下铜与新试剂CAP的显色反应.在确定条件下,钢与CAP试剂形成1:2的橙红色络合物,比耳定律的适宜范围Cu 0～20μg/25ml,反应有较好的选择性.可不经分离,光度法直接测定钢铁中铜.     

双波长分光光度法测定大米中的痕量镉——Cd(Ⅱ)-Cadion 2B-Tween 40体系

本文研究了Cd(Ⅱ)-Cadion 2B-Tween 40显色反应的最佳条件。测定了不同Tween 40浓度下Cadion 2B的酸离解常数和表面张力。实验证明,Tween 40促进了Cadion 2B的酸离解作用。过量试剂的消耗时Cd(Ⅱ)有强烈的响应,用ΔA_(510-605nm)测定Cd(Ⅱ),其表观摩尔吸光系数ε_(510-605nm)=2.60×10~5。Cd(Ⅱ)在0—16μg/25ml范围内符合比尔定律。利用TEA、IDA、Cit混合掩蔽剂,并采用标准加入法测定了大米中的痕量镉。     

多元络合物显色反应中的有机溶剂化效应——铁(Ⅲ)-铬天青S-溴化十六烷基三甲铵-含氧有机溶剂体系

本文研究了Fe(Ⅲ)-铬天青S(CAS)-溴化十六烷基三甲铵(CTAB)体系显色反应的有机溶剂化效应.拟定了测定痕量铁的分光光度法.探讨了溶剂化效应机理.测定了络合物组成及溶剂化数.研究了有机溶剂对CAS离解常数(K_a3,K_a4)及Fe(Ⅲ)-CAS络合物稳定常数的影响.     

Quantitative structure-property relationships for colour reagents and their colour reactions with cerium using computational neural networks

Quantitative structure-activity/property relationships (QSAR/QSPR) studies have been exploited extensively in the designs of drugs and pesticides, but few such studies have been applied to the design of colour reagents. In this work, the topological indices A(x1) - A(x3) suggested in this laboratory were applied to multivariate analysis in structure-property studies. The topological indices of 43 phosphone bisazo derivatives of chromotropic acid were calculated. The structure-property relationships between colour reagents and their colour reactions with cerium were studied using A (x1 a (x)3) indices with satisfactory results. The purpose of this work was to establish whether QSAR can be used to predict the contrasts of colour reactions and in the longer term to be a helpful tool in colour reagent design.     

Synthetic and analytical studies on colour reagents-IX The reactions of phthaleinazo compounds with the alkaline earths

Some new phthaleinazo compounds-o,o'-dihydroxyazo compounds-have been prepared by coupling chromotropic acid, R-acid, and 2-hydroxy-3-naphthoic acid with bis-diazotized diaminophthaleins. These compounds have been found to be very sensitive colour reagents for alkaline earths in alkaline media, and in particular, bis(chromotropeazo)phenolphthalein is the most sensitive yet found.     

Improved selectivity of chemical colour reactions by simple gas chromatographic separation

Gas chromatography is applied to improve the selectivity of sensitive organic colour tests without the use of complicated apparatus.     

A study on the colour reactions of germanium with 9-substituted-2,3,7-trihydroxyfluorones in the presence of cationic surfactants

In the investigation on the sensitization of micelle colour reactions of germanium ton with eight 9-substituted-2,3,7-trihydroxyfluorones (methyl-, phenyl- p-bromophenyl-, p-dimethylaminophenyl- m-nitrophenyl-, o-nitrophenyl-, salicyl- and β-hydroxynaphthyl-) in the presence of cationic surfactant CTMAB, it is found that salicyl- and o-nitrophenylfluorones can form highly sensitive ternary complexes with germanium and CTMAB bromide in a strongly acidic medium. The conditions of spectrophotometric determination of micro amounts of germanium with of o-nitrophenylfluorones and CTMAB, the composition of the related complexes and the mechanism of the sensitization of micelle have been studied in detail. This method can be applied without separation to determine rapidly the micro amounts of germanium in lead-zinc ores with satisfactory results.     

阳离子表面活性剂存在下锗与2,3,7-三羟基-9-取代萤光酮显色反应的研究

本文研究了八种2,3,7-三羟基-9-取代荧光酮在阳离子表面活性剂存在下与锗的胶束增敏显色反应.发现水杨基萤光酮及邻硝基苯基萤光酮在强酸性介质中可以和溴化十六烷基三甲基铵形成高灵敏的胶束三元配合物.较详细地研究了用邻硝基苯基萤光酮与溴化十六烷基三甲基铵分光光度法测定微量锗的实验条件.并探讨了有关配合物的组成以及胶束增敏反应的机理.此法可不经分离,直接快速测定铅锌矿中的微量锗,结果比较满意.     

新不对称偶氮羧衍生物的合成及其与钙离子的β型显色反应

我们合成了五种新的不对称偶氮羧衍生物,并研究了它们与钙离子之间的一种特殊反应-β型反应,考察了试剂分子结构与反应性能的关系。着重探讨了对羧基偶氮羧与钙离子的β型反应行为,在柠檬酸介质中,钙离子与该试剂形成组成比为1:2的灵敏的稳定配合物,最大吸收波长为718nm(Δλ=157nm),表观摩尔吸光系数ε=1.51×10^5L.mol^-^1.cm^-^1,测定条件下,1-13μgCa/25mL符合Beer定律,采用小体积显色,反应可在15分钟内进行完全,配合物可稳定4小时不变。动力学研究结果表明,对羧基偶氮羧与钙离子只发生β型反应,反应级数为2。     

Analytical method for determining colour intensities based on Cherenkov radiation colour Quenching

In the present work a study was made for determining colour intensities using as luminous non-monochromatic source the Cherenkov emission produced in the walls of a glass capillary which acts as luminous source itself inside of a coloured solution to be evaluated. The reproducibility of this method has been compared with the spectrophotometric assay; the relative errors of both analytical methods have been calculated for different concentrations of congo red solution in the range of minimal error, according to Ringbom's criterion. The sensitivity of this analytical method has been studied for the two β-emitters employed:⁹⁰Sr/⁹⁰Y and²⁰⁴Tl.     

Studies on the mechanism of the Carr-Price blue colour reaction

The reaction of retinoids (retinol, retinyl acetate and anhydroretinol) with Br?nsted acids was studied as a model system for the Carr-Price reaction. The anhydroretinylic cation was characterised by VIS and 2D NMR spectroscopy, including an estimate of the charge distribution and region of bond inversion, observed in a mixture of identified E/Z isomers. Products obtained by quenching with NaOMe-MeOH were identified by HPLC and MS. The classical Carr-Price reaction between retinol (vitamin A) and the Lewis acid SbCl(3) in saturated chloroform solution was reinvestigated by VIS, NMR, EPR, dynamic light scattering and chemical quenching. Whereas product instability and failure to provide informative NMR spectra indicated a radical cation, EPR results excluded free-radical species. Dynamic light scattering experiments, in comparison with model systems, revealed strong aggregation for the Carr-Price complex, rationalizing the low stability, NMR problems and dimerisation observed by chemical quenching. The VIS data support structural similarity of the blue Carr-Price product with the delocalized anhydroretinylic cation, and a detailed structure of the antimony complex is evaluated.