Ayres G H, Arno J A
Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, U.S.A.
Talanta. 1971 Apr;18(4):411-27. doi: 10.1016/0039-9140(71)80060-7.
Ruthenium(III) chloride and 3,4-diaminobenzoic acid, in aqueous solution at pH 4.0-4.5, react slowly at room temperature, but more rapidly when the mixture is heated, giving solutions that go through colour transitions from amber to purple-red; maximum absorbance of fully developed solutions occurs at 550 nm. The effects of heating temperature and time, pH, reagent concentration, and other variables have been studied. The system conforms to Beer's law; optimum concentration range, for measurement in 10-mm cells, is about 0.5-2 ppm of ruthenium. Interference from foreign ions, especially other platinum elements, is avoided by a distillation separation of ruthenium. The spectrophotometric mole-ratio and continuous-variation methods indicated the presence of complexes of 1:2 and 1:3 ruthenium-to-reagent stoichiometry. Elemental analysis of solid products isolated from solution confirmed the 1:2 reaction ratio. Several other o-diamines gave similar coloured solutions and reaction stoichiometry.
氯化钌(III)和3,4 -二氨基苯甲酸在pH值为4.0 - 4.5的水溶液中，室温下反应缓慢，但混合物加热时反应加快，得到的溶液会经历从琥珀色到紫红色的颜色转变；完全显色的溶液在550 nm处有最大吸光度。研究了加热温度和时间、pH值、试剂浓度及其他变量的影响。该体系符合比尔定律；在10毫米比色皿中进行测量时，钌的最佳浓度范围约为0.5 - 2 ppm。通过钌的蒸馏分离可避免外来离子，尤其是其他铂族元素的干扰。分光光度法的摩尔比和连续变化法表明存在钌与试剂化学计量比为1:2和1:3的配合物。从溶液中分离出的固体产物的元素分析证实了反应比为1:2。其他几种邻二胺也给出了类似颜色的溶液和反应化学计量比。
