铁(Ⅲ)—邻菲罗啉溶液体系的光化学还原 Ⅱ.气相色谱法研究光化反应机理  

STUDIES ON PHOTOREDUCTION OF IRON(III)II .1,10 PHENANTHROLINE IN SOLUTION BY GAS CHROMATOGRAPHY

作　　者：颜科[1] 沙德仁[1] 谭明霞[1] 

机构地区：[1]南京玻璃纤维研究设计院,南京210012

出　　处：《无机化学学报》1990年第2期239-241,共3页Chinese Journal of Inorganic Chemistry

摘　　要：关于Fe(Ⅲ)—邻菲罗啉(phen)溶液的光化学还原现象的记载可追溯到十九世纪末。本世纪以来,许多化学家用多种不同的方法对其进行了研究,但对其反应机理至今仍无定论。我们在前文研究的基础上,用气相色谱法(GC)对溶液体系光化反应后的气相组成进行了分析,并测定吸光度A_(510)值以及反应前后pH值的变化,从而推论在溶液中发生的反应。本文提出的关于光化反应是通过在溶液中形成的DAC(电子给予体—接受体配合物)来进行的假定,有待于用其他动力学方法加以研究。By using gas chromatograph, spectrophotometer and acidimeter, we studied the photoreduction of Fe(Ⅲ)-phen (1, 10 phenanthroline) in solution, The results of the investigation reveal that, the photoreduction reaction of Fe (Ⅲ)-phen in solution is also dependent on the composition of the solution system. Under suitable pH condition (pH>2), by using sunligitomhigh-pressure fluorescent bulb as light source, the photochemical reduction produce the solution containing Fe(Ⅲ)-phen only. This meant that water appeared to be an electron donor. In the presence of citric acid and other organic ligands, CO2 produced. In this case the organic ligands were the electron donors. On using acetic acid instead of citric acid, the photochemical reduction produce O2 and CO2. In this case, both water and acetic acid were the electron donors. When pH value of the solution became less than 1.0, the photochemical reduction would not happen. After the photochemical reduction, pH value of the solution became low. We hypothesize that photoreduction mechanism of the Fe(Ⅲ)-phen solution is involving the formation of the mononuclear or polynuclear complex in Fe(Ⅲ)-phen solution -Fe(Ⅲ)x(phen)YLz(where, L = OH-, neutral molecules such as H2O etc., or organic ligands, X,Y,Z= 1,respectively), that is, the electron donor -accepter complex DAC formed as a starting material. Then the DAC would be reduced to Fe(phen)32+ by light with excess phen. The experiment indicates that different L induces different reactions in solution.

关 键 词：铁 邻菲罗啉 光化学还原 气相色谱 

分 类 号：O614.811[理学—无机化学]