摘要
本文初步研究了合成的植物生长素α-萘乙酸在NH_4Ac-K_2SO_4(pH=7)底液中与Eu(Ⅲ)共存时出现的催化前波,其反应机理为Eu(Ⅲ)在吸附了萘乙酸的汞电极上,形成电活性络合物,其它植物生长素如吲哚-3-乙酸、吲哚-3-丙酸、吲噪-3-丁酸等,都能与Eu(Ⅲ)形成类似的极谱催化前波,而使Eu(Ⅲ)的氧化还原反应变得比较可逆。
A polarographic catalytic prewave of Eu(1) with a-naphthaleneacetic acid(NAA) was obtained in a solution of 0. 2 mol/L NH4Ac-0. 05 mol/L K2SO4, pH 7. 0. The concentration of Eu(Ⅲ) from 3. 0 × 10-6 to 1. 0 ×10-4 mol/L, and that of NAA from 5. 0×10-6 to 3. 0× 10-5 mol/L are directly proportional to the peak heights. The mechanism was investigated by several methods, such as linear sweep, cyclic voltammetry, AC polarography, differential pulse polarography,etc.Wesuggest that NAA be adsorbed on the surface of mercury electrode, and it complexes with Eu(Ⅲ) diffusing to the surface. The formation of complex on the mercury surface facilitates the reduction of Eu(Ⅲ). In the similar way, we have also obtained the catalytic prewaves of Eu(Ⅲ) with other auxins, such as indole-3-acetic acid (LAA), indole-3-propanoic acid(IPA) and indole-3-butanoic acid (IBA). The formation of polarographic prewaves could be useful to get some information about the additive effect of rare earths with auxins for promoting the growth of plant roots.
出处
《高等学校化学学报》
SCIE
EI
CAS
CSCD
北大核心
1991年第8期1032-1035,共4页
Chemical Journal of Chinese Universities
基金
国家自然科学基金
关键词
极谱催化前波
稀土
Α-萘乙酸
铕
Eu(Ⅲ)-α-naphthaleneacetic acid, Adsorption on mercury electrode, Catalytic prewave
