Tafesse Fikru, Eguzozie Kennedy
Department of Chemistry, University of South Africa, P.O. Box 392, UNISA Pretoria, Republic of South Africa.
Ecotoxicol Environ Saf. 2009 Mar;72(3):954-9. doi: 10.1016/j.ecoenv.2008.01.010. Epub 2008 Mar 4.
The hydrolysis of 4-nitrophenylphosphate (NPP) in the presence of copper bipyridyl Cu(bpy)(H(2)O)(2) in oil in water microemulsion media was investigated. The reaction was monitored by measuring the absorbance of the nitrophenolate ion produced in the reaction aliquots with time. The order of effectiveness of the microemulsion system towards the hydrolysis of NPP in the presence of the copper dipyridyl complex was found to be cationic>anionic>aqueous at neutral pH. The result of the present investigation exhibits catalytic turnovers for metal to NPP ratio of 1:20. Catalysis in the microemulsion mediated reaction solutions was evident even in low concentrations of the metal ions in 1:2000 metal to NPP ratio. An explanation for the enhanced catalytic activity of the Cu(bpy)(H(2)O)(2) complex for the hydrolysis of NPP is afforded. The application of the above systems for possible environmental decontamination of aryl organophosphates is anticipated.
研究了在水包油微乳液介质中，联吡啶铜[Cu(bpy)(H₂O)₂]²⁺存在下4-硝基苯磷酸酯（NPP）的水解反应。通过测量反应等分试样中随时间产生的硝基酚盐离子的吸光度来监测反应。发现在中性pH下，微乳液体系对在联吡啶铜配合物存在下NPP水解的有效性顺序为阳离子型＞阴离子型＞水相。本研究结果表明金属与NPP比例为1:20时存在催化周转。即使在金属离子与NPP比例为1:2000的低浓度下，微乳液介导的反应溶液中的催化作用也很明显。对[Cu(bpy)(H₂O)₂]²⁺配合物对NPP水解增强的催化活性给出了解释。预期上述体系可用于芳基有机磷酸酯的可能环境净化。
