Workman S, Richter M M
Department of Chemistry, Southwest Missouri State University, Springfield, 65804, USA.
Anal Chem. 2000 Nov 15;72(22):5556-61. doi: 10.1021/ac000800s.
The electrochemistry and electrogenerated chemiluminescence (ECL) of Ru(bpy)3(2+) (bpy = 2,2'-bipyridyl) were studied in the presence of the nonionic surfactants Triton X-100, Thesit, and Nonidet P40. The anodic oxidation of Ru(bpy)3(2+) produces ECL in the presence of tri-n-propylamine in both aqueous and surfactant solutions. Increases in both ECL efficiency (> or =8-fold) and duration of the ECL signal were observed in surfactant media. A shift to lower energies of the Ru(bpy)3(2+) ECL emission by approximately 8 nm was also observed. The one-electron oxidation of Ru(bpy)3(2+) to Ru(bpy)3(3t) occurs at + 1.03 V vs Ag/AgCl in aqueous buffered (0.2 M potassium phosphate) solution as found by square wave voltammetry. This potential did not shift in surfactant systems, indicating that the redshifts in ECL emission are due to stabilization of ligand pi* orbitals in the metal-to-ligand charge-transfer excited state. These results are consistent with hydrophobic interactions between Ru(bpy)3(2+) and the nonionic surfactants.
在非离子表面活性剂吐温X-100、西曲溴铵和诺乃洗涤剂P40存在的情况下，研究了三（2,2'-联吡啶）钌（II）（bpy = 2,2'-联吡啶）的电化学和电化学发光（ECL）。在水相和表面活性剂溶液中，三（2,2'-联吡啶）钌（II）的阳极氧化在三正丙胺存在下产生ECL。在表面活性剂介质中，观察到ECL效率（≥8倍）和ECL信号持续时间均增加。还观察到三（2,2'-联吡啶）钌（II）的ECL发射峰向较低能量方向移动了约8 nm。通过方波伏安法发现，在水相缓冲（0.2 M磷酸钾）溶液中，相对于Ag/AgCl，三（2,2'-联吡啶）钌（II）单电子氧化为三（2,2'-联吡啶）钌（III）发生在+1.03 V处。该电位在表面活性剂体系中未发生变化，表明ECL发射的红移是由于金属到配体电荷转移激发态中配体π*轨道的稳定化。这些结果与三（2,2'-联吡啶）钌（II）与非离子表面活性剂之间的疏水相互作用一致。
