罗丹明B-PdI_4^(2-)缔合纳米粒子体系的极谱猝灭效应

Polarographic Quenching Effect of Associated (PdI_4-2RhB)_n Nanoparticle System

罗丹明B(RhB)在 1 0mmol/LH2 SO4 中于 -0 5 9V处产生 1个单扫描极谱波 ;当有PdI2 -4 存在时 ,PdI2 -4 与RhB+主要通过静电引力形成疏水性的PdI4 2RhB缔合物分子 ;PdI4 2RhB缔合分子间由于较强的范德华力和疏水作用力可形成紫红色的、尺寸约为 2 0nm的 (PdI4 2RhB) n 纳米微粒 ,在 4 70nm处产生 1个同步散射峰 ,在 5 2 0nm处产生 1个特征共振散射峰 ;而在 -0 5 9V处的极谱峰降低。一些水溶性有机溶剂如乙醇、甲醇、丙酮等的加入可使紫红色的 (PdI4 2RhB) n 纳米微粒分解为红色PdI4 2RhB分子 ,体系的同步散射峰和共振散射峰消失 ,极谱峰和同步荧光峰增强 ,颜色恢复。紫红色 (PdI4 2RhB) n

Rhodamine B(RhB) produces a single scanning polarographic wave at -0.59 V in a 10 mmol/L H_2SO_4 solution. In the presence of PdI 2- _4, RhB + combining with it produces a hydrophobic associacid molecule PdI_4-2RhB via static attraction. By means of hydrophobic force and Van der Waal's force, this associa- ted molecules form (PdI_4-2RhB)_n associated nanoparticles in violet-red color, in size of about 20 nm. The nanoparticles exhibit a synchronous scattering peak at 470 nm and a characteristic resonance scattering peak at 520 nm, and the polarographic wave at -0.59 V is quenched. When organic solvents such as alcohols and acetone is added into the nanoparticle system, the (PdI_4-2RhB)_n nanoparticles are decomposed into PdI_4-2RhB molecules, and the two mentioned scattering peaks disappear, the polarographic wave and the synchronous fluorescence peak increase, and the color of the system reduces to red. The results demonstrate that the formation of (PdI_4-2RhB)_n associated nanoparticles caures the polarographic quenching effect and resonance scattering effect.