Phosphorescent and semiconductive fiber-like micelles formed by platinum(II) complexes and block copolymers
Phosphorescent and semiconductive fiber-like micelles formed by platinum(II) complexes and block copolymers
复制标题
由铂(II)络合物和嵌段共聚物形成的磷光和半导电纤维状胶束
DOI：
10.1039/c7tc04686c
复制
发表时间：
2017
影响因子：
6.4
通讯作者：
Bu Weifeng
中科院分区：
文献类型：
--
作者：
Hu Linlin;Qu Fang;Wang Yongyue;Shen Junfang;He Qun;Zhang Bin;Bu Weifeng
阳离子铂(II)络合物与带负电荷的嵌段共聚物在水中的静电自组装导致了纤维状胶束的形成，其中以铂(II)为基础的离子核被聚环氧乙烷电晕包围。各种微观观察、小角X射线散射和广角X射线散射都很好地记录了结构细节。在纤维状胶束中，意外地出现了超强分凝区，其中离子核的半宽对应于完全拉伸的阴离子块的长度。由于存在较强的铂(II)⋯铂(II)和π-π堆积作用，发光强度和量子产率都显著增加。导电原子力显微镜测量表明，单个纳米纤维具有可识别的导电性。电化学阻抗测量进一步支持了这种半导体行为。由Mott-Schottky绘制的1/C2-电位图得到的负斜率表明，这些纳米纤维是p型半导体。然而，在纤维状胶束中，强烈的磷光与明显的电导率同步发生。考虑到高度可用的方形平面d8过渡金属络合物更倾向于形成金属-金属和π-π堆积相互作用，本策略代表了一种探索强烈磷光和可察觉的导电纤维类材料的新方法。
The electrostatic self-assembly of cationic platinum(II) complexes with negatively charged block copolymers in water leads to the formation of fiber-like micelles with a platinum(II)-based ionic core surrounded by a poly(ethylene oxide) corona. The structural details are well documented by various microscopic observations, small-angle X-ray scattering, and wide-angle X-ray scattering. In the fiber-like micelles, the superstrong segregation regime appears unexpectedly, where the half widths of the ionic cores correspond to the lengths of fully stretched anionic blocks. Both the phosphorescent intensities and quantum yields increase remarkably, due to the presence of strong Pt(II)⋯Pt(II) and π–π stacking interactions. Conductive atomic force microscopy measurements reveal that the individual nanofibers possess recognizable conductivity. The semiconductive behaviors are further supported by electrochemical impedance measurements. The negative slopes obtained from Mott–Schottky plots of 1/C2versus potential suggest that these nanofibers are p-type semiconductors. However, in the fiber-like micelles, the intense phosphorescence occurs synchronously with the appreciable conductivity. Considering highly available square-planar d8 transition metal complexes that prefer to form metal–metal and π–π stacking interactions, the present strategy represents a novel approach for exploring intensely phosphorescent and appreciably conductive fiber-like materials.