Dually Switchable Heterotetracenes: Addressing the Photophysical Properties and Self-Organization of the P-S System
Dually Switchable Heterotetracenes: Addressing the Photophysical Properties and Self-Organization of the P-S System
复制标题
DOI：
10.1021/ja108081b
复制
发表时间：
2011-02-09
影响因子：
15
通讯作者：
Baumgartner, Thomas
中科院分区：
文献类型：
--
作者：
Ren, Yi;Baumgartner, Thomas
合成了新的梯形、磷和硫基杂四烯，利用硫和磷之间的不同反应活性，实现了材料性质的工程化。P-31核磁共振波谱。光谱和X射线结晶学研究表明，二次杂原子硫的不同电子效应不仅影响杂四茂铁核的共轭作用，而且影响磷中心的行为。UV-Vis和荧光光谱表明，支架的带隙主要由硫的电子性质控制，而荧光量子产率则高度依赖于磷的电子性质。循环伏安法表明，体系的氧化还原性质可以通过选择性修饰相应的杂原子(硫的氧化和/或三价磷的官能化)来改变。重要的是，磷中心的氧化导致杂四茂铁体系的还原特性增强，而硫中心的氧化进一步增强了核心的电子受体特性。理论计算提供了磷化学的选择性和两个杂原子(硫和磷)之间的通信的见解。当四茂铁核被侧链官能团官能化时，观察到杂四烯的宏观自组织。荧光显微镜和扫描电子显微镜证实了这一点，初步结果表明，分子中的烷基链沿着分子的长轴延伸可以诱导ID微纤维的形成。
New ladder-type, phosphorus- and sulfur-based heterotetracenes were synthesized, which allowed the engineering of the materials' properties by exploitation of the different reactivities between sulfur and phosphorus. P-31 NMR. spectroscopy and X-ray crystallographic studies revealed that the different electronic effects of the secondary heteroatom, sulfur, influence not only the conjugation in the heterotetracene core but also the behavior of the phosphorus center. UV-vis and fluorescence spectroscopy showed that the scaffold's band gap is mainly controlled by the electronic nature of sulfur, while the fluorescence quantum yield highly depends on the electronic nature of phosphorus. Cyclic voltammetry indicated that the redox properties of the system could be altered by selective modification of the respective heteroatom (oxidation of sulfur and/or functionalization of trivalent phosphorus). Importantly, oxidation of the phosphorus center results in enhanced reduction features of the heterotetracene system, and oxidation of the sulfur center further enhances the electron acceptor character of the core. Theoretical calculations provided insights on both selectivity of phosphorus chemistry and communication between the two heteroatoms (sulfur and phosphorus). Macroscopic self-organization of the heterotetracenes was observed when the tetracene core is functionalized with pendant functional groups. Preliminary results showed that extension of the molecule with an alkyl chain along the long axis of molecules induces the formation of ID microfibers, which was confirmed by fluorescence microscopy and scanning electron microscopy.