The Role of Electronic Couplings in Linear Porphyrin Arrays Probed by Single-Molecule Fluorescence Spectroscopy
The Role of Electronic Couplings in Linear Porphyrin Arrays Probed by Single-Molecule Fluorescence Spectroscopy
复制标题
单分子荧光光谱探测线性卟啉阵列中电子耦合的作用
DOI：
10.1002/chem.201100236
复制
发表时间：
2011
期刊：
影响因子：
--
通讯作者：
D.
中科院分区：
文献类型：
--
作者：
Yang;J.;Lee;J-E.;Lee;C.Y.;Aratani;N.;Osuka;A.;Hupp;J.T.;Kim;D.
采用单分子荧光检测技术研究了两类线性卟啉阵列的单分子物理性质。具有广泛π共轭的丁二炔连接阵列（ZNB）表现为光稳定的单量子系统。这一证明是由荧光强度轨迹（FIT）中的长期初始发射状态和随后的离散一步光漂白提出的。与单量子系统的行为一样，ZNB在符合测量中显示出反聚束数据。另一方面，在具有强偶极耦合的直接连接阵列（ZN）中，每个卟啉部分在光漂白动力学中保持各自的特征。FIT中的逐步光漂白解释了这种解释。大部分的FIT的ZN不携带瞬时停止的荧光发射，这已经被解释为强烈结合的电子-空穴对的弗伦克尔激子，抑制分子和周围的聚合物之间的电荷转移。这些结果揭示了多卟啉阵列中卟啉部分之间发色团间相互作用对其单分子水平荧光动力学的影响。
Single‐molecule photophysical properties of two families of linear porphyrin arrays have been investigated by single‐molecule fluorescence detection techniques. Butadiyne‐linked arrays (ZNB) with extensive π‐conjugation perform as photostable one‐quantum systems. This demonstration has been suggested by the long‐lasting initial emissive state and subsequent discrete one‐step photobleaching in the fluorescence intensity trajectories (FITs). As in the behavior of a one‐quantum system,ZNBshows anti‐bunching data in the coincidence measurements. On the other hand, in directly‐linked arrays (ZN) with strong dipole coupling, each porphyrin moiety keeps individual character in photobleaching dynamics. The stepwise photobleachings in the FITs account for this explanation. Most of the FITs ofZNdo not carry momentary cessation of fluorescence emission, which has been explained by the strongly bound electron‐hole pair of Frenkel exciton that suppresses charge transfer between the molecule and surrounding polymers. These results give insight into the influences of interchromophorinc interactions between porphyrin moieties in the multiporphyrin arrays on their fluorescence dynamics at the single‐molecule level.