Swavey Shawn, Kumar Sreedhar V, Erb Jeremy
Department of Chemistry, University of Dayton , 300 College Park, Dayton, Ohio 45469-2357, United States.
Inorg Chem. 2017 Sep 5;56(17):10664-10673. doi: 10.1021/acs.inorgchem.7b01630. Epub 2017 Aug 22.
A series of new Bodipy dyes incorporating the π-extended isoquino[5,6-c]pyrrole have been synthesized and characterized. The dyes display intense Bodipy (π-π*) transitions and emissions with high quantum efficiencies. Spectroscopic, electrochemical, and theoretical calculations are used to give insight into the frontier orbitals. Coordination of {Ru(bpy)Cl} subunits to the peripheral isoquinol nitrogen atoms of the Bodipy dyes leads to three new bis-Ru(II)-polypyridyl-Bodipy complexes with the Ru(II) centers in direct contact with the dipyrrin core. Spectroscopic studies of the complexes reveal the traditional metal to ligand charge transfer (MLCT) transitions associated with Ru(dπ) to bpy(π*) transitions. However, a more intense transition above 600 nm is also observed. This transition is independent of the meso-substituents of the dipyrrin and is shifted to lower energy by as much as 25 nm compared to that of the Bodipy dyes without the Ru(II) subunits. Spectroscopic, electrochemical, and spectroelectrochemical studies suggest that the Bodipy π-orbitals are destabilized by coordination of the Ru(II) moieties. All three Ru-Bodipy complexes show the ability to generate singlet oxygen when irradiated within the photodynamic therapy window (600-850 nm) as evidenced by singlet oxygen trapping experiments.
一系列包含π-扩展异喹啉并[5,6-c]吡咯的新型Bodipy染料已被合成并表征。这些染料表现出强烈的Bodipy（π-π*）跃迁和具有高量子效率的发射。通过光谱、电化学和理论计算来深入了解前沿轨道。{Ru(bpy)Cl}亚基与Bodipy染料的外围异喹啉氮原子配位，形成了三种新的双Ru(II)-多吡啶-Bodipy配合物，其中Ru(II)中心与二吡咯核心直接接触。对这些配合物的光谱研究揭示了与Ru(dπ)到bpy(π*)跃迁相关的传统金属到配体电荷转移（MLCT）跃迁。然而，还观察到在600 nm以上有更强的跃迁。该跃迁与二吡咯的中位取代基无关，并且与不含Ru(II)亚基的Bodipy染料相比，其能量降低了多达25 nm。光谱、电化学和光谱电化学研究表明，Ru(II)部分的配位使Bodipy的π轨道不稳定。单重态氧捕获实验证明，所有三种Ru-Bodipy配合物在光动力治疗窗口（600-850 nm）内照射时都具有产生单重态氧的能力。
