Three new examples of covalently linked bis(3-pyrrolyl BODIPY)s were prepared as key precursors for the synthesis of rare hexapyrrolic ligands by treating readily available 3-pyrrolyl BODIPY with different ketones under acid-catalyzed conditions. The new bis(3-pyrrolyl BODIPY) complexes were thoroughly characterized using HR-MS, NMR spectroscopy, absorption, fluorescence, electrochemistry, and theoretical methods. The bis(3-pyrrolyl BODIPY) complexes were treated with AlCl₃ in CH₃OH at reflux for 2 h to demask BF₂ units to afford novel hexapyrrolic ligands. The hexapyrrolic ligands without isolating were treated with Zn(CH₃COO)₂ in CH₃CN at room temperature for 2 h followed by repeated recrystallization to afford crystalline bis-Zn(II) complexes. The X-ray crystallographic structure obtained for one of the bis-Zn(II) complexes revealed that it was a double-stranded bimetallic helicate containing two non-superimposable M and P enantiomers in equal amounts, which were nonseparable. Each Zn(II) ion in the bis-Zn helicate complexes was coordinated to four nitrogen atoms of two dipyrrin units from two hexapyrrolic ligands in a distorted tetrahedral geometry. The distance between two Zn(II) ions (Zn1–Zn2) in bis-Zn(II) helicate was 8.211 Å, which was longer than the distance between two Cu(II) ions (Cu1–Cu2) in our previously reported bis-Cu(II) helicate complex (7.330 Å). NMR studies indicated that the bis-Zn(II) complexes were highly symmetric. The bis-Zn(II) helicates showed broad absorption bands in the region of 400–700 nm and were nonfluorescent. DFT/TD-DFT studies were in agreement with the experimental observations.

中文翻译：

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六吡咯配体螺旋双Zn(II)配合物的合成、结构和性质

通过在酸催化条件下用不同的酮处理容易获得的 3-吡咯基 BODIPY，制备了共价连接的双（3-吡咯基 BODIPY）的三个新实例，作为合成稀有六吡咯配体的关键前体。使用 HR-MS、NMR 光谱、吸收、荧光、电化学和理论方法对新型双(3-吡咯基 BODIPY) 配合物进行了彻底表征。将双(3-吡咯基BODIPY)络合物用AlCl ₃在CH ₃ OH中回流处理2小时以脱去BF ₂单元的掩蔽，得到新型六吡咯配体。将未分离的六吡咯配体在CH ₃ CN中于室温下用Zn(CH ₃ COO) ₂处理2小时，然后重复重结晶以得到结晶双-Zn( II )络合物。其中一种双-Zn( II )配合物获得的X射线晶体结构表明，它是双链双金属螺旋，含有两种等量的不可重叠的M和P对映体，它们是不可分离的。双 Zn 螺旋络合物中的每个 Zn( II ) 离子与来自扭曲四面体几何形状的两个六吡咯配体的两个二吡啉单元的四个氮原子配位。双 Zn( II ) 螺旋结构中两个 Zn( II ) 离子 (Zn1–Zn2)之间的距离为 8.211 Å，比我们之前报道的双-Zn( II ) 螺旋结构中两个 Cu( II ) 离子 (Cu1–Cu2)之间的距离更长。Cu( II ) 螺旋络合物 (7.330 Å)。 NMR 研究表明双-Zn( II ) 配合物是高度对称的。双 Zn( II ) 螺旋在 400–700 nm 范围内显示出宽吸收带，并且无荧光。 DFT/TD-DFT 研究与实验观察结果一致。