Pentacene's extraordinary photophysical and electronic properties are highly dependent on intermolecular through-space interactions. Macrocyclic arrangements of chromophores have been shown to provide a high level of control over these interactions, but few examples exist for pentacene due to inherent synthetic challenges. In this work, zirconocene-mediated alkyne coupling was used as a dynamic covalent C-C bond forming reaction to synthesize two geometrically distinct, pentacene-containing macrocycles on a gram scale and in four or fewer steps. Both macrocycles undergo singlet fission in solution with rates that differ by an order of magnitude, while the rate of triplet recombination is approximately the same. This independent modulation of singlet and triplet decay rates is highly desirable for the design of efficient singlet fission materials. The dimeric macrocycle adopts a columnar packing motif in the solid state with large void spaces between pentacene units of the crystal lattice.

中文翻译：

---

并五苯大环化合物的形状选择性合成及几何形状对单线态裂变的影响

并五苯非凡的光物理和电子特性高度依赖于分子间的空间相互作用。发色团的大环排列已被证明可以对这些相互作用提供高水平的控制，但由于固有的合成挑战，并五苯的例子很少。在这项工作中，锆茂介导的炔烃偶联被用作动态共价 CC 键形成反应，以克规模和四个或更少的步骤合成两个几何不同的含并五苯的大环。两个大环在溶液中都经历单线态裂变，其速率相差一个数量级，而三线态重组的速率大致相同。这种单线态和三线态衰变率的独立调制对于设计高效的单线态裂变材料是非常理想的。二聚大环采用固态柱状填充基序，晶格的并五苯单元之间具有大的空隙空间。