Building Large Structures with Curved Aromatic Surfaces by Complexing Metals with Phosphangulene

Phosphangulene (1) is a hexacyclic triarylphosphine with a distinctive conical shape and an electron-rich aromatic surface that is geometrically and electronically complementary to fullerenes such as C60 and C70. As a result, suitable derivatives of phosphangulene can cocrystallize with fullerenes or even bind them in solution. Surprisingly, previous work has largely overlooked the potential of phosphangulene to form complexes with metals, which offers a simple way to create large molecular structures with curved aromatic surfaces. To explore this approach, we have prepared and characterized a series of complexes of phosphangulene with Ag+ and Cu+. Our results show that Phang ligands are exceptional for many reasons. In particular, they can yield metal complexes with unique coordination, and the metal centers hold the concave aromatic surfaces of multiple ligands in various divergent arrays. Moreover, the rigid conical structure of phosphangulene gives the complexes an awkward shape that cannot be packed efficiently without complementary partners. As a result, metal complexes of phosphangulene are predisposed to cocrystallize with fullerenes, thereby yielding materials in which metals and fullerenes are brought together in ordered arrangements.磷杂薁（Phosphangulene，1）是一类六环三芳基膦，具备独特的锥形结构与富电子芳香表面，其几何与电子特性与C60、C70等富勒烯（fullerene）高度互补。因此，磷杂薁的合适衍生物可与富勒烯形成共晶体，甚至可在溶液中与富勒烯结合。令人意外的是，此前的研究大多忽略了磷杂薁与金属形成配合物的潜力，而这一途径可简便构建带有弯曲芳香表面的超大分子结构。为探索此研究方向，我们制备并表征了一系列磷杂薁与Ag+、Cu+的配合物。我们的研究结果显示，Phang配体（Phang ligands）具备诸多优异特性：具体而言，其可形成具有独特配位模式的金属配合物，金属中心以多种发散式排布，将多个配体的凹面芳香表面锚定。此外，磷杂薁的刚性锥形结构赋予配合物一种难以高效堆积的特殊构型，若无互补性客体则无法实现有效堆砌。因此，磷杂薁的金属配合物易于与富勒烯共结晶，最终得到金属与富勒烯按有序排布的材料。