Bending the Macrocycle: A Deep Dive into Curved Porphyrinoids

Porphyrinoids are a well-established class of molecules, with research ranging from biological applications to light-harvesting nanorings and qubits. Recently, curved variants have received increased attention. Bending them out of planarity has been shown to impact π-π communication and self-assembly properties, making them ideal model systems for advanced molecular electronic devices and supramolecular assemblies. Carpyridines, which are macrocyclic curved porphyrinoids combining carbazole and pyridine moieties, share structural similarities with polyaromatic hydrocarbons (PAHs), and can be thought of as porphyrinoid-PAH hybrids. We became interested in carpyridines for their persistent saddle-like geometry with which we can drive self-assembly. But their unusual geometry has other consequences too, some of which we discuss in this overview.