Singly, Doubly, and Triply Linked Corrole Oligomers: Synthesis, Structures, and Linking Position Dependent Properties

Direct covalent connections of porphyrinoids have been demonstrated as an effective way to expand their π-electronic networks and perturb their optical and electrochemical properties. Covalent connections are also useful for studies on the precise electronic interaction between two porphyrinoid units. However, the chemistry of covalently linked corrole oligomers lags far behind that of the porphyrin counterparts in spite of the importance of corrole as a ring-contracted porphyrinoid. The lower symmetry of corroles naturally leads to many possible corrole dimers, which have been found to display different optical and electrochemical properties depending on the linking position. In this review, we summarize the synthesis, structures, and properties of corrole oligomers such as singly linked oligomers and fused dimers as well as their metal complexes with a particular focus on their linking position dependent electronic properties.