21‐Carba‐23‐selenaporphyrinoid Dyads—An Azepine Unit as a Merging Motif.

The oxidation of 10,15‐diaryl‐21‐carba‐23‐selenaporphyrinoids resulted in the creation of dyads. The dimerization process follows a [5+2] cycloaddition path with the formation of an azepine unit. The arrays display two direct bonds between the peripheral carbocyclic carbon atoms of one carbaselenaporphyrinic subunit and the central carbon and nitrogen atoms of the second subunit. This results in a unique canted arrangement of two carbaporphyrinoid planes resembling an open seashell‐like motif. [ABSTRACT FROM AUTHOR]