Non‐Planar [ n ]Cyclo‐1,8‐carbazolylenes ( n= 3,4,6) and [3]Cyclo‐1,8‐carbazolylenyl B, P, PO, SiPh Complexes

A new family of non‐planar heterocyclic molecules consisting of carbazoles was created. A bowl‐shaped cyclodimer, a flake‐shaped cyclotrimer, a double‐decker‐ring‐shaped cyclotetramer and a cyclohexamer were synthesized by Ni 0 ‐mediated one‐shot cyclo‐oligomerization of 1,8‐dibromocarbazole, and were named [ n ]cyclo‐1,8‐carbazolylenes ( n= 3,4,6). [3]Cyclo‐1,8‐carbazolylene was found to act as a trivalent tridentate ligand for heteroatoms (B, P, Si), giving flake‐shaped complexes. The boron derivative acted as a Lewis acid, and the tetra‐coordinated complexes showed an unprecedented red‐shift of absorption and emission spectra by the coordination. The synthetic method, the distorted C 2 or C 1 symmetric shape, the trivalent tridentate coordination ability and the kinds of introduced heteroatoms of [3]cyclo‐1,8‐carbazolylenes, the electronic structure, the photophysical property, and the Lewis acidity were distinct from those of related subporphyrins/subphthalocyanines.