Heterometallic Pd^II–Ni^II Complexes with <i>meso</i>-Substituted Dibenzotetraaza[14]annulene: Double C–H Bond Activation and Formation of a Rectangular Tetradibenzotetraaza[14]annulene

Three isomeric 2­[PdII–NiII] metal complexes, derived from indoleninyl meso-substituted dibenzotetraaza[14]­annulene, were synthesized. The resulting dimers feature Ni···Ni or, alternatively, Ni···π interactions in staggered or slipped cofacial structures. A remarkable insertion of palladium into two different C–H bonds yielded a 4­[PdII–NiII] rectangular complex with dimensions of 8.73 × 10.38 Å.