Synthese von Nickelkomplexen mit porphinoidem Ligandsystem

Synthesis of nickel complexes with a porphine‐type ligand system In the presence of nickel(II) salts the bicyclic vinylogous amidine 1 is dimerized to the diamagnetic (1‐amino‐10,20‐diaza‐octahydroporphinato)nickel(II) complex 3 . The condensation proceeds through a paramagnetic octahedral nickel(II) complex 2 . Starting from 3 , the (hexadecamethyl‐10,20‐diaza‐hexahydroporphin)nickel bis (tetrafluoroborate) 7 (a (hexaaza [16]annulene)nickel(II) complex) was prepared in two steps. This highly electrophilic compound adds methoxide ions in consecutive and reversible steps to form first the (1‐methoxy‐10,20‐diaza‐octahydroporphinato)nickel tetrafluoroborate 8 and then the [ cis ‐1, 11‐dimethoxy‐decahydroporphinato (2‐)]nickel 6. 6, 7 and 8 were fully characterized and interconverted by addition and elimination reactions.