Synthesis, characterization and crystal structure of cationic bis(pyridinylimine)cobalt(II) complexes

• This work represents a new way to access cationic cobalt(II) complexes.
• The complexes were prepared by abstracting a halide from neutral precursors.
• Distorted trigonal bipyramidal arrangement around the cobalt center.
• Novel cationic cobalt precursors can be useful as catalysts.

Ligands 2,6-dimethyl-N-(pyridin-2-ylmethylene)aniline C14H14N2 (L1), 2,6-dimethyl-N-(1-(pyridin-2-yl)ethylidene)aniline C15H16N2 (L2) and 2,6-diisopropyl-N-(1-(pyridin-2-yl)ethylidene)aniline C19H24N2 (L3) were obtained by condensation reactions. The reactions of CoCl2·6H2O with the corresponding ligands L1–L3 in the presence of the new salt methoxytris(dimethylamino)phosphonium hexafluorophosphate [CH3OP(NMe2)3]+PF6− afford in good yields, the complexes bis[2,6-dimethyl-N-(pyridin-2-ylmethylene)aniline]chloro cobalt(II) hexafluorophosphate C28H28ClCoF6N4P (C1), bis[2,6-dimethyl-N-(1-(pyridin-2-yl)ethylidene)aniline]chlorocobalt(II) hexafluorophosphate C30H32ClCoF6N4P (C2) and bis-[2,6-diisopropyl-N-(1-(pyridin-2-yl)ethylidene)aniline]chlorocobalt(II) hexafluorophosphate C38H48ClCoF6N4P (C3). All new complexes C1–C3 have been characterized by CHN analyses, 1H, 13C, 31P NMR and IR spectroscopy. Solid state and electronic structures of complex C1 have been determined.

Ligands (pyridin-2-ylmethylene)anilines (L1) and (1-(pyridin-2-yl)ethylidene)anilines (L2–L3) were obtained by condensation reactions. The reactions of CoCl2·6H2O with ligands L1–L3 in the presence of methoxytris(dimethylamino)phosphonium hexafluorophosphate [CH3OP(NMe2)3]+PF6− afford, in good yields, the [bis(iminopyridine)CoCl]+[PF6]− complexes.Figure optionsDownload as PowerPoint slide