Synthesis and structure of polycrystalline adducts of Co(II) azomethine complexes with redox-active 2,4,6,8-tetrakis-(tert-butyl)phenoxazin-1-one

Abstract

The six-coordinate cobalt complexes, C₅₇H_63.50N_4.50O₄Co (IIa), C₆₀H₆₉N₅O₄Co (IIb), C5₈H₆₇N₃O₈Co (IIc), C₅₆H₆₁N₅O₁₀Co (IId), C₅₆H₆₃N₃O₆Co (IIe), C₅₈H₆₆N₄O₆Co (IIf), and C₅₈H₆₃N₇O₈Co (IIg), adducts of high-spin tetrahedral Co(II) bis(salicylaldiminates) (C₂₉H_24.50N_3.50O₂Co (Ia), C₃₂H₃₀N₄O₂Co (Ib), C₃₀H₂₈N₂O₆Co (Ic), C₂₈H₂₂N₄O₈Co (Id), C₂₈H₂₄N₂O₄Co (Ie), C₃₀H₂₇N₃O₄Co (If), and C₃₀H₂₄N₆O₆Co (Ig)) and redox-active 2,4,6,8-tetrakis(tert-butyl)phenoxazin-1-one (L), were synthesized and studied for structure and magnetic properties. Complexes IIa–IIg have octahedral structure (CIF files CCDC nos. 1403920 (IIf), 1403922 (IIg)) and exist in the ground low-spin state (ls-Co^III-SQ), which arises upon intramolecular single-electron redox process in the ligand–metal system. The presence of substituents of different nature in the azomethine ligands of IIa–IIg does not induce any significant changes in their magnetic properties.