Self-assembly of a Co4III face-shared partial double cubane supported by alkoxo terminal and bridging ligands

The double μ3-OMe supported tetrameric Co4 complex [Co4(μ3-OMe)2(μ-bemp)2(N3)2(OH2)2](ClO4)2 · 4H2O {1 · (ClO4)2 · 4H2O} was isolated from the reaction of Co(ClO4)2 · 6H2O with H3bemp (where H3bemp = 2,6-bis-[(2-hydroxy-ethylimino)-methyl]-4-methyl-phenol) and NaN3 in presence of NEt3 in aqueous methanol. The X-ray structure analysis reveals a cationic tetrameric arrangement consisting of a defective dicubane-like core with two missing vertexes. The four Co(III) ions are connected through in situ generated μ3-OMe and central phenolate plus terminal ethanolate bridges of the ligand. Terminal aqua and azido coordinations finally fulfil the octahedral geometries around the CoIII ions within this Co4 aggregate.

A novel [Co4II] cluster [Co4(N3)2(μ3-OMe)2(μ-bemp)2(OH2)2](ClO4)2 · 4H2O {1 · (ClO4)2 · 4H2O} is formed with help of solvent derived MeO− templates, in presence of N3- bridges, together with the parent fully deprotonated di-Schiff-base ligand bemp3−, featuring two fused defective cubanes. Central phenoxide and terminal alcoholate type bridges facilitate octahedral coordinations and aggregation of the Co4 cluster complex.Figure optionsDownload as PowerPoint slide