Synthesis and characterization of cobalt complexes with pentafluorophenylhydrazine: Nucleophilic attack of phenolic oxygen to pentafluorophenyl ring during condensation of two Schiff base ligands

A new dinuclear complex of Co(III), [Co(L1′)(μ-N3)(N3)]2 (1) and a mononuclear complex of Co(II) [Co(L2)2(N3)2] (2) were synthesized and characterized by elemental analyses, spectroscopic methods and X-ray diffraction analyses [L2 is (E)-2-(1-(2-(perfluorophenyl)hydrazono)ethyl)pyridine and HL1′ is a ligand which formed by condensation of two molecules of the other Schiff base ligand HL1 = (E)-2-((2-(perfluorophenyl)hydrazono)methyl)phenol]. In complex 1 the final ligand HL1′ was formed via nucleophilic attack of the NH group in one hydrazone to the azomethine moiety in another hydrazone and the subsequent SNAr reaction of the phenolic oxygen to pentafluorophenyl nucleus giving rise to PhOPh structure.