Role of non-covalent interactions in binding of non-coordinating anions: Syntheses, characterization and single crystal structure determination of cobalt(III) complexes with 2,2′-biimidazole and 1,10-phenanthroline ligands

► New mixed ligand Co(III) complex, [Co(phen)2(Hbiim)]Cl2·10H2O has been synthesized. ► Above complex is utilized in syntheses of three new complexes [Co(phen)2(Hbiim)](X)2 (where X=I-/ClO4-/IO4-). ► Non-covalent interactions C-H⋯O, N-H⋯N, C-H⋯π, π-π stacking are playing crucial role in lattice stabilization. ► The anionic moieties are arranged like pillars in between sheets of complex cations through second sphere interactions.