Synergistic cation-to-anion and anion-to-cation interactions in the binding of oxoanions: Syntheses, characterizations, and single-crystal structures of [Co(phen)2CO3]ClO3, [Co(phen)2CO3]BrO3·3.5H2O and [Co(phen)2CO3]IO4
Keywords: Anion receptor; Cobalt(III); Oxo-anions; X-ray crystallography;