Influence of carboxylate counter anions on the cationic framework of 1,10-phenanthroline cobalt(III) complexes: Syntheses, characterization and single crystal structure determination of [Co(phen)2CO3]X.nH2O complexes

Abstract

Cobalt(III) complexes containing carboxylate anions, [Co(phen)2CO3]X·nH2O, where X=trifluoroacetate (tfa, n=5; 1), 4-chloro-3-nitrobenzoate (3-cnbz, n=6; 2), 4-chloro-2-nitrobenzoate (2-cnbz, n=4; 3), 2,4-dinitrobenzoate (dnbz, n=1; 4), have been synthesized by the reaction of [Co(phen)2CO3]Cl·5H2O and corresponding sodium salt of carboxylic acid in aqueous medium. These complexes were characterized by elemental analysis, solubility product, conductance measurements, thermal studies and spectroscopic studies. The crystal structures of 1–4 have been determined by single-crystal X-ray structure determination. The hydrogen bonding (C–H⋯O and O–H⋯O) and π–π stacking interactions led to the formation of pillared layer, square cavities type and zig-zag layered arrangements in 2, 3 and 4 respectively, while in complex salt 1, C–H⋯F interactions have been observed between the complex cations and anions.