Structural, electrochemical characterization and SOD mimic activities of 1D chain or 3D network encouraged by unique μ2-bridging by adipate ion in mixed ligand complexes containing α-diimine as auxiliary ligand

The present ternary complexes [Cu(ada)(phen)(H2O)]·2H2O (1), [Co2(ada)2(phen)2(H2O)2] (2) and [{Cu(ada)3(bipy)}n·3nH2O] (3) (H2ada = adipic acid, phen = 1,10-phenanthroline and bipy = 2,2′-bipyridine) obtained under varying experimental conditions were characterized by spectral, electrochemical and thermal studies. The bonding modes and the spatial arrangements of the carboxylate dianion around the metal ions have been investigated employing FTIR, EPR and X-ray crystallographic studies. Present data revealed a six coordinate distorted octahedral geometry for 2 with a = 8.068, b = 9.788, c = 11.788 Å, α = 70.464, β = 75.109, γ = 72.063° and a five coordinate square pyramidal geometry for 3 with a = 9.509, b = 9.912, c = 12.656 Å, α = 70.486, β = 73.604, γ = 75.162°. The superoxide dismutase (SOD) mimic activities of the complexes are in the order 1 > 3 > 2.

Graphical abstractThe present ternary complexes [Cu(ada)(phen)(H2O)]·2H2O (1), [Co2(ada)2(phen)2(H2O)2] (2) and [{Cu(ada)3(bipy)}n·3nH2O] (3) were characterized by spectral, electrochemical and thermal studies. The bonding modes and the spatial arrangements of the carboxylate dianion around the metal ions have been investigated employing FTIR, EPR and X-ray crystallographic studies.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Mixed ligand complexes have been synthesized and characterized. ► X-ray data indicate 1D chain and 3D supramolecular networks. ► SOD mimic activities have also been evaluated.