Magneto-structural properties of carbonato-bridged copper(ii) complexes: fixation of atmospheric CO2

Abstract

Two carbonato-bridged Cu(II) complexes, [Cu₃(dmMePEA)₃(μ₃-CO₃)(ClO₄)₃]ClO₄ (1) and [Cu₂(iptren)₂(μ₂-CO₃)](ClO₄)₂·H₂O (2), (dmMePEA = N-methyl(2-(2-pyridyl)ethyl)-(4-methoxy-3,5-dimethyl-2-pyridylmethyl)amine, iptren = tris[2-(isopropylamino)ethyl]amine) were synthesized through the atmospheric fixation of CO₂. The complexes were structurally and magnetically characterized. Tris(bidentate) and bis(monodentate) carbonato-bridge bonding modes were found in the two complexes. Variable temperature magnetic susceptibility (2–300 K) revealed weak bulk ferromagnetic coupling in complex 1 (J = 1.1 cm⁻¹) and very strong antiferromagnetic coupling in 2 (J = −167.7 cm⁻¹). The magnetic properties of the two complexes are discussed as a function of their structure parameters and in relation to those of other related complexes of similar carbonato-bridging bonding modes.