Binuclear Copper(II) Complexes with Robsori‐Type Ligands. Synthesis, characterization, crystal structure, and magnetic properties

Abstract

AbstractThree binuclear copper(II) complexes, [Cu2(μ‐L)(μ‐N3)](ClO4)2′ 1‐5 EtOH (1), [Cu2(μ‐L)(μ‐MeO)(ClO4)]‐ClO4 ‐ EtOH (2) and [Cu2(μ‐L)(μ‐C3H3N2)](ClO4)2 · 2H2O, (3) where L is the pentadentale bridging ligand derived from 5‐(tert‐butyl)‐2‐hydroxybenzene‐1, 3‐dicarbaldehyde bis(benzoylhydrazone) (HL) were synthesized and characterized. The crystal‐structure determination of complex 2 provided the following crystal data: monoclinic, space group P21}/a, a = 11.412(2), b = 24.509(4), c = 14.833(4) Å, β = 104.41(2)°, K = 4018(3) Å3, Z = 4. The structure shows that the CuII ions are bridged by the endogenous phenolato O‐atom and by an exogenous bridge CH3O−. The analysis of variable‐temperature magnetic susceptibility data (4‐300 K.) indicates that there is an antiferromagnetic interaction between the CuII ions in these complexes with an exchange parameter (2J) of −119.1 cm−1 for complex 1 and −361.8 cm−1 for complex 3. The effect of some exogenous bridging ligands on magnetic coupling for this type of complex is suggested.