Dinuclear triply-bridged copper(II) compounds containing carboxylato bridges and di-2-pyridylamine as a ligand: synthesis, crystal structure, spectroscopic and magnetic properties

Three new triply-bridged dinuclear copper(II) compounds with carboxylato bridges, [Cu2(μ-O2CH)(μ-OH)(μ-Cl)(dpyam)2](PF6) (1), [Cu2(μ-O2CH)2(μ-OH)(dpyam)2](PF6) (2) and [Cu2(μ-O2CCH2CH3)2(μ-OH)(dpyam)2](ClO4) (3) have been synthesized and characterized crystallographically and spectroscopically. Both Cu(II) ions in 1 are bridged by three different ligands, providing a distorted trigonal bipyramidal geometry. The carboxylato ligands in both 2 and 3 exhibit different coordination modes. Each Cu(II) ion in 2 involves a distorted trigonal bipyramidal geometry while those of 3 are distorted square-pyramidal and intermediate between of SP and TBP. The magnetic susceptibility measurements (5-280 K) revealed a moderate ferromagnetic interaction between Cu(II) ions with J values of 79.7, 47.8 and 24.1 cm−1, for 1-3, respectively.