Discrete and 1D coordination polymeric chloro-bridged copper(II) dimers exhibiting ferro- and antiferromagnetic exchange coupling: Magneto-structural correlations and non-covalent interactions

The synthesis and characterization of two 1D coordination polymers [Cu2(MHL)Cl2][ClO4]2 · CH3CN · THF (2 · CH3CN · THF) and [Cu2(MPyPz)Cl2][ClO4]2 · CH3CN (3 · CH3CN), having repetitive View the MathML source{Cu2II(μ-Cl)2} units, of m -xylyl-based ligands with terminal tridentate (2-pyridyl)alkylamine (MHL = α,α′-bis[N -(2-pyridylethyl)-N -(2-pyridylmethyl)amino]-m -xylene) and (2-pyridyl)alkylamine/pyrazole (MPyPz = α,α′-bis[N -(2-pyridylethyl)-N -(pyrazol-1-ylmethyl)amino]-m -xylene) coordination have been accomplished. X-ray crystallographic studies reveal that the copper(II) centers in the recently reported dichloro-bridged discrete View the MathML source{Cu2II(μ-Cl)2} complex [{Cu(MeL)Cl}2][ClO4]2 (1) of a tridentate (2-pyridyl)alkylamine ligand [MeL = methyl[2-(2-pyridyl)ethyl](2-pyridylmethyl)amine], 2 · CH3CN · THF, and 3 · CH3CN have distorted square-pyramidal geometry, sharing a base-to-apex edge with parallel basal planes. Variable-temperature susceptibility measurements in the range of 2–300 K reveal antiferromagnetic for 1 [J (singlet–triplet energy gap) = −3.89 cm−1] and 2 · CH3CN · THF (J = −1.84 cm−1), and ferromagnetic for 3 · CH3CN (J = +6.27 cm−1) coupling. The complexes provide useful information for the magneto-structural correlations.