6533b7d1fe1ef96bd125ca81

RESEARCH PRODUCT

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

subject

description

The synthesis and characterization of two 1D coordination polymers [Cu 2 (MHL)Cl 2 ][ClO 4 ] 2  · CH 3 CN · THF ( 2  · CH 3 CN · THF) and [Cu 2 (MPyPz)Cl 2 ][ClO 4 ] 2  · CH 3 CN ( 3  · CH 3 CN), having repetitive { Cu 2 II ( 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 { Cu 2 II ( μ -Cl ) 2 } complex [{Cu(MeL)Cl} 2 ][ClO 4 ] 2 ( 1 ) of a tridentate (2-pyridyl)alkylamine ligand [MeL = methyl[2-(2-pyridyl)ethyl](2-pyridylmethyl)amine], 2  · CH 3 CN · THF, and 3  · CH 3 CN 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  · CH 3 CN · THF ( J  = −1.84 cm −1 ), and ferromagnetic for 3  · CH 3 CN ( J  = +6.27 cm −1 ) coupling. The complexes provide useful information for the magneto-structural correlations.