Interchain relay of antiferromagnetic ordering in 1D Co(II) coordination polymers via π–π interactions

Two new Phen-Co(II) complexes bridged by a hydroxyl isophthalate ligand, {[Co(dimphen)(HIA)]·H2O}n (1) and {[Co(phen)(HIA)]·H2O}n (2) (dimphen = 2,9-dimethyl-1,10-phenanthroline, phen = 1,10-phenanthroline, HIA = 5-hydroxyisophthalic acid), have been synthesized by carefully tuning the basicity of the reaction medium. In addition to single-crystal X-ray crystallography, the complexes were also characterized by IR spectroscopy, thermogravimetric and elemental analyses. Structurally, both complexes are 1D zigzag polymers with different metal nuclearities. Variable-temperature magnetic susceptibility measurements revealed ferromagnetic coupling within the chain while antiferromagnetic ordering is propagated in parallel running interchain via π–π interactions at low temperature.