Field-Induced Slow Magnetic Relaxation and Gas Adsorption Properties of a Bifunctional Cobalt(II) Compound

A new compound, {[Co(bmzbc)2]·2DMF}n (JXNU-1, JXNU denotes Jiangxi Normal University), based on the 4-(benzimidazole-1-yl)benzoate (bmzbc–) ligand has been synthesized and structurally characterized. The Co(II) ions are bridged by the rod-like bmzbc– ligands to give a two-dimensional (2D) sheet wherein the Co(II) ions are spatially separated from each other by the long bmzbc– rods. The 2D sheets are further stacked into a 3D framework with 1D channels occluding the guest DMF molecules. Detailed magnetic studies show that the individual octahedral Co(II) ions in JXNU-1 exhibit field-induced slow magnetic relaxation, which is characteristic behavior of single-ion magnets (SIMs). The rarely observed positive value of zero-field splitting (ZFS) parameter D for the Co(II) ion in JXNU-1 demonstrates that JXNU-1 is a unique example of Co(II)-based SIMs with easy-plane anisotropy, which is also confirmed by the calculations. The microporous nature of JXNU-1 was established by measuring CO2 sorption isotherms. The...