Magneto−Structural Correlation in a Metamagnetic Cobalt(II)-Based Pillared Trilayer Motif Constructed by Mixed Pyridyl-Type Carboxylate Ligands

The first structurally authenticated example of coordinated polymer featuring homometallic pillared-trilayer structure, [Co3(ina)2(pico)2(H2O)2]n (1), was built from mixed pyridyl-type monocarboxylates, isonicotinate (ina) and 3-hydroxypicolinate (pico), containing Kagomé-type [Co3(pico)2(H2O)2]n2n+ trilayers. The magnetic phase diagram of 1 shows a metamagnetic transition below 3.2 K, arising from the competing interactions between the antiferromagnetic intralayer couplings in different amplitudes with obviously noncompensated moments versus weak AF interlayer coupling.