Embedding 1D or 2D cobalt–carboxylate substrates in 3D coordination polymers exhibiting slow magnetic relaxation behaviors: crystal structures, high-field EPR, and magnetic studies. Issue 14 (27th March 2017) - Mao, Nannan
Abstract : A novel 3D coordination polymer containing 2D cobalt–carboxylate layer had been constructed, exhibiting slow magnetic relaxation. Abstract : By utilizing well-designed bifunctional ligands derived from 1 H -imidazole-4, 5-dicarboxylic acid, magnetic coordination polymers (CPs) that exhibit slow magnetic relaxation at the low temperature regions were constructed and further structurally characterized. In1, 1D cobalt–carboxyl chains were stabilized in the final structure. In contrast, by adjusting the length of the substituted arms on imidazole-4, 5-dicarboxylic acid, a novel 3D CP, 2 containing 2D 6 3 cobalt–carboxyl layer was obtained. A combination of Quantum Monte Carlo (QMC) simulations and the first-principles Density functional theory (DFT) calculations showed that compound2 features weak ferro- and antiferro-magnetic coupling mechanisms with two different super-exchange paths of −/+/− for syn – anti carboxylate bridges and −/−/− for syn – syn carboxylate bridges. Through HF-EPR measurements performed on polycrystalline samples over the frequency range of 60–260 GHz and field range of 0–12 T, the effective g -values of1 and2 were all larger than 2.00, and the signs of their D values were probably positive.