Lanthanide–Organic Coordination Frameworks Showing New 5‑Connected Network Topology and 3D Ordered Array of Single-Molecular Magnet Behavior in the Dy Case

Five isostructural lanthanide–organic coordination frameworks with a unique 3-D 5-connected (47.63)­(43.65.​82) network, namely, [Ln(phen)­(L)] n (Ln = Dy for 1, Gd for 2, Ho for 3, Er for 4, and Tb for 5), have been prepared based on bridging 5-hydroxyisophthalic acid (H3 L) and chelating 1,10-phenanthroline (phen) coligand. Significantly, the Dy(III) complex 1 is an organized array of single-molecular magnets (SMMs), with frequency-dependent out-of-phase ac susceptibility signals and magnetization hysteresis at 4 K. Further analysis of the magnetic results can reveal that the SMM behavior of 1 should arise from the smaller ferromagnetic interaction between the Dy(III) ions. Complex 1 was also characterized by X-ray absorption spectra, which give the clear X-ray magnetic circular dichroism signal.