A Promising MgII‐Ion‐Selective Luminescent Probe: Structures and Properties of Dy–Mn Polymers with High Symmetry

Abstract

Two Dy–Mn polymers, {[Dy(L¹)₃Mn_1.5(H₂O)₃]⋅3.125 H₂O}_n (1, L¹=pyridine‐2,6‐dicarboxylic acid) and {[Dy(L²)₃Mn_1.5(H₂O)₆]⋅8.25 H₂O}_n (2, L²=4‐hydroxylpyridine‐2,6‐dicarboxylic acid), with high symmetry (S₆) have been prepared. Polymer 1 has a nanoporous 3D framework with channel of about 17.6 Å diameter, while 2 has a honeycomb‐type 2D structure with the cavity of approximately 14.4 Å diameter. In the construction of multidimensional porous polymers with 3d–4f mixed metals, it is the first observation that a ligand substituent effect leads to dramatic differences in the structures formed. Luminescent studies reveal that the emission intensities of 1 and 2 increase significantly upon the addition of Mg²⁺, whereas the introduction of other metal ions leaves the intensity unchanged or even weakens it; hence, both of them may serve as good candidates of Mg²⁺ luminescent probes. To our knowledge, complex 1 is also the first example of a 3d–4f metal‐based nanoporous polymer to exhibit luminescent selectivity for Mg²⁺. Magnetic susceptibility measurements reveal a rather rare ferromagnetic interaction in 2. Thermal gravimetric analyses and powder X‐ray diffraction investigations have also been performed, suggestive of high thermal stability of 1.