Two temperature-dependent 2D heterometallic Cd(Ⅱ)-Dy(Ⅲ)coordination polymers exhibiting slow magnetic relaxation and luminescence properties

Two unique two-dimensional(2D)Cd(Ⅱ)-Dy(Ⅲ)heterometallic coordination polymers,{[DyCd(HPMA)(PMA)_(2)(H_(2)O)_(4)]·2H_(2)O}_n(1)and[DyCd(PAA)(PMA)_(2)(H_(2)O)_(3)]_(n)(2,PAA^(-)=phenylacetate),were prepared successfully based on the phenylmalonic acid(H_(2)PMA).The construction of two polymers is sensitive to the reaction temperature and can be synthesized directionally at room temperature and 90℃,respectively.Complexes 1 and 2 display 2D layer structures that include dinuclear[Dy_(2)]cluster node and Dy(Ⅲ)-based 1D zigzag chain motif severally.The Dy(Ⅲ)-based units in two structures both are spaced well with the adjacent ones by the diamagnetic Cd(Ⅱ)-based moieties.The magnetic studies reveal that 1 and 2both display slow magnetic relaxation with temperature-dependent relaxation peaks producing an effective energy barrier(Δτ)of 74.5 and 32.1 K,separately.Furthermore,the solid-state photophysical properties of 1 and 2 show strong characteristic luminescent emissions of Dy(Ⅲ)ion in the visible region.