Syntheses, Crystal Structures, and Fluorescence Properties of 3d–4f Coordination Polymers LnNi (Ln = Er, Eu)

Abstract

Two novel 3d–4f coordination polymers [Ln(NiL)(Nipt)(C₂O₄)_0.5 · H₂O] · H₂O (Ln = Er (I), Eu (II) (H₂L = 2,3-dioxo-5,6,14,15-dibenzo-1,4,8,12-tetraazacyclopentadeca-7,13-dien; H₂Nip = 5-nit-roisophthalic acid) were obtained by using 5-nitroisophthalate and mononuclear macrocyclic oxamide complex NiL as co-ligand to react with Ln(NO₃)₃ ⋅ 6H₂O (Ln = Er, Eu) under solvothermal condition, and characterized by single crystal X-ray diffraction (CIF files CCDC nos. 1587618 (I) and 1587619 (II)). Two complexes are isostructural structure and exhibit a two-dimensional network architecture formed by [Ln(III)Ni(II)] units via the oxamide, 5-nitroisophthalate and oxalate bridges, and adjacent 2D structures are linked together with C–H⋅⋅⋅O and O–H⋅⋅⋅O intermolecular hydrogen bonds to form a 3D superamolecular architectures. The fluorescence properties of I and II are also characterized.