Three-Dimensional Pillared-Layer 3d-4f Heterometallic Coordination Polymers With or Without Halides

Hydrothermal reactions of isonicotinic acid (Hina) and hemimellitic acid (H3hma) with lanthanide oxides and copper halides yielded 10 three-dimensional (3D) pillared-layer 3d-4f heterometallic coordination polymers (HCPs) with three structural types. They are formulated as [Ln2Cu2(μ2-X)­(hma)­(ina)4(H2O)2]n·2nH2O [Ln = La, X = Cl (I-A), Ln = La, X = Br (I-B), Ln = La, X = I (I-C), Ln = Nd, X = Cl (I-D), Ln = Nd, X = Br (I-E)], [Ln3Cu4.5I3.5(μ3-OH)­(hma)­(ina)6(H2O)]n·nH2O [Ln = Pr (II-A), Nd­(II-B)], and [LnCu0.5(hma)­(ina)­(H2O)]n·nH2O [Ln = La (III-A), Ce (III-B), Pr (III-C)]. All the HCPs are characterized by single-crystal X-ray diffractions. In type I structures, Ln-organic layers are pillared by halide-bridged dinuclear [Cu2(μ2-Cl)­(ina)4] units through Ln–O bonds. In type II structures, Ln-organic layers are pillared by two different kinds of monovalent Cu-based building units, namely, halide-free [Cu­(ina)2] and halide-containing [Cu8(μ3-I)6(μ4-I)­(ina)10]n. In type III structures, undulate heterometallic Cu­(II)–Ln­(III) layers are pillared by organic ina ligands via Ln–O and Cu–N bonds. The solid-state photoluminescent properties of I-D and II-B were also investigated at room temperature.