Compartment compounds as secondary building units for the preparation of 3d–4f coordination polymers: Preparation, structures, and properties of [NiLn(L)(NO3)2(4-pyp)(EtOH)] (Ln = Nd, Eu; H2L = 1,3-bis((3-methoxysalicylidene)amino)propane; 4-Hpyp = 4-pyridinepropionic acid)

Abstract

This paper describes the preparation of three compartment compounds and their use as secondary building units (SUBs) for the synthesis of Ni–Nd and Ni–Eu coordination polymers. A tetranuclear 3d–4f compartment compound, [NiNd(L)(NO3)2(μ-NO3)(H2O)(CH3CN)]2(H2O)2 (1) was prepared from [Ni(L)] (H2L=1,3-bis((3-methoxysalicylidene)amino)propane) and Nd(NO3)3·5(H2O) in acetonitrile under microwave-heating conditions. In addition, two dinuclear 3d–4f compartment compounds, [NiLn(L)(NO3)(CH3CN)(H2O)4](NO3)2(H2O) (Ln=Nd (2), Eu (3)), were synthesized at room temperature by stirring an acetonitrile solution containing [Ni(L)] and Ln(NO3)3·n(H2O). Compounds 2 and 3 were subsequently treated with 4-pyridinepropionic acid (4-Hpyp) to create the corresponding one-dimensional 3d–4f coordination polymers under microwave-heating conditions: [NiLn(L)(NO3)2(4-pyp)(EtOH)] (Ln=Nd (4), Eu (5)). The compartment ligand (L) in compounds 3 and 5 appears to exhibit quenching effects on the emission of the Eu3+ ions in both compounds.