In the last two decades, the design and synthesis of metal-organic frameworks (MOFs) has attracted more and more attentions due to their a unique structure and potential applications in the fields of magnetism[1, 2], ectrochemiluminescence[3, 4], supercapacitors[5–7], etc. Generally, to obtain metal organic framework materials with interesting topological structure and performance, many influencing factors should be considered, such as metal ions, organic ligand, temperature, pH value, etc., among which the selected ligand is crucial in the construction system. Because it can modulate the coordination mode and the flexibility of molecular skeleton to construct metal-organic framework materials. Among the candidate organic ligands, pyrazole carboxylic acid ligands have excellent coordination abilities and flexible coordination modes in the assembly of MOFs structure. Pyrazole carboxylic acid ligands can not only be acted as hydrogen bond donors, but also be as a acceptors to bring its topological structures have many diversities, so this type of ligand is widely used to construct MOFs with intriguing topological structures and outstanding performances.
Electrochemiluminescence (ECL) is a phenomenon that the luminescent body forms excited species on the electrode surface through high-energy electron transfer reaction, and then rapidly returns to the ground state through energy relaxation. It is an analytical technology combining electrochemical methods and chemiluminescence methods, and has been received considerable attention. As we know that, the Ir-, Ru- and Re- based complexes in the field of ECL has been used widely, but they are precious metals, so it limited their applications[11–14]. Therefore, it is a good choice to use transition metal complexes as ECL materials for the wide range and inexpensive. As our continuing work, our group have reported a series of transition metal framework based on pyrazole carboxylic ligands with excellent ECL performace [15, 16]. Thus, the use of transition metal ions and organic ligands to synthesize MOFs with highly luminescent efficiency has become an urgent issue.
In this work, we taken 3–(pyridin–2–yl)–1H–pyrazole–5–carboxylic acid (H2ppza) as ligand and synthesized a new MOF [Cd(µ–ppza)]n (1) under the hydrothermal condition which possessed 3D structure. Herein, we illustrate the synthesis, crystal structure, topology and the electrochemiluminescent performance of the title MOF.