Functional pyrazolylpyridine ligands in the design of metal complexes with tunable properties

(1H-Pyrazolyl)pyridines are highly demanded ligands in coordination chemistry. Compounds of this class are analogues of 2,2'-bipyridine ligands. They possess a number of benefits such as ready availability and the ease of synthesis. They can function as bridging counter-ions because of deprotonation of the NH group. This review summarizes the general methods for the synthesis of pyrazole derivatives substituted with pyridine in position 1 or 3(5). The approaches to the preparation of (1H-pyrazolyl)pyridine ligands, arranged according to the type of coordination, are integrated and analyzed. The coordination compounds of various metals, including noble and coin metals, formed on the basis of these ligands, are described. It was shown that the structure of pyrazolylpyridine determines the photophysical and chemical properties of the metal complex. The results can be used to establish the functional ligand — structure of the complex — property relationships.The bibliography includes 119 references.