ИСТИНА

Ruthenium (II) polypyridine complexes are used as sensitizers in DSSC (Dye Sensitized Solar Cell). In solar cells, dye molecules adsorbed on the surface of a wide-gap semiconductor absorb electromagnetic radiation, become excited, and an electron is transferred to the conduction band of the semiconductor. There are two types of ligands in the structure of the complex: "donor" ligands, which are responsible for the absorption of light, and a ligand with "anchor" groups (for example, with carboxyl, phosphoryl, or sulfone groups), with the help of which covalent bonding to the semiconductor surface occurs. Ruthenium complexes absorb well solar radiation in the visible and near-IR ranges and have suitable redox potentials for cell operation. However, they do not have good stability, which reduces the cell life. The introduction of a cyclometallated fragment (a five-membered ring with a covalent metal-carbon bond) into the complex increases the stability of the complexes. Nevertheless, with an increase in the stability of the complexes, their optical and electrochemical properties deteriorate. Therefore, the efficiency of thiocyanate complexes has not yet been achieved for cyclometallated ones. To fine-tune the properties of the complexes, we propose various methods for modifying the donor ligand, such as changing the substituents in the aryl and benzimidazole fragments, expanding the conjugated system, and changing heteroatoms. In this work we introduce Ru (II) complexes with various 2-aryl-1,3-azoles and dimethyl ester of 4,4`-dicarboxy-2,2`-bipyridine (dmdcbp) with a general formula Ru(L)(dmdcbp)2PF6. All the complexes are characterized by NMR, UV-vis and luminescence spectroscopy, and cyclic voltammetry (CV), for some complexes crystals for X-ray structural analysis are obtained. Several complexes are mildly hydrolyzed and tested in a solar cell. It is shown that the obtained complexes are suitable for operation in a cell. The efficiency obtained depends non-monotonically on the donor properties of the substituents.